diff --git a/scripts/BodyMath.cs b/scripts/BodyMath.cs
index 5c2a972..dad8fdd 100644
--- a/scripts/BodyMath.cs
+++ b/scripts/BodyMath.cs
@@ -3,36 +3,56 @@ using Godot;
 // Shared math for the chase-driven player bodies (hands, torso, arm segments).
 public static class BodyMath
 {
-    // Shortest-arc rotation taking `current` to `target`, as axis * angle (radians), world space.
-    // Never use Quaternion.GetAngle()/GetAxis() for servo errors: GetAngle() is 2*acos(W) and
-    // returns NaN when float rounding puts W at 1.0000001 (the Stage-1 chest collapse), and
-    // GetAxis() returns the raw un-normalized xyz once W > 1 - 1e-6 (servo gain collapses
-    // ~1000x inside 0.16 deg). atan2 is exact near zero and can't leave its domain.
-    public static Vector3 RotationError(Quaternion target, Quaternion current)
-    {
-        Quaternion q = target * current.Inverse();
-        if (q.W < 0f)
-            q = new Quaternion(-q.X, -q.Y, -q.Z, -q.W);
-        Vector3 v = new(q.X, q.Y, q.Z);
-        float s = v.Length();
-        if (s < 1e-9f)
-            return Vector3.Zero;
-        return v * (2f * Mathf.Atan2(s, q.W) / s);
-    }
+	// Shortest-arc rotation taking `current` to `target`, as axis * angle (radians), world space.
+	// Never use Quaternion.GetAngle()/GetAxis() for servo errors: GetAngle() is 2*acos(W) and
+	// returns NaN when float rounding puts W at 1.0000001 (the Stage-1 chest collapse), and
+	// GetAxis() returns the raw un-normalized xyz once W > 1 - 1e-6 (servo gain collapses
+	// ~1000x inside 0.16 deg). atan2 is exact near zero and can't leave its domain.
+	public static Vector3 RotationError(Quaternion target, Quaternion current)
+	{
+		Quaternion q = target * current.Inverse();
+		if (q.W < 0f)
+			q = new Quaternion(-q.X, -q.Y, -q.Z, -q.W);
+		Vector3 v = new(q.X, q.Y, q.Z);
+		float s = v.Length();
+		if (s < 1e-9f)
+			return Vector3.Zero;
+		return v * (2f * Mathf.Atan2(s, q.W) / s);
+	}
 
-    public static bool IsFinite(RigidBody3D body) =>
-        body.GlobalTransform.IsFinite() && body.LinearVelocity.IsFinite() && body.AngularVelocity.IsFinite();
+	// The horizontal direction a head faces, robust past vertical. The visor (-Z) projected flat
+	// flips 180° once you look down (or up) beyond vertical — chin to chest while crouching, or
+	// looking at your own feet — and everything built on it (torso yaw, stick direction) turned
+	// around. Looking down, the top of the head (+Y) points the way you face; looking up it points
+	// back. So: when the flat visor disagrees with the flat crown, the head is past vertical and the
+	// visor is reversed; near vertical the crown alone carries the direction. Zero if undefined.
+	public static Vector3 HeadFacing(Basis head)
+	{
+		Vector3 forward = -head.Z, up = head.Y;
+		Vector3 visor = new(forward.X, 0f, forward.Z);
+		Vector3 crown = new Vector3(up.X, 0f, up.Z) * -forward.Y;
+		if (visor.Dot(crown) < 0f)
+			visor = -visor;
+		Vector3 f = visor + crown * 0.5f;
+		return f.LengthSquared() > 1e-6f ? f.Normalized() : Vector3.Zero;
+	}
 
-    // Escape hatch: a non-finite body is unrecoverable for the solver and floods the renderer
-    // with !v.is_finite() errors — put it back on its target, motionless. Returns true if reset.
-    public static bool ResetIfNonFinite(RigidBody3D body, Transform3D target, string who)
-    {
-        if (IsFinite(body))
-            return false;
-        body.GlobalTransform = target;
-        body.LinearVelocity = Vector3.Zero;
-        body.AngularVelocity = Vector3.Zero;
-        GD.PushWarning($"{who}: non-finite body state, reset to target");
-        return true;
-    }
+	// Yaw (about +Y, Godot convention: 0 = facing -Z) of a horizontal direction.
+	public static float YawOf(Vector3 flat) => Mathf.Atan2(-flat.X, -flat.Z);
+
+	public static bool IsFinite(RigidBody3D body) =>
+		body.GlobalTransform.IsFinite() && body.LinearVelocity.IsFinite() && body.AngularVelocity.IsFinite();
+
+	// Escape hatch: a non-finite body is unrecoverable for the solver and floods the renderer
+	// with !v.is_finite() errors — put it back on its target, motionless. Returns true if reset.
+	public static bool ResetIfNonFinite(RigidBody3D body, Transform3D target, string who)
+	{
+		if (IsFinite(body))
+			return false;
+		body.GlobalTransform = target;
+		body.LinearVelocity = Vector3.Zero;
+		body.AngularVelocity = Vector3.Zero;
+		GD.PushWarning($"{who}: non-finite body state, reset to target");
+		return true;
+	}
 }
diff --git a/scripts/PlayerRagdoll.cs b/scripts/PlayerRagdoll.cs
index db650fb..913b90b 100644
--- a/scripts/PlayerRagdoll.cs
+++ b/scripts/PlayerRagdoll.cs
@@ -22,987 +22,1087 @@ using System.Collections.Generic;
 // All motors are PDs written as target velocities each tick; the force/torque limits are the strength.
 public partial class PlayerRagdoll : Node3D
 {
-    public const float BodyMass = 60f;                 // Nimso's character is 60 kg
-    // Muscles: PD gain (1/s), max commanded spin (rad/s), torque cap (N·m).
-    public const float SpineKp = 15f, SpineTorque = 400f;
-    public const float NeckKp = 20f, NeckTorque = 60f;
-    // Asymmetric by direction (Nimso; human strength tables): pulling the arm DOWN (lats/back —
-    // pull-ups, hanging, climbing) is roughly twice as strong as raising it (front delts — a weight
-    // held out front), and elbow flexion (biceps) beats extension.
-    public const float ShoulderKp = 20f, ShoulderTorque = 35f, ShoulderPullTorque = 100f;
-    public const float ElbowKp = 20f, ElbowTorque = 45f, ElbowFlexTorque = 70f;
-    public const float MuscleMaxSpin = 15f;
-    // Feed-forwards are derivatives of tracking: low-pass them or tracking jitter (±1–2 mm per
-    // sample) becomes hundreds of newtons of buzz (RagdollSpike REAL input mode).
-    public const float MuscleFeedForwardTau = 0.05f;   // s
-    public const float GroundFeedForwardTau = 0.12f;   // s
-    public const float GirdleKp = 30f, GirdleForce = 2000f;  // shoulder drive, linear part
-    // Hand guide (chest→hand drive): pulls the hand onto the controller; capped so the arm,
-    // not the guide, carries real loads.
-    public const float HandGuideKp = 40f, HandGuideForce = 40f, HandGuideMaxSpeed = 10f;
-    // STRUCTURAL strength: force along the arm (straight arm pressing on a ledge, hanging from a
-    // bar, carrying a bucket at your side) goes through bone and is strong; force across the arm
-    // needs muscle torque and stays at HandGuideForce. Cap = lerp(base, structural, alignment).
-    // Two arms ≈ 1.2 × body weight → two hands mantle/pull up, one can't (Nimso).
-    public const float HandStructuralForce = 400f;
-    public const float StructuralDeadband = 0.03f;
-    // Nimso's one global strength value: scales every muscle and the hand guides (menu slider).
-    public static float Strength = 1f;
-    public const float HandGuideAngularKp = 40f, HandGuideTorque = 25f;
-    // Ground control (world-space support on the pelvis, only while grounded).
-    public const float GroundFrequency = 4f;           // Hz
-    public const float GroundDamping = 1f;
-    public const float LegStrength = 4.5f;             // max support, × body weight (real legs brake a landing at 3–5 g; 2× sank ~0.4 m)
-    public const float GroundFriction = 1f;            // horizontal force ≤ this × support
-    public const float GroundProbeExtra = 0.3f;        // ground counts while within hip height + this
-    public const float MaxStepHeight = 0.35f;
-    public const float MaxRiseSpeed = 1.2f;            // m/s the legs lift the body toward its stance
-    public const float MaxSlopeDegrees = 35f;          // steeper ground gives no support (Nimso: "slopes beyond an angle can't be run up")          // higher ground under the hips isn't stood on unless the body got up there
-    public const float BracedAirControl = 150f;        // N of horizontal hip carry while airborne but braced on the hands (mantling)
-    public const float CrawlCarry = 300f;
-    public const float BlockedPush = 150f;             // N horizontal leg push while the hips are held back              // N: the torso lies on the floor in a crawl; knees/hands would push (not simulated)
-    public const float TorsoFriction = 0.3f;           // clothing on floor: lets a crawl slide
-    public const float LimbFriction = 0.25f;
-    // Lower-body collider: a box from the hips down to MaxStepHeight above the feet, so knee-high
-    // obstacles block walking (no walking over tables) while lower steps pass under it. It slides
-    // up into the torso when crouching and switches off when crawling (Nimso: legs don't snag).
-    public const float LegsMass = 6f;
-    public const float LegsKp = 30f, LegsForce = 3000f, LegsTorque = 400f;
-    public const float LegsOffAbove = 0.25f;           // collider disabled once slid this far above the hips
-    public const float MantleLift = 0.03f;             // braced + hips this far above the support goal = being lifted (legs tuck)
-    public const float UntuckDelay = 0.3f;             // s the tuck must be unneeded before the collider returns
-    // Balance: an implicit torque-capped motor from a world anchor to the pelvis (explicit torques
-    // let the arms' reaction torques set the whole trunk swinging).
-    public const float BalanceKp = 10f;
-    public const float BalanceTorque = 800f;
-    public const float AirBalanceShare = 0.3f;
-    // Play-space reconciliation.
-    public const float CameraRadius = 0.03f;           // sphere swept from the head's eye to the camera
-    public const float FreeSlack = 0.12f;              // camera leading the body's eye by more than this = body held back: stick stops pushing that way
-    public const float ViewDeadzone = 0.02f;           // m the head may lead the body before the view is eased back onto it
-    public const float ViewFollowTau = 0.04f;          // s
-    public const float MaxViewLead = 0.04f;            // hard: the head box reaches 2 cm in front of the eye
-    public const float FloorRecenterTau = 1f;          // s
-    public const float HeadGuideFrequency = 5f;        // Hz
-    public const float HeadGuideMass = 15f;            // kg effective (head + part of the trunk)
-    public const float HeadGuideForce = 250f;          // N
-    public const float ResetDistance = 1.5f;           // pelvis this far from its target → snap the whole body to the pose
-    // Geometry.
-    public const float LumbarFraction = 0.35f;         // lumbar joint height above the hips, × trunk
-    public const float PelvisLeanShare = 0.5f;         // share of the crouch lean taken by the hips
-    public static readonly Vector3 HeadCenterFromEye = new(0f, -0.005f, 0.08f);   // crown ~10 cm above the eyes, chin ~11 cm below (was 12.5 / 8.5)
-    public static readonly Vector3 HeadSize = new(0.16f, 0.21f, 0.2f);
-    public static readonly Vector3 HandSize = new(0.035f, 0.09f, 0.12f);
-    public const float WristOffset = TrueBodySolver.WristOffset;
-    public const float ElbowMaxFlex = 2.6f;            // rad (~150°)
-    // Sign of HingeJoint3D's angle/motor for a positive rotation of the child about the joint's
-    // +Z (measured by RagdollSpike's "hinge sign" phase).
-    public static float HingeSign = 1f;
-
-    // Collision layers (AGENTS.md): 3 body, 4 hands, 5 arms.
-    private const uint BodyLayer = 0b100, HandLayer = 0b1000, ArmLayer = 0b10000;
-    private const uint WorldMask = 0b1;
-
-    private sealed class Ball
-    {
-        public Generic6DofJoint3D Joint;
-        public RigidBody3D Parent, Child;
-        public Quaternion FrameA, FrameB;   // joint frame relative to each body
-        public float Kp;
-        public Quaternion PrevTarget;
-        public bool HasPrev;
-        public Vector3 Ff;
-    }
-
-    private sealed class Drive
-    {
-        public Generic6DofJoint3D Joint;
-        public Quaternion FrameA, FrameB;
-        public Vector3 AnchorA, AnchorB;    // anchor point, parent-local / child-local
-        public Quaternion PrevTarget;
-        public bool HasPrev;
-        public Vector3 Ff;
-    }
-
-    private sealed class Arm
-    {
-        public RigidBody3D Upper, Fore, Hand;
-        public Ball Wrist;
-        public HingeJoint3D Elbow;
-        public Drive Shoulder, Guide;
-        public float UpperLen, ForeLen;
-        public float PrevFlexTarget = -1f;
-        public float FlexFf;
-        public float GuideCap = HandGuideForce;
-        public float ShoulderCap = ShoulderTorque, ElbowCap = ElbowTorque;
-        public PhysicsBody3D Held;
-    }
-
-    public RigidBody3D Pelvis { get; private set; }
-    public RigidBody3D Chest { get; private set; }
-    public RigidBody3D Head { get; private set; }
-    public bool Built { get; private set; }
-    public bool Grounded { get; private set; }
-    public float GroundY => _footY;
-    public bool Braced { get; private set; }             // a hand touches or holds static world
-    public bool LegsSolid => _legsSolid;
-    public bool Lifted => _lifted;
-    // Horizontal direction in which the body is held back from the camera (zero if not): the stick
-    // must not keep moving the play space that way.
-    public Vector3 HeldBack { get; private set; }
-    // Really climbing: a hand holds static world, or the arms are lifting the body (mantle).
-    public bool Climbing => Built && (_arms[0].Held is StaticBody3D || _arms[1].Held is StaticBody3D || _lifted);
-    public RigidBody3D Legs { get; private set; }
-    public Vector3 Eye => Head.GlobalTransform * _eyeLocal;
-    public BodyProfile Profile { get; private set; }
-    public int Snaps { get; private set; }               // safety resets (NaN / too far) — should stay 0
-
-    private readonly Arm[] _arms = { new(), new() };
-    private readonly List<RigidBody3D> _bodies = new();
-    private Ball _spine, _neck;
-    private Vector3 _neckBaseToEye;                       // head frame, canonical (neck straight)
-    private float _trunk, _lumbar, _neckLen;
-    private Vector3 _eyeLocal;
-    private Vector3 _pelvisCenterLocal, _chestCenterLocal, _headCenterLocal; // from each body's proximal joint, in its basis
-    private readonly Dictionary<RigidBody3D, Transform3D> _targets = new();
-    private readonly Vector3[] _girdle = new Vector3[2];  // True Body shoulder offset, chest frame
-    private float _footY;
-    private float _supportGoalY;
-    private RigidBody3D _groundBody;
-    private Vector3 _groundPoint;
-    private float _tuckFree, _dt;
-    private PhysicsShapeQueryParameters3D _legsQuery;
-
-    private bool LegsSpaceFree(Vector3 center, Basis basis)
-    {
-        _legsQuery ??= new PhysicsShapeQueryParameters3D { Shape = Legs.GetChild<CollisionShape3D>(0).Shape, CollisionMask = WorldMask };
-        _legsQuery.Transform = new Transform3D(basis, center);
-        return GetWorld3D().DirectSpaceState.IntersectShape(_legsQuery, 1).Count == 0;
-    }
-    private Vector3 _goalVelocity;
-
-    private static float LowPass(float dt, float tau) => 1f - Mathf.Exp(-dt / tau);
-    private bool _lifted;
-    private float _legsHeight;
-    private Drive _legsDrive;
-    private bool _legsSolid = true;
-    private ProceduralLegs _legVisuals;
-    private float _appliedStrength = 1f;
-    private Vector3 _pelvisTargetPrev;
-    private bool _havePelvisPrev;
-
-    public RigidBody3D Hand(int side) => Built ? _arms[side].Hand : null;
-    public RigidBody3D UpperArm(int side) => Built ? _arms[side].Upper : null;
-    public RigidBody3D Forearm(int side) => Built ? _arms[side].Fore : null;
-    public IReadOnlyList<RigidBody3D> Bodies => _bodies;
-
-    // ---------------------------------------------------------------- build
-
-    public void Build(BodyProfile p, TrueBodySolver pose, Transform3D left, Transform3D right)
-    {
-        Clear();
-        Profile = p;
-        _trunk = TrueBodySolver.TrunkRatio * p.Stature;
-        _lumbar = LumbarFraction * _trunk;
-        _neckLen = Mathf.Max(0.05f, p.ShoulderDrop + TrueBodySolver.EyeToNeckPivot.Y - TrueBodySolver.NeckBaseAboveShoulders);
-        float m = BodyMass;
-        float s = p.Stature / 1.75f;
-
-        // Canonical pose (standing, level head, arms straight down-forward-out) in frame C at the
-        // current pelvis: joint cones/twists are centred on it and the elbow hinge's zero is a
-        // straight arm. The body is then moved onto the live pose.
-        Transform3D c = new(pose.YawBasis, pose.PelvisTarget);
-        Vector3 hip = Vector3.Zero;
-        Vector3 lumbar = new(0f, _lumbar, 0f);
-        Vector3 upperChest = new(0f, _trunk, 0f);
-        Vector3 neckBase = upperChest + new Vector3(0f, TrueBodySolver.NeckBaseAboveShoulders,
-            -(TrueBodySolver.ShouldersBehindEyes - TrueBodySolver.EyeToNeckPivot.Z));
-        Vector3 neckPivot = neckBase + new Vector3(0f, _neckLen, 0f);
-        _eyeLocal = -TrueBodySolver.EyeToNeckPivot;   // head body origin is set to its centre below
-        Vector3 headCenterFromPivot = _eyeLocal + HeadCenterFromEye;
-
-        Vector3 pelvisSize = new(0.17f * p.Stature, _lumbar + 0.06f, 0.18f * s);
-        _pelvisCenterLocal = new Vector3(0f, _lumbar * 0.5f - 0.03f, 0f);
-        float chestHeight = _trunk - _lumbar + TrueBodySolver.NeckBaseAboveShoulders;
-        Vector3 chestSize = new(2f * p.ShoulderHalfWidth * 0.75f, chestHeight, 0.2f * s);
-        _chestCenterLocal = new Vector3(0f, chestHeight * 0.5f, 0f);
-        _headCenterLocal = headCenterFromPivot;
-        _eyeLocal -= headCenterFromPivot;             // eye relative to the head body's centre
-
-        Color skin = new(0.85f, 0.72f, 0.6f), shirt = new(0.3f, 0.45f, 0.7f), pants = new(0.25f, 0.27f, 0.32f);
-        Pelvis = MakeBody("Pelvis", new BoxShape3D { Size = pelvisSize }, (0.142f + 0.139f + 0.322f) * m - LegsMass, BodyLayer, WorldMask, pants,
-            c * new Transform3D(Basis.Identity, hip + _pelvisCenterLocal), friction: TorsoFriction);
-        float standingHip = pose.PelvisTarget.Y - (pose.Eye.Y - p.EyeHeight);
-        _legsHeight = Mathf.Max(0.2f, standingHip - MaxStepHeight);
-        Legs = MakeBody("Legs", new BoxShape3D { Size = new Vector3(0.28f * s, _legsHeight, 0.2f * s) }, LegsMass, BodyLayer, WorldMask, pants,
-            c * new Transform3D(Basis.Identity, hip - new Vector3(0f, _legsHeight * 0.5f, 0f)), visible: false);
-        // Explicit inertia: the collider is switched off when tucked, and a body without an
-        // enabled shape has no inertia — its 400 N·m drive then tumbled the whole pelvis
-        // (owner 2.1 "body spinning" when crouched).
-        Legs.Inertia = new Vector3(_legsHeight * _legsHeight + 0.04f, 0.28f * 0.28f + 0.04f, _legsHeight * _legsHeight + 0.08f) * (LegsMass / 12f);
-        _footY = pose.Eye.Y - p.EyeHeight;
-        Chest = MakeBody("Chest", new BoxShape3D { Size = chestSize }, 0.216f * m, BodyLayer, WorldMask, shirt,
-            c * new Transform3D(Basis.Identity, lumbar + _chestCenterLocal), friction: TorsoFriction);
-        Head = MakeBody("Head", new BoxShape3D { Size = HeadSize * s }, 0.081f * m, BodyLayer, WorldMask, skin,
-            c * new Transform3D(Basis.Identity, neckPivot + headCenterFromPivot), friction: TorsoFriction);
-        // The neck: a box hanging under the head, same body.
-        Vector3 neckCenter = (neckBase + neckPivot) * 0.5f - (neckPivot + headCenterFromPivot);
-        Head.AddChild(new CollisionShape3D { Shape = new BoxShape3D { Size = new Vector3(0.09f * s, _neckLen, 0.09f * s) }, Position = neckCenter });
-        MeshInstance3D neckMesh = new() { Mesh = new BoxMesh { Size = new Vector3(0.09f * s, _neckLen, 0.09f * s) }, Position = neckCenter };
-        neckMesh.SetSurfaceOverrideMaterial(0, new StandardMaterial3D { AlbedoColor = skin, Roughness = 0.6f });
-        Head.AddChild(neckMesh);
-        _neckBaseToEye = neckPivot - TrueBodySolver.EyeToNeckPivot - neckBase;
-
-        // World anchor for the balance motor (no shape, linear motor force 0 = position free).
-        StaticBody3D anchor = new() { Name = "BalanceAnchor", CollisionLayer = 0, CollisionMask = 0 };
-        AddChild(anchor);
-        _balance = MakeDrive(anchor, Pelvis, Pelvis.GlobalTransform, 0f, BalanceTorque);
-        _legsDrive = MakeDrive(Pelvis, Legs, c * new Transform3D(Basis.Identity, hip), LegsForce, LegsTorque);
-        _legVisuals = new ProceduralLegs { Name = "LegVisuals" };
-        AddChild(_legVisuals);
-        _legVisuals.Setup(Pelvis, -_pelvisCenterLocal, p.Stature, pants, new Color(0.15f, 0.15f, 0.17f));
-        _balanceCap = BalanceTorque;
-
-        _spine = MakeBall(Pelvis, Chest, c * lumbar, c.Basis * TwistAlong(Vector3.Up), Mathf.DegToRad(60f), Mathf.DegToRad(35f), SpineKp, SpineTorque);
-        _neck = MakeBall(Chest, Head, c * neckBase, c.Basis * TwistAlong(Vector3.Up), Mathf.DegToRad(75f), Mathf.DegToRad(85f), NeckKp, NeckTorque);
-
-        for (int side = 0; side < 2; side++)
-        {
-            Arm a = _arms[side];
-            float sign = side == 0 ? -1f : 1f;
-            a.UpperLen = p.UpperArm;
-            a.ForeLen = p.Forearm;
-            Vector3 shoulder = upperChest + new Vector3(sign * p.ShoulderHalfWidth, 0f, 0f);
-            Vector3 dir = new Vector3(sign * 0.42f, -0.74f, -0.47f).Normalized();
-            Vector3 reference = Vector3.Down * 2f + Vector3.Back * 0.8f + new Vector3(sign * 0.3f, 0f, 0f);
-            Vector3 pole = (reference - dir * reference.Dot(dir)).Normalized();
-            Vector3 hinge = pole.Cross(dir).Normalized();
-            Basis bone = BoneBasis(dir, hinge);
-            Vector3 elbow = shoulder + dir * a.UpperLen;
-            Vector3 wrist = elbow + dir * a.ForeLen;
-            Vector3 handX = (Vector3.Right - dir * dir.X).Normalized();
-            Basis handBasis = new(handX, (-dir).Cross(handX), -dir);
-            Vector3 handOrigin = wrist + dir * WristOffset;
-            string n = side == 0 ? "Left" : "Right";
-
-            a.Upper = MakeBody(n + "UpperArm", new BoxShape3D { Size = new Vector3(0.085f * s, a.UpperLen, 0.085f * s) }, 0.028f * m, ArmLayer, WorldMask, shirt,
-                c * new Transform3D(bone, shoulder + dir * (a.UpperLen * 0.5f)), friction: LimbFriction);
-            a.Fore = MakeBody(n + "Forearm", new BoxShape3D { Size = new Vector3(0.07f * s, a.ForeLen - 0.01f, 0.07f * s) }, 0.016f * m, ArmLayer, WorldMask, skin,
-                c * new Transform3D(bone, elbow + dir * (a.ForeLen * 0.5f)), friction: LimbFriction);
-            a.Hand = MakeBody(n + "Hand", new BoxShape3D { Size = HandSize }, 0.006f * m, HandLayer, WorldMask | HandLayer,
-                side == 0 ? new Color(0.9f, 0.3f, 0.35f) : new Color(0.3f, 0.5f, 0.9f), c * new Transform3D(handBasis, handOrigin), friction: LimbFriction);
-            a.Hand.ContinuousCd = true;
-            a.Hand.ContactMonitor = true;
-            a.Hand.MaxContactsReported = 8;
-
-            a.Shoulder = MakeDrive(Chest, a.Upper, c * new Transform3D(Basis.Identity, shoulder), GirdleForce, ShoulderTorque);
-            a.Elbow = MakeHinge(a.Upper, a.Fore, c * elbow, c.Basis * new Basis(dir, hinge.Cross(dir), hinge));
-            a.Wrist = MakeBall(a.Fore, a.Hand, c * wrist, c.Basis * TwistAlong(dir), Mathf.DegToRad(80f), Mathf.DegToRad(90f), 0f, 0f);
-            a.Guide = MakeDrive(Chest, a.Hand, c * new Transform3D(handBasis, handOrigin), HandGuideForce, HandGuideTorque);
-        }
-
-        Built = true;
-        _havePelvisPrev = false;
-        _appliedStrength = 1f;
-        _legsSolid = true;
-        ApplyStrength();
-        SnapToPose(pose, left, right);
-        GD.Print($"PlayerRagdoll: built for stature {p.Stature:F2} m (arm {p.UpperArm:F3}+{p.Forearm:F3} m, {_bodies.Count} bodies)");
-    }
-
-    public void Clear()
-    {
-        foreach (Node child in GetChildren())
-            child.QueueFree();
-        foreach (Node child in GetChildren())
-            RemoveChild(child);
-        _bodies.Clear();
-        _targets.Clear();
-        for (int i = 0; i < 2; i++)
-            _arms[i] = new Arm();
-        Built = false;
-    }
-
-    // Twist axis (joint X) along `dir`.
-    private static Basis TwistAlong(Vector3 dir)
-    {
-        Vector3 helper = Mathf.Abs(dir.Y) < 0.9f ? Vector3.Up : Vector3.Right;
-        Vector3 z = dir.Cross(helper).Normalized();
-        return new Basis(dir, z.Cross(dir), z);
-    }
-
-    // Segment basis: Y along the bone, X = elbow hinge axis.
-    private static Basis BoneBasis(Vector3 boneDir, Vector3 hinge)
-    {
-        Vector3 x = (hinge - boneDir * hinge.Dot(boneDir)).Normalized();
-        return new Basis(x, boneDir, x.Cross(boneDir));
-    }
-
-    // NOTE (Box3D wrapper): friction is read only when the body's shapes are created — the material
-    // must be set before AddChild (setting it later silently does nothing).
-    private RigidBody3D MakeBody(string name, Shape3D shape, float mass, uint layer, uint mask, Color color, Transform3D at, bool visible = true, float friction = 1f)
-    {
-        RigidBody3D body = new() { Name = name, Mass = mass, CollisionLayer = layer, CollisionMask = mask, Transform = at, ContactMonitor = true, MaxContactsReported = 4,
-            PhysicsMaterialOverride = new PhysicsMaterial { Friction = friction } };
-        body.AddChild(new CollisionShape3D { Shape = shape });
-        if (shape is BoxShape3D box && layer != 0 && visible)
-        {
-            MeshInstance3D mesh = new() { Mesh = new BoxMesh { Size = box.Size } };
-            mesh.SetSurfaceOverrideMaterial(0, new StandardMaterial3D { AlbedoColor = color, Roughness = 0.6f });
-            body.AddChild(mesh);
-        }
-        AddChild(body);
-        _bodies.Add(body);
-        return body;
-    }
-
-    private static Quaternion Rot(Node3D n) => n.GlobalTransform.Basis.Orthonormalized().GetRotationQuaternion();
-
-    // Configure BEFORE AddChild (the node pushes everything to the server on enter-tree).
-    private Ball MakeBall(RigidBody3D parent, RigidBody3D child, Vector3 at, Basis frame, float cone, float twist, float kp, float torque)
-    {
-        Generic6DofJoint3D j = new() { Transform = new Transform3D(frame, at), NodeA = parent.GetPath(), NodeB = child.GetPath(), ExcludeNodesFromCollision = true };
-        j.SetParamX(Generic6DofJoint3D.Param.AngularLowerLimit, -twist);
-        j.SetParamX(Generic6DofJoint3D.Param.AngularUpperLimit, twist);
-        foreach (var set in new System.Action<Generic6DofJoint3D.Param, float>[] { j.SetParamY, j.SetParamZ })
-        {
-            set(Generic6DofJoint3D.Param.AngularLowerLimit, -cone);
-            set(Generic6DofJoint3D.Param.AngularUpperLimit, cone);
-        }
-        if (torque > 0f)
-        {
-            j.SetFlagX(Generic6DofJoint3D.Flag.EnableMotor, true);
-            j.SetFlagY(Generic6DofJoint3D.Flag.EnableMotor, true);
-            j.SetFlagZ(Generic6DofJoint3D.Flag.EnableMotor, true);
-            j.SetParamX(Generic6DofJoint3D.Param.AngularMotorForceLimit, torque);
-            j.SetParamY(Generic6DofJoint3D.Param.AngularMotorForceLimit, torque);
-            j.SetParamZ(Generic6DofJoint3D.Param.AngularMotorForceLimit, torque);
-        }
-        AddChild(j);
-        Quaternion jq = frame.Orthonormalized().GetRotationQuaternion();
-        return new Ball { Joint = j, Parent = parent, Child = child, FrameA = Rot(parent).Inverse() * jq, FrameB = Rot(child).Inverse() * jq, Kp = kp };
-    }
-
-    private Drive MakeDrive(PhysicsBody3D parent, RigidBody3D child, Transform3D at, float force, float torque)
-    {
-        Generic6DofJoint3D j = new() { Transform = at, NodeA = parent.GetPath(), NodeB = child.GetPath(), ExcludeNodesFromCollision = true };
-        foreach (var flag in new System.Action<Generic6DofJoint3D.Flag, bool>[] { j.SetFlagX, j.SetFlagY, j.SetFlagZ })
-        {
-            flag(Generic6DofJoint3D.Flag.EnableLinearLimit, false);
-            flag(Generic6DofJoint3D.Flag.EnableAngularLimit, false);
-            flag(Generic6DofJoint3D.Flag.EnableLinearMotor, true);
-            flag(Generic6DofJoint3D.Flag.EnableMotor, true);
-        }
-        foreach (var param in new System.Action<Generic6DofJoint3D.Param, float>[] { j.SetParamX, j.SetParamY, j.SetParamZ })
-        {
-            param(Generic6DofJoint3D.Param.LinearMotorForceLimit, force);
-            param(Generic6DofJoint3D.Param.AngularMotorForceLimit, torque);
-        }
-        AddChild(j);
-        Quaternion jq = at.Basis.Orthonormalized().GetRotationQuaternion();
-        return new Drive
-        {
-            Joint = j,
-            FrameA = Rot(parent).Inverse() * jq,
-            FrameB = Rot(child).Inverse() * jq,
-            AnchorA = parent.GlobalTransform.AffineInverse() * at.Origin,
-            AnchorB = child.GlobalTransform.AffineInverse() * at.Origin,
-        };
-    }
-
-    private HingeJoint3D MakeHinge(RigidBody3D parent, RigidBody3D child, Vector3 at, Basis frame)
-    {
-        HingeJoint3D j = new() { Transform = new Transform3D(frame, at), NodeA = parent.GetPath(), NodeB = child.GetPath(), ExcludeNodesFromCollision = true };
-        float lo = HingeSign > 0f ? 0f : -ElbowMaxFlex;
-        float hi = HingeSign > 0f ? ElbowMaxFlex : 0f;
-        j.SetFlag(HingeJoint3D.Flag.UseLimit, true);
-        j.SetParam(HingeJoint3D.Param.LimitLower, lo);
-        j.SetParam(HingeJoint3D.Param.LimitUpper, hi);
-        j.SetFlag(HingeJoint3D.Flag.EnableMotor, true);
-        j.SetParam(HingeJoint3D.Param.MotorMaxImpulse, ElbowTorque);
-        AddChild(j);
-        return j;
-    }
-
-    // ---------------------------------------------------------------- pose targets
-
-    // World transform every body should have in the True Body pose. The trunk is rebuilt top-down
-    // through the physical chain (upper chest → lumbar → hips) so a leaning chest doesn't drag
-    // the head off the camera; the hips take part of the crouch lean (hip hinge).
-    private void ComputeTargets(TrueBodySolver s, Transform3D left, Transform3D right, bool physicalArms = false, float dt = 0f)
-    {
-        Basis chest = s.ChestBasis;
-        // Hips take half of a crouch lean, all of it in a crawl (keeps them off the floor).
-        float share = Mathf.Lerp(PelvisLeanShare, 1f, Mathf.Clamp((s.Lean - TrueBodySolver.ChestLeanMax) / 0.5f, 0f, 1f));
-        Basis pelvis = s.YawBasis * new Basis(Vector3.Right, -s.Lean * share);
-        Vector3 lumbar = s.UpperChest - chest.Y * (_trunk - _lumbar);
-        Vector3 hip = lumbar - pelvis.Y * _lumbar;
-        _targets[Pelvis] = new Transform3D(pelvis, hip + pelvis * _pelvisCenterLocal);
-        _targets[Chest] = new Transform3D(chest, lumbar + chest * _chestCenterLocal);
-        _targets[Legs] = new Transform3D(s.YawBasis, hip - Vector3.Up * (_legsHeight * 0.5f));  // snap pose only; LegsDrive steps it
-        // Head + neck pivot at the neck base: orient like the camera, tilted by the small extra
-        // rotation that puts the body's eye on the camera (the True Body bends the neck at two points).
-        Vector3 eyeDir = s.HeadBasis * _neckBaseToEye;
-        Vector3 wantDir = s.Eye - s.NeckBase;
-        Quaternion tilt = eyeDir.LengthSquared() > 1e-8f && wantDir.LengthSquared() > 1e-8f
-            ? new Quaternion(eyeDir.Normalized(), wantDir.Normalized()) : Quaternion.Identity;
-        Basis head = new Basis(tilt) * s.HeadBasis;
-        _targets[Head] = new Transform3D(head, s.NeckBase + head * (_neckBaseToEye - _eyeLocal));
-
-        for (int side = 0; side < 2; side++)
-        {
-            Arm a = _arms[side];
-            Vector3 sh = s.Shoulder[side], el = s.Elbow[side], wr = s.Wrist[side];
-            Vector3 armDir = wr - sh;
-            armDir = armDir.LengthSquared() > 1e-8f ? armDir.Normalized() : chest * Vector3.Down;
-            Vector3 hinge = s.Pole[side].Cross(armDir);
-            hinge = hinge.LengthSquared() > 1e-8f ? hinge.Normalized() : chest.X;
-            Vector3 up = (el - sh).Normalized();
-            Vector3 fore = (wr - el).Normalized();
-            _girdle[side] = chest.Transposed() * (sh - (s.UpperChest + chest.X * ((side == 0 ? -1f : 1f) * Profile.ShoulderHalfWidth)));
-            _targets[a.Upper] = new Transform3D(BoneBasis(up, hinge), sh + up * (a.UpperLen * 0.5f));
-            _targets[a.Fore] = new Transform3D(BoneBasis(fore, hinge), el + fore * (a.ForeLen * 0.5f));
-            _targets[a.Hand] = (side == 0 ? left : right).Orthonormalized();
-
-            if (physicalArms)
-            {
-                // Re-aim the arm from the PHYSICAL shoulder. Horizontally the body may be held away from
-                // the camera (pressed against a ledge, leaning over a table): the arm reaches for the
-                // real hand. Vertically a sagging body keeps its arm pose (the aim point moves with
-                // the shoulder), so straight real arms stay straight virtual arms — pillars that hold
-                // you up when crawling or press you up a ledge (the hand guide adds the rest).
-                // Only a horizontal TRANSLATION of the reach: solved in the chest TARGET frame (the
-                // muscles stay local). Aiming in the physical chest frame made the shoulder muscles
-                // feed chest rotation back into the chest — a slow twist that tracking jitter
-                // excited into "chest slipping out of control" (owner playtest 2.1).
-                Transform3D chestPhys = Chest.GlobalTransform.Orthonormalized();
-                Vector3 shPhys = chestPhys * (a.Shoulder.AnchorA + _girdle[side]);
-                Vector3 held = shPhys - sh;
-                held.Y = 0f;
-                Transform3D ctrl = _targets[a.Hand];
-                ArmSolver solver = _armSolvers[side];
-                solver.Solve(sh, ctrl * new Vector3(0f, 0f, WristOffset) - held, chest, chest.X * (side == 0 ? -1f : 1f),
-                    ctrl.Basis, a.UpperLen, a.ForeLen, dt);
-                Vector3 d = solver.Wrist - sh;
-                Vector3 h = d.LengthSquared() > 1e-8f ? solver.Pole.Cross(d.Normalized()) : chest.X;
-                h = h.LengthSquared() > 1e-8f ? h.Normalized() : chest.X;
-                Vector3 u = (solver.Elbow - sh).Normalized(), f = (solver.Wrist - solver.Elbow).Normalized();
-                _targets[a.Upper] = new Transform3D(BoneBasis(u, h), sh + u * (a.UpperLen * 0.5f));
-                _targets[a.Fore] = new Transform3D(BoneBasis(f, h), solver.Elbow + f * (a.ForeLen * 0.5f));
-            }
-        }
-    }
-
-    private readonly ArmSolver[] _armSolvers = { new(), new() };
-
-    public Transform3D Target(RigidBody3D body) => _targets.TryGetValue(body, out Transform3D t) ? t : body.GlobalTransform;
-
-    // ---------------------------------------------------------------- per tick
-
-    public void Step(TrueBodySolver s, Transform3D left, Transform3D right, Vector3 leftVelocity, Vector3 rightVelocity, float floorY, float dt)
-    {
-        if (!Built)
-            return;
-        _dt = dt;
-        _floorYForHead = floorY;
-        ComputeTargets(s, left, right, physicalArms: true, dt);
-        foreach (RigidBody3D b in _bodies)
-        {
-            if (BodyMath.ResetIfNonFinite(b, Target(b), "PlayerRagdoll"))
-            {
-                Snaps++;
-                SnapToPose(s, left, right);
-                return;
-            }
-        }
-
-        Transform3D pelvisTarget = _targets[Pelvis];
-        if (Pelvis.GlobalPosition.DistanceTo(pelvisTarget.Origin) > ResetDistance)
-        {
-            GD.Print("PlayerRagdoll: body too far from the pose, snapped to it");
-            Snaps++;
-            SnapToPose(s, left, right);
-            return;
-        }
-
-        Muscle(_spine, _targets[Pelvis].Basis, _targets[Chest].Basis, dt);
-        Muscle(_neck, _targets[Chest].Basis, _targets[Head].Basis, dt);
-        if (Strength != _appliedStrength)
-            ApplyStrength();
-        Braced = false;
-        for (int side = 0; side < 2; side++)
-        {
-            Arm a = _arms[side];
-            ShoulderDrive(a, side, dt);
-            ElbowMuscle(a, dt);
-            HandGuide(a, _targets[a.Hand], side == 0 ? leftVelocity : rightVelocity);
-            Braced |= IsBraced(a);
-        }
-        GroundControl(pelvisTarget, floorY, dt);
-        HeadGuide(s, dt);
-        LegsDrive(s);
-        _legVisuals.Tick(_footY, Grounded, !_legsSolid, s.YawBasis, dt);
-    }
-
-    // Muscle = PD on the joint's relative rotation toward the relative rotation of the two TARGET
-    // bases (a local pose, not a world pin), written as the motor's target velocity in frame A.
-    // Feed-forward = the target's own relative spin, so a moving pose isn't chased with a lag of
-    // speed/Kp.
-    private static void Muscle(Ball b, Basis parentTarget, Basis childTarget, float dt)
-    {
-        Quaternion current = (Rot(b.Parent) * b.FrameA).Inverse() * (Rot(b.Child) * b.FrameB);
-        Quaternion target = (parentTarget.Orthonormalized().GetRotationQuaternion() * b.FrameA).Inverse()
-            * (childTarget.Orthonormalized().GetRotationQuaternion() * b.FrameB);
-        Vector3 raw = b.HasPrev && dt > 0f ? (BodyMath.RotationError(target, b.PrevTarget) / dt).LimitLength(MuscleMaxSpin) : Vector3.Zero;
-        b.Ff = b.Ff.Lerp(raw, LowPass(dt, MuscleFeedForwardTau));
-        b.PrevTarget = target;
-        b.HasPrev = true;
-        Vector3 w = (b.Ff + BodyMath.RotationError(target, current) * b.Kp).LimitLength(MuscleMaxSpin);
-        SetAngularVelocity(b.Joint, w);
-    }
-
-    private static void SetAngularVelocity(Generic6DofJoint3D j, Vector3 w)
-    {
-        j.SetParamX(Generic6DofJoint3D.Param.AngularMotorTargetVelocity, w.X);
-        j.SetParamY(Generic6DofJoint3D.Param.AngularMotorTargetVelocity, w.Y);
-        j.SetParamZ(Generic6DofJoint3D.Param.AngularMotorTargetVelocity, w.Z);
-    }
-
-    private static void SetLinearVelocity(Generic6DofJoint3D j, Vector3 v)
-    {
-        j.SetParamX(Generic6DofJoint3D.Param.LinearMotorTargetVelocity, v.X);
-        j.SetParamY(Generic6DofJoint3D.Param.LinearMotorTargetVelocity, v.Y);
-        j.SetParamZ(Generic6DofJoint3D.Param.LinearMotorTargetVelocity, v.Z);
-    }
-
-    // Elbow flexion (0 = straight) about the upper arm's hinge axis.
-    public float ElbowFlex(int side)
-    {
-        Arm a = _arms[side];
-        Basis u = a.Upper.GlobalTransform.Basis.Orthonormalized();
-        Vector3 f = a.Fore.GlobalTransform.Basis.Orthonormalized().Y;
-        return Mathf.Atan2(u.X.Dot(u.Y.Cross(f)), u.Y.Dot(f));
-    }
-
-    private void ElbowMuscle(Arm a, float dt)
-    {
-        int side = a == _arms[0] ? 0 : 1;
-        Vector3 up = _targets[a.Upper].Basis.Y, fore = _targets[a.Fore].Basis.Y;
-        float target = Mathf.Acos(Mathf.Clamp(up.Dot(fore), -1f, 1f));
-        float raw = a.PrevFlexTarget >= 0f && dt > 0f ? Mathf.Clamp((target - a.PrevFlexTarget) / dt, -MuscleMaxSpin, MuscleMaxSpin) : 0f;
-        a.FlexFf = Mathf.Lerp(a.FlexFf, raw, LowPass(dt, MuscleFeedForwardTau));
-        a.PrevFlexTarget = target;
-        float w = Mathf.Clamp(a.FlexFf + (target - ElbowFlex(side)) * ElbowKp, -MuscleMaxSpin, MuscleMaxSpin);
-        a.Elbow.SetParam(HingeJoint3D.Param.MotorTargetVelocity, HingeSign * w);
-        float cap = (w > 0f ? ElbowFlexTorque : ElbowTorque) * Mathf.Max(0.05f, Strength);
-        if (Mathf.Abs(cap - a.ElbowCap) > 0.5f)
-        {
-            a.ElbowCap = cap;
-            a.Elbow.SetParam(HingeJoint3D.Param.MotorMaxImpulse, cap);
-        }
-    }
-
-    // Head guide (Boneworks/BIMOS drive the head to the HMD): while standing on the ground, a force-
-    // capped PD pulls the character's eye onto the camera, so voluntary head motion (squats, leans,
-    // quick looks) doesn't leave the body lagging — a lag the riding view would otherwise turn into
-    // a permanent play-space offset. Off while airborne/climbing (no levitating by the head) or
-    // bracing on the hands (mantling, pushing off).
-    private void HeadGuide(TrueBodySolver s, float dt)
-    {
-        Vector3 goal = s.Eye + Vector3.Up * (_footY - _floorYForHead);
-        Vector3 raw = _haveHeadPrev && dt > 0f ? (goal - _headGoalPrev) / dt : Vector3.Zero;
-        _headGoalPrev = goal;
-        _haveHeadPrev = true;
-        if (raw.Length() > 10f)
-            raw = Vector3.Zero;
-        _headGoalVelocity = _headGoalVelocity.Lerp(raw, LowPass(dt, GroundFeedForwardTau));
-        // Only on your feet: hands bracing (mantling, pushing yourself) or crawling move the body by
-        // other means, and the view simply follows it.
-        if (!Grounded || Climbing || Braced)
-            return;
-        float w = Mathf.Tau * HeadGuideFrequency;
-        Vector3 force = ((goal - Eye) * (w * w) + (_headGoalVelocity - Head.LinearVelocity) * (2f * w)) * HeadGuideMass;
-        Head.ApplyCentralForce(force.LimitLength(HeadGuideForce));
-    }
-
-    private Vector3 _headGoalPrev, _headGoalVelocity;
-    private bool _haveHeadPrev;
-    private float _floorYForHead;
-
-    private void ApplyStrength()
-    {
-        _appliedStrength = Strength;
-        float k = Mathf.Max(0.05f, Strength);
-        SetAngularCap(_spine.Joint, SpineTorque * k);
-        SetAngularCap(_neck.Joint, NeckTorque * k);
-        foreach (Arm a in _arms)
-        {
-            SetAngularCap(a.Shoulder.Joint, ShoulderTorque * k);
-            a.ShoulderCap = ShoulderTorque * k;
-            a.ElbowCap = ElbowTorque * k;
-            SetAngularCap(a.Guide.Joint, HandGuideTorque * k);
-            a.Elbow.SetParam(HingeJoint3D.Param.MotorMaxImpulse, ElbowTorque * k);
-        }
-    }
-
-    private static void SetAngularCap(Generic6DofJoint3D j, float cap)
-    {
-        j.SetParamX(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
-        j.SetParamY(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
-        j.SetParamZ(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
-    }
-
-    private static void SetLinearCap(Generic6DofJoint3D j, float cap)
-    {
-        j.SetParamX(Generic6DofJoint3D.Param.LinearMotorForceLimit, cap);
-        j.SetParamY(Generic6DofJoint3D.Param.LinearMotorForceLimit, cap);
-        j.SetParamZ(Generic6DofJoint3D.Param.LinearMotorForceLimit, cap);
-    }
-
-    // A hand pressing on or holding static world (a ledge, a wall, a grabbed bar) — not the floor:
-    // hands on the floor while crawling don't lift the body.
-    private static bool IsBraced(Arm a)
-    {
-        if (a.Held is StaticBody3D)
-            return true;
-        foreach (Node3D n in a.Hand.GetCollidingBodies())
-            if (n is StaticBody3D && !n.IsInGroup(PropGrabber.NoGrabGroup))
-                return true;
-        return false;
-    }
-
-    // The lower-body collider hangs from the actual hips, its bottom never below a step above the
-    // feet; once it would have to slide far up into the torso (deep crouch, crawl) it stops colliding.
-    private void LegsDrive(TrueBodySolver s)
-    {
-        Transform3D pelvis = Pelvis.GlobalTransform;
-        Vector3 hip = pelvis * (-_pelvisCenterLocal);
-        float minCenter = _footY + MaxStepHeight + _legsHeight * 0.5f;
-        float center = Mathf.Max(hip.Y - _legsHeight * 0.5f, minCenter);
-        // Tuck (collider off, folded into the pelvis): deep crouch/crawl, or the hands bracing to
-        // lift the body (mantle, climbing — the knees come up). It STAYS tucked until it has been
-        // unneeded for a while AND its untucked spot is free: re-enabling inside a ledge face is
-        // what shoved the body off again and again (owner 2.2 "legs trying to get off the
-        // ground and instantly coming back").
-        bool climbingHold = _arms[0].Held is StaticBody3D || _arms[1].Held is StaticBody3D;
-        _lifted = Braced && (Pelvis.GlobalPosition.Y > _supportGoalY + MantleLift || climbingHold);
-        bool deep = center + _legsHeight * 0.5f >= hip.Y + LegsOffAbove;
-        bool wantTuck = deep || _lifted || (!_legsSolid && Braced);
-        _tuckFree = wantTuck ? 0f : _tuckFree + _dt;
-        Vector3 untucked = new(hip.X, center, hip.Z);
-        bool solid = _legsSolid ? !wantTuck : _tuckFree > UntuckDelay && LegsSpaceFree(untucked, s.YawBasis);
-        if (solid != _legsSolid)
-        {
-            _legsSolid = solid;
-            // The shape itself is disabled: Box3D keeps existing contacts when only the layer changes.
-            Legs.GetChild<CollisionShape3D>(0).SetDeferred(CollisionShape3D.PropertyName.Disabled, !solid);
-        }
-        if (!solid)
-            center = hip.Y;   // tucked into the pelvis, out of the way
-        Vector3 desired = new(hip.X, center, hip.Z);
-        Quaternion frameA = Rot(Pelvis) * _legsDrive.FrameA;
-        SetLinearVelocity(_legsDrive.Joint, frameA.Inverse() * ((desired - Legs.GlobalPosition) * LegsKp));
-        Quaternion target = (Rot(Pelvis) * _legsDrive.FrameA).Inverse() * (s.YawBasis.GetRotationQuaternion() * _legsDrive.FrameB);
-        Quaternion current = frameA.Inverse() * (Rot(Legs) * _legsDrive.FrameB);
-        SetAngularVelocity(_legsDrive.Joint, (BodyMath.RotationError(target, current) * LegsKp).LimitLength(MuscleMaxSpin));
-    }
-
-    // Shoulder = one drive: its linear motor keeps the humeral head on the chest's shoulder point
-    // shifted by the True Body girdle offset (shrug/protraction), its angular motor is the
-    // shoulder muscle (same PD + feed-forward as Muscle, parent = chest).
-    private void ShoulderDrive(Arm a, int side, float dt)
-    {
-        Drive d = a.Shoulder;
-        Transform3D chest = Chest.GlobalTransform.Orthonormalized();
-        Vector3 desired = chest * (d.AnchorA + _girdle[side]);
-        Vector3 err = desired - a.Upper.GlobalTransform * d.AnchorB;
-        Quaternion frameA = chest.Basis.GetRotationQuaternion() * d.FrameA;
-        SetLinearVelocity(d.Joint, frameA.Inverse() * (err * GirdleKp));
-
-        Quaternion current = frameA.Inverse() * (Rot(a.Upper) * d.FrameB);
-        // Local muscle: relative to the chest's TARGET pose (never to the physical chest — that
-        // closes a rotation feedback loop through the arms).
-        Quaternion target = (_targets[Chest].Basis.Orthonormalized().GetRotationQuaternion() * d.FrameA).Inverse()
-            * (_targets[a.Upper].Basis.Orthonormalized().GetRotationQuaternion() * d.FrameB);
-        Vector3 raw = d.HasPrev && dt > 0f ? (BodyMath.RotationError(target, d.PrevTarget) / dt).LimitLength(MuscleMaxSpin) : Vector3.Zero;
-        d.Ff = d.Ff.Lerp(raw, LowPass(dt, MuscleFeedForwardTau));
-        d.PrevTarget = target;
-        d.HasPrev = true;
-        Vector3 spin = (d.Ff + BodyMath.RotationError(target, current) * ShoulderKp).LimitLength(MuscleMaxSpin);
-        SetAngularVelocity(d.Joint, spin);
-        // Which way is the muscle moving the arm? Rotating the bone direction downward = pulling.
-        Vector3 bone = (a.Upper.GlobalTransform.Basis.Y).Normalized();
-        Vector3 boneMotion = (frameA * spin).Cross(bone);
-        float cap = (boneMotion.Y < 0f ? ShoulderPullTorque : ShoulderTorque) * Mathf.Max(0.05f, Strength);
-        if (Mathf.Abs(cap - a.ShoulderCap) > 0.5f)
-        {
-            a.ShoulderCap = cap;
-            SetAngularCap(d.Joint, cap);
-        }
-    }
-
-    // Force-capped pull of the hand onto the controller, reacting into the chest (arm muscles).
-    private void HandGuide(Arm a, Transform3D target, Vector3 targetVelocity)
-    {
-        Transform3D chest = Chest.GlobalTransform;
-        Vector3 anchor = chest * a.Guide.AnchorA;
-        Vector3 anchorVelocity = Chest.LinearVelocity + Chest.AngularVelocity.Cross(anchor - Chest.GlobalPosition);
-        Vector3 err = target.Origin - a.Hand.GlobalPosition;
-        Vector3 desired = (targetVelocity + err * HandGuideKp).LimitLength(HandGuideMaxSpeed);
-        Quaternion frameA = Rot(Chest) * a.Guide.FrameA;
-        Vector3 shoulder = a.Upper.GlobalTransform * a.Shoulder.AnchorB;
-        Vector3 axis = a.Hand.GlobalPosition - shoulder;
-        // Axial share of the error, with a 3 cm floor so a nearly-reached target's noisy error
-        // direction can't flip a held load into "structural".
-        // PUSH only (the hand wants to go further from the shoulder — straight arms pressing on a
-        // ledge): bone in compression. Pulling (shortening the arm: pull-ups, climbing) is muscle
-        // work — the asymmetric shoulder/elbow muscles do it, and one arm can't lift the body.
-        float align = axis.LengthSquared() > 1e-8f ? Mathf.Max(0f, err.Dot(axis.Normalized())) / (err.Length() + StructuralDeadband) : 0f;
-        // Structure only helps against something: a hand in free air reaching past its arm's
-        // length must not haul the whole body after it.
-        if (a.Held == null && a.Hand.GetContactCount() == 0)
-            align = 0f;
-        float cap = Mathf.Lerp(HandGuideForce, HandStructuralForce, align) * Mathf.Max(0.05f, Strength);
-        if (Mathf.Abs(cap - a.GuideCap) > 1f)
-        {
-            a.GuideCap = cap;
-            SetLinearCap(a.Guide.Joint, cap);
-        }
-        SetLinearVelocity(a.Guide.Joint, frameA.Inverse() * (desired - anchorVelocity));
-        // Angular: hand rotation onto the controller rotation, as a relative spin vs the chest.
-        Vector3 rotErr = BodyMath.RotationError(target.Basis.GetRotationQuaternion(), Rot(a.Hand));
-        Vector3 wWorld = (rotErr * HandGuideAngularKp).LimitLength(MuscleMaxSpin * 2f) - Chest.AngularVelocity;
-        SetAngularVelocity(a.Guide.Joint, frameA.Inverse() * wWorld);
-    }
-
-    // "Leg strength": a stiff, mass-scaled support holding the pelvis at its pose height above the
-    // ground and carrying it after the head horizontally (friction-limited), plus an upright/yaw
-    // balance motor (world anchor → pelvis). No ground → no support (falls); balance weakens in the air.
-    private void GroundControl(Transform3D target, float floorY, float dt)
-    {
-        Vector3 pos = Pelvis.GlobalPosition;
-        float hipAboveFloor = target.Origin.Y - floorY;
-        var query = PhysicsRayQueryParameters3D.Create(pos, pos + Vector3.Down * (hipAboveFloor + GroundProbeExtra + 0.5f), WorldMask);
-        Godot.Collections.Dictionary hit = GetWorld3D().DirectSpaceState.IntersectRay(query);
-        bool wasGrounded = Grounded;
-        Grounded = false;
-        _groundBody = null;
-        if (hit.Count > 0)
-        {
-            Vector3 point = (Vector3)hit["position"];
-            Vector3 normal = (Vector3)hit["normal"];
-            _groundBody = GodotObject.InstanceFromId((ulong)hit["collider_id"]) as RigidBody3D;  // Box3D: "collider" is null
-            _groundPoint = point;
-            bool inReach = pos.Y - point.Y < hipAboveFloor + GroundProbeExtra;
-            bool steep = normal.Y <= Mathf.Cos(Mathf.DegToRad(MaxSlopeDegrees));
-            if (inReach && steep && wasGrounded && point.Y <= _footY + MaxStepHeight)
-            {
-                // The foot of a too-steep slope: keep standing on the ground we're on (the legs
-                // collider stops us); dropping support here would collapse the body.
-                Grounded = true;
-            }
-            else if (inReach && !steep)
-            {
-                // Step rule: ground more than a step above the feet is only stood on once the
-                // hips are already well above it (climbed/mantled/landed there) — otherwise it's an
-                // obstacle the legs collider holds us back from, and the feet stay where they were.
-                // Higher ground climbed onto must be under the hips' back edge too (not just a
-                // pelvis centre hanging over the lip).
-                bool clear = point.Y <= _footY + MaxStepHeight || GroundBehindAt(pos, point.Y);
-                bool reachable = point.Y <= _footY + MaxStepHeight
-                    || ((!wasGrounded || _lifted || pos.Y - point.Y > 0.6f * hipAboveFloor) && clear);
-                Grounded = true;
-                if (reachable)
-                    _footY = point.Y;
-            }
-        }
-
-        // Feed-forward from the GOAL (pose + ground offset): when the play-space floor follows the
-        // ground, the pose target and the ground offset move by the same amount in opposite
-        // directions — differentiating the pose alone would launch the body.
-        Vector3 goalNow = target.Origin + Vector3.Up * (_footY - floorY);
-        Vector3 rawVelocity = _havePelvisPrev && dt > 0f ? (goalNow - _pelvisTargetPrev) / dt : Vector3.Zero;
-        _pelvisTargetPrev = goalNow;
-        _havePelvisPrev = true;
-        if (rawVelocity.Length() > 10f)
-            rawVelocity = Vector3.Zero;
-        _goalVelocity = _goalVelocity.Lerp(rawVelocity, LowPass(dt, GroundFeedForwardTau));
-        // Held back = the hips can't get to where the pose wants them (knee-high box, table edge,
-        // wall). Measured at the hips, not the head: the body tips over an obstacle, so the head
-        // may be right where the camera is while the hips are stuck.
-        Vector3 hipLag = new(target.Origin.X - pos.X, 0f, target.Origin.Z - pos.Z);
-        HeldBack = Grounded && hipLag.Length() > FreeSlack ? hipLag.Normalized() : Vector3.Zero;
-        Vector3 targetVelocity = _goalVelocity;
-
-        float weight = BodyMass * 9.8f;
-        if (Grounded)
-        {
-            // Pose heights are relative to the tracking floor; stand on the ground actually under us.
-            Vector3 goal = target.Origin + Vector3.Up * (GroundY - floorY);
-            _supportGoalY = goal.Y;
-            float w = Mathf.Tau * GroundFrequency;
-            Vector3 accel = (goal - pos) * (w * w) + (targetVelocity - Pelvis.LinearVelocity) * (2f * GroundDamping * w);
-            Vector3 force = accel * BodyMass;
-            // Vertical as a rate-limited velocity servo: full leg strength brakes a landing, but
-            // the legs raise the body at most MaxRiseSpeed — they can push, not pull, so a hard push
-            // toward a higher stance (onto a ledge) would otherwise overshoot into a jump.
-            float riseVelocity = Mathf.Clamp((goal.Y - pos.Y) * w, -3f, MaxRiseSpeed) + targetVelocity.Y;
-            float verticalAccel = (riseVelocity - Pelvis.LinearVelocity.Y) * (2f * GroundDamping * w);
-            float support = Mathf.Clamp(verticalAccel * BodyMass + weight, 0f, LegStrength * weight);
-            float carry = Mathf.Max(GroundFriction * support, _legsSolid ? 0f : CrawlCarry);
-            // Hips held back by an obstacle: lean on it, don't bulldoze — full leg force tipped the
-            // body over knee-high boxes and steep slopes (and the riding view tipped with it).
-            if (HeldBack != Vector3.Zero)
-                carry = Mathf.Min(carry, BlockedPush);
-            Vector3 horizontal = new Vector3(force.X, 0f, force.Z).LimitLength(carry);
-            Pelvis.ApplyCentralForce(horizontal + Vector3.Up * support);
-            // Newton's third law: standing on something movable (seesaw, plank, crate) pushes it
-            // down — the feet aren't physical, so the reaction is applied where the ground ray hit.
-            if (_groundBody != null && IsInstanceValid(_groundBody))
-                _groundBody.ApplyForce(-(horizontal + Vector3.Up * support), _groundPoint - _groundBody.GlobalPosition);
-        }
-        else if (Braced)
-        {
-            // Hanging/mantling on the hands: the hips still drift after the head a little, so you can
-            // shift your weight over a ledge you're pressing yourself up onto.
-            Vector3 lead = target.Origin - pos;
-            lead.Y = 0f;
-            Vector3 v = Pelvis.LinearVelocity;
-            v.Y = 0f;
-            Pelvis.ApplyCentralForce(((lead * 20f - v * 8f) * BodyMass).LimitLength(BracedAirControl));
-        }
-
-        Vector3 rotErr = BodyMath.RotationError(target.Basis.GetRotationQuaternion(), Rot(Pelvis));
-        Vector3 spin = (rotErr * BalanceKp).LimitLength(MuscleMaxSpin);
-        SetAngularVelocity(_balance.Joint, _balance.FrameA.Inverse() * spin);  // anchor = world frame
-        float cap = BalanceTorque * (Grounded ? 1f : AirBalanceShare);
-        if (cap != _balanceCap)
-        {
-            _balanceCap = cap;
-            _balance.Joint.SetParamX(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
-            _balance.Joint.SetParamY(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
-            _balance.Joint.SetParamZ(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
-        }
-    }
-
-    private Drive _balance;
-    private float _balanceCap;
-
-    // ---------------------------------------------------------------- play space
-
-    // How the driver should move its play-space origin after the last physics step. ONE rule, always,
-    // in all directions (Boneworks/BIMOS: the rig rides the body): the camera rides the character's
-    // eye. Head motion leads the body by at most ViewDeadzone (eased) / MaxViewLead (hard) — less
-    // than the head box reaches in front of the eye, so the view stays inside the head. A sphere
-    // swept eye→camera snaps the view back at once when geometry is in the way.
-    // This does NOT feed back into the pose: the True Body reads the head relative to the play-space
-    // floor (crouch = local head height) and ground control re-bases its goal onto the real ground
-    // (footY − floorY), so moving the play space vertically changes neither. (2.3 split height off
-    // to a separate floor-follow out of fear of that loop; the two then fought over the same height,
-    // and landings left the view hanging above a sinking body — owner 2.4.)
-    public Vector3 OriginCorrection(Vector3 camera, float floorY, float dt)
-    {
-        if (!Built)
-            return Vector3.Zero;
-        Vector3 eye = Eye;
-        Vector3 lead = camera - eye;
-        Vector3 correction = Vector3.Zero;
-        if (lead.LengthSquared() > 1e-8f)
-        {
-            _cameraQuery ??= new PhysicsShapeQueryParameters3D { Shape = new SphereShape3D { Radius = CameraRadius }, CollisionMask = WorldMask };
-            _cameraQuery.Transform = new Transform3D(Basis.Identity, eye);
-            _cameraQuery.Motion = lead;
-            float[] fractions = GetWorld3D().DirectSpaceState.CastMotion(_cameraQuery);
-            float safe = fractions.Length > 0 ? fractions[0] : 1f;
-            if (safe < 1f)
-                correction = -lead * (1f - safe);
-            Vector3 rest = lead + correction;
-            if (rest.Length() > ViewDeadzone)
-                correction -= rest * (1f - ViewDeadzone / rest.Length()) * (1f - Mathf.Exp(-dt / ViewFollowTau));
-            rest = lead + correction;
-            if (rest.Length() > MaxViewLead)
-                correction -= rest * (1f - MaxViewLead / rest.Length());
-        }
-        // Slow re-centering of the play-space floor onto the real ground while standing: removes the
-        // small height offsets the riding view picks up (a transient lag, a landing). The pose and the
-        // head guide are re-based on the real ground, so this only brings the camera onto the eye —
-        // the same direction as the follow above, never against it.
-        if (Grounded)
-            correction.Y += (_footY - floorY) * (1f - Mathf.Exp(-dt / FloorRecenterTau));
-        // The pose target moves with the play space: a correction is not intended motion, so it
-        // must not show up in ground control's feed-forward (that loop ran away at 7 m/s).
-        _pelvisTargetPrev += correction;
-        _headGoalPrev += correction;
-        return correction;
-    }
-
-    private PhysicsShapeQueryParameters3D _cameraQuery;
-
-    // Second ground ray 12 cm behind the hips (toward the body's back): ground at least `groundY`.
-    private bool GroundBehindAt(Vector3 pelvisPos, float groundY)
-    {
-        Vector3 back = Pelvis.GlobalTransform.Basis.Z;
-        back.Y = 0f;
-        back = back.LengthSquared() > 1e-6f ? back.Normalized() * 0.12f : Vector3.Zero;
-        var query = PhysicsRayQueryParameters3D.Create(pelvisPos + back, pelvisPos + back + Vector3.Down * 3f, WorldMask);
-        Godot.Collections.Dictionary hit = GetWorld3D().DirectSpaceState.IntersectRay(query);
-        return hit.Count > 0 && ((Vector3)hit["position"]).Y > groundY - 0.05f;
-    }
-
-    public void TeleportBy(Transform3D delta)
-    {
-        if (!Built)
-            return;
-        foreach (RigidBody3D b in _bodies)
-        {
-            b.GlobalTransform = delta * b.GlobalTransform;
-            b.LinearVelocity = delta.Basis * b.LinearVelocity;
-            b.AngularVelocity = delta.Basis * b.AngularVelocity;
-        }
-        _pelvisTargetPrev = delta * _pelvisTargetPrev;
-        _footY += delta.Origin.Y;
-        foreach (RigidBody3D b in _bodies)
-            b.ResetPhysicsInterpolation();
-    }
-
-    public void SnapToPose(TrueBodySolver s, Transform3D left, Transform3D right)
-    {
-        ComputeTargets(s, left, right);
-        foreach (RigidBody3D b in _bodies)
-        {
-            b.GlobalTransform = Target(b);
-            b.LinearVelocity = Vector3.Zero;
-            b.AngularVelocity = Vector3.Zero;
-        }
-        // The hands sit at the wrist end of the solved arm, not at a possibly unreachable controller.
-        for (int side = 0; side < 2; side++)
-        {
-            Arm a = _arms[side];
-            Basis hb = _targets[a.Hand].Basis;
-            a.Hand.GlobalTransform = new Transform3D(hb, s.Wrist[side] - hb * new Vector3(0f, 0f, WristOffset));
-        }
-        _havePelvisPrev = false;
-        foreach (RigidBody3D b in _bodies)
-            b.ResetPhysicsInterpolation();
-    }
-
-    // Collision exceptions between a held prop and that arm's segments (its hand is excluded by
-    // the grab weld itself) — a forearm wrapped around a held object must not fight it.
-    public void SetHeld(int side, PhysicsBody3D prop)
-    {
-        if (!Built)
-            return;
-        Arm a = _arms[side];
-        if (a.Held != null && IsInstanceValid(a.Held) && a.Held != _arms[1 - side].Held)
-        {
-            a.Upper.RemoveCollisionExceptionWith(a.Held);
-            a.Fore.RemoveCollisionExceptionWith(a.Held);
-        }
-        a.Held = prop;
-        if (prop != null)
-        {
-            a.Upper.AddCollisionExceptionWith(prop);
-            a.Fore.AddCollisionExceptionWith(prop);
-        }
-    }
+	public const float BodyMass = 60f;                 // Nimso's character is 60 kg
+	// Muscles: PD gain (1/s), max commanded spin (rad/s), torque cap (N·m).
+	public const float SpineKp = 15f, SpineTorque = 400f;
+	public const float NeckKp = 20f, NeckTorque = 60f;
+	// Asymmetric by direction (Nimso; human strength tables): pulling the arm DOWN (lats/back —
+	// pull-ups, hanging, climbing) is roughly twice as strong as raising it (front delts — a weight
+	// held out front), and elbow flexion (biceps) beats extension.
+	public const float ShoulderKp = 20f, ShoulderTorque = 35f, ShoulderPullTorque = 100f;
+	public const float ElbowKp = 20f, ElbowTorque = 45f, ElbowFlexTorque = 70f;
+	public const float MuscleMaxSpin = 15f;
+	// Feed-forwards are derivatives of tracking: low-pass them or tracking jitter (±1–2 mm per
+	// sample) becomes hundreds of newtons of buzz (RagdollSpike REAL input mode).
+	public const float MuscleFeedForwardTau = 0.05f;   // s
+	public const float GroundFeedForwardTau = 0.12f;   // s
+	public const float GirdleKp = 30f, GirdleForce = 2000f;  // shoulder drive, linear part
+	// Hand guide (chest→hand drive): pulls the hand onto the controller; capped so the arm,
+	// not the guide, carries real loads.
+	public const float HandGuideKp = 40f, HandGuideForce = 40f, HandGuideMaxSpeed = 10f;
+	// STRUCTURAL strength: force along the arm (straight arm pressing on a ledge, hanging from a
+	// bar, carrying a bucket at your side) goes through bone and is strong; force across the arm
+	// needs muscle torque and stays at HandGuideForce. Cap = lerp(base, structural, alignment).
+	// Two arms ≈ 1.2 × body weight → two hands mantle/pull up, one can't (Nimso).
+	public const float HandStructuralForce = 400f;
+	public const float StructuralDeadband = 0.03f;
+	// Nimso's one global strength value: scales every muscle and the hand guides (menu slider).
+	public static float Strength = 1f;
+	public const float HandGuideAngularKp = 40f, HandGuideTorque = 25f;
+	// Ground control (world-space support on the pelvis, only while grounded).
+	public const float GroundFrequency = 4f;           // Hz
+	public const float GroundDamping = 1f;
+	public const float LegStrength = 4.5f;             // max support, × body weight (real legs brake a landing at 3–5 g; 2× sank ~0.4 m)
+	public const float GroundFriction = 1f;            // horizontal force ≤ this × support
+	public const float GroundProbeExtra = 0.3f;        // ground counts while within hip height + this
+	public const float MaxStepHeight = 0.35f;
+	public const float MaxRiseSpeed = 1.2f;            // m/s the legs lift the body toward its stance
+	// Landing (owner 2.6: the sink is feedback, it just had to be followed by the view): falling legs
+	// only touch down when the hips are within their real reach of the ground. Before, support
+	// began GroundProbeExtra early and braked the fall in the air — no dip at all. Now LegStrength
+	// stops the body BELOW its stance, so the dip scales with the impact: ~0.13 m from a hop,
+	// ~0.3 m from 1 m, legs fully folded from a big fall (Boneworks) — then the normal rise.
+	public const float LandingReach = 0.05f;           // m past the pose's hip height
+	public const float AbsorbTime = 0.4f;              // s after a hard touchdown the head guide stays off (it would hold the dip up)
+	// Jump (right A): a short countermovement dip, then the legs push JumpForce over the stroke up to
+	// full extension. Takeoff speed is physics — v² = 2·(F/m − g)·stroke — so a crouch before
+	// the press (real or stick) jumps higher: ~0.45 m standing, ~0.7 m from a deep crouch.
+	public const float JumpForce = 2.4f;               // × body weight
+	public const float JumpDip = 0.2f;                 // m the hips drop first when pressed from standing
+	public const float JumpExtension = 0.06f;          // m above the standing hips at toe-off
+	public const float JumpMaxStroke = 0.5f;
+	public const float JumpBuffer = 0.15f;             // s a press is remembered before touchdown
+	public const float CoyoteTime = 0.12f;             // s after leaving the ground a jump still works
+	public const float MaxSlopeDegrees = 35f;          // steeper ground gives no support (Nimso: "slopes beyond an angle can't be run up")          // higher ground under the hips isn't stood on unless the body got up there
+	public const float BracedAirControl = 150f;        // N of horizontal hip carry while airborne but braced on the hands (mantling)
+	public const float CrawlCarry = 300f;
+	public const float BlockedPush = 150f;             // N horizontal leg push while the hips are held back              // N: the torso lies on the floor in a crawl; knees/hands would push (not simulated)
+	public const float TorsoFriction = 0.3f;           // clothing on floor: lets a crawl slide
+	public const float LimbFriction = 0.25f;
+	// Lower-body collider: a box from the hips down to MaxStepHeight above the feet, so knee-high
+	// obstacles block walking (no walking over tables) while lower steps pass under it. It slides
+	// up into the torso when crouching and switches off when crawling (Nimso: legs don't snag).
+	public const float LegsMass = 6f;
+	public const float LegsKp = 30f, LegsForce = 3000f, LegsTorque = 400f, LegsMaxSpeed = 1.5f;
+	public const float LegsOffAbove = 0.25f;           // collider disabled once slid this far above the hips
+	public const float MantleLift = 0.03f;             // braced + hips this far above the support goal = being lifted (legs tuck)
+	public const float UntuckDelay = 0.3f;             // s the tuck must be unneeded before the collider returns
+	// Balance: an implicit torque-capped motor from a world anchor to the pelvis (explicit torques
+	// let the arms' reaction torques set the whole trunk swinging).
+	public const float BalanceKp = 10f;
+	public const float BalanceTorque = 800f;
+	public const float AirBalanceShare = 0.3f;
+	// Play-space reconciliation.
+	public const float CameraRadius = 0.03f;           // sphere swept from the head's eye to the camera
+	public const float FreeSlack = 0.12f;              // camera leading the body's eye by more than this = body held back: stick stops pushing that way
+	public const float ViewDeadzone = 0.02f;           // m the head may lead the body before the view is eased back onto it
+	public const float ViewFollowTau = 0.04f;          // s
+	public const float MaxViewLead = 0.04f;            // hard: the head box reaches 2 cm in front of the eye
+	public const float FloorRecenterTau = 1f;          // s
+	public const float HeadGuideFrequency = 5f;        // Hz
+	public const float HeadGuideMass = 15f;            // kg effective (head + part of the trunk)
+	public const float HeadGuideForce = 250f;          // N
+	public const float ResetDistance = 1.5f;           // pelvis this far from its target → snap the whole body to the pose
+	// Geometry.
+	public const float LumbarFraction = 0.35f;         // lumbar joint height above the hips, × trunk
+	public const float PelvisLeanShare = 0.5f;         // share of the crouch lean taken by the hips
+	public static readonly Vector3 HeadCenterFromEye = new(0f, -0.005f, 0.08f);   // crown ~10 cm above the eyes, chin ~11 cm below (was 12.5 / 8.5)
+	public static readonly Vector3 HeadSize = new(0.16f, 0.21f, 0.2f);
+	public static readonly Vector3 HandSize = new(0.035f, 0.09f, 0.12f);
+	public const float WristOffset = TrueBodySolver.WristOffset;
+	public const float ElbowMaxFlex = 2.6f;            // rad (~150°)
+	// Sign of HingeJoint3D's angle/motor for a positive rotation of the child about the joint's
+	// +Z (measured by RagdollSpike's "hinge sign" phase).
+	public static float HingeSign = 1f;
+
+	// Collision layers (AGENTS.md): 3 body, 4 hands, 5 arms.
+	private const uint BodyLayer = 0b100, HandLayer = 0b1000, ArmLayer = 0b10000;
+	private const uint WorldMask = 0b1;
+
+	private sealed class Ball
+	{
+		public Generic6DofJoint3D Joint;
+		public RigidBody3D Parent, Child;
+		public Quaternion FrameA, FrameB;   // joint frame relative to each body
+		public float Kp;
+		public Quaternion PrevTarget;
+		public bool HasPrev;
+		public Vector3 Ff;
+	}
+
+	private sealed class Drive
+	{
+		public Generic6DofJoint3D Joint;
+		public Quaternion FrameA, FrameB;
+		public Vector3 AnchorA, AnchorB;    // anchor point, parent-local / child-local
+		public Quaternion PrevTarget;
+		public bool HasPrev;
+		public Vector3 Ff;
+	}
+
+	private sealed class Arm
+	{
+		public RigidBody3D Upper, Fore, Hand;
+		public Ball Wrist;
+		public HingeJoint3D Elbow;
+		public Drive Shoulder, Guide;
+		public float UpperLen, ForeLen;
+		public float PrevFlexTarget = -1f;
+		public float FlexFf;
+		public float GuideCap = HandGuideForce;
+		public float ShoulderCap = ShoulderTorque, ElbowCap = ElbowTorque;
+		public PhysicsBody3D Held;
+	}
+
+	public RigidBody3D Pelvis { get; private set; }
+	public RigidBody3D Chest { get; private set; }
+	public RigidBody3D Head { get; private set; }
+	public bool Built { get; private set; }
+	public bool Grounded { get; private set; }
+	public float GroundY => _footY;
+	public bool Braced { get; private set; }             // a hand touches or holds static world
+	public bool LegsSolid => _legsSolid;
+	public bool Lifted => _lifted;
+	// Horizontal direction in which the body is held back from the camera (zero if not): the stick
+	// must not keep moving the play space that way.
+	public Vector3 HeldBack { get; private set; }
+	public bool Jumping => _jump != JumpPhase.None;
+	// Really climbing: a hand holds static world, or the arms are lifting the body (mantle).
+	public bool Climbing => Built && (_arms[0].Held is StaticBody3D || _arms[1].Held is StaticBody3D || _lifted);
+	public RigidBody3D Legs { get; private set; }
+	public Vector3 Eye => Head.GlobalTransform * _eyeLocal;
+	public BodyProfile Profile { get; private set; }
+	public int Snaps { get; private set; }               // safety resets (NaN / too far) — should stay 0
+
+	private readonly Arm[] _arms = { new(), new() };
+	private readonly List<RigidBody3D> _bodies = new();
+	private Ball _spine, _neck;
+	private Vector3 _neckBaseToEye;                       // head frame, canonical (neck straight)
+	private float _trunk, _lumbar, _neckLen;
+	private Vector3 _eyeLocal;
+	private Vector3 _pelvisCenterLocal, _chestCenterLocal, _headCenterLocal; // from each body's proximal joint, in its basis
+	private readonly Dictionary<RigidBody3D, Transform3D> _targets = new();
+	private readonly Vector3[] _girdle = new Vector3[2];  // True Body shoulder offset, chest frame
+	private float _footY;
+	private float _supportGoalY;
+	private RigidBody3D _groundBody;
+	private Vector3 _groundPoint;
+	private float _tuckFree, _dt;
+	private PhysicsShapeQueryParameters3D _legsQuery;
+
+	private bool LegsSpaceFree(Vector3 center, Basis basis)
+	{
+		_legsQuery ??= new PhysicsShapeQueryParameters3D { Shape = Legs.GetChild<CollisionShape3D>(0).Shape, CollisionMask = WorldMask };
+		_legsQuery.Transform = new Transform3D(basis, center);
+		return GetWorld3D().DirectSpaceState.IntersectShape(_legsQuery, 1).Count == 0;
+	}
+	private Vector3 _goalVelocity;
+	private enum JumpPhase { None, Dip, Push, Flight }
+	private JumpPhase _jump;
+	private float _jumpT, _jumpRequest, _airT, _jumpFromY, _sinceLanding = float.MaxValue;
+
+	// Right A. Buffered, so a press just before touchdown still jumps.
+	public void Jump() => _jumpRequest = JumpBuffer;
+
+	private float _standingHip;   // hips of the standing pose above the feet = the legs' full extension
+
+	private static float LowPass(float dt, float tau) => 1f - Mathf.Exp(-dt / tau);
+	private bool _lifted;
+	private float _legsHeight;
+	private Drive _legsDrive;
+	private bool _legsSolid = true;
+	private ProceduralLegs _legVisuals;
+	private float _appliedStrength = 1f;
+	private Vector3 _pelvisTargetPrev;
+	private bool _havePelvisPrev;
+
+	public RigidBody3D Hand(int side) => Built ? _arms[side].Hand : null;
+	public RigidBody3D UpperArm(int side) => Built ? _arms[side].Upper : null;
+	public RigidBody3D Forearm(int side) => Built ? _arms[side].Fore : null;
+	public IReadOnlyList<RigidBody3D> Bodies => _bodies;
+
+	// ---------------------------------------------------------------- build
+
+	public void Build(BodyProfile p, TrueBodySolver pose, Transform3D left, Transform3D right)
+	{
+		Clear();
+		Profile = p;
+		_trunk = TrueBodySolver.TrunkRatio * p.Stature;
+		_lumbar = LumbarFraction * _trunk;
+		_neckLen = Mathf.Max(0.05f, p.ShoulderDrop + TrueBodySolver.EyeToNeckPivot.Y - TrueBodySolver.NeckBaseAboveShoulders);
+		float m = BodyMass;
+		float s = p.Stature / 1.75f;
+
+		// Canonical pose (standing, level head, arms straight down-forward-out) in frame C at the
+		// current pelvis: joint cones/twists are centred on it and the elbow hinge's zero is a
+		// straight arm. The body is then moved onto the live pose.
+		Transform3D c = new(pose.YawBasis, pose.PelvisTarget);
+		Vector3 hip = Vector3.Zero;
+		Vector3 lumbar = new(0f, _lumbar, 0f);
+		Vector3 upperChest = new(0f, _trunk, 0f);
+		Vector3 neckBase = upperChest + new Vector3(0f, TrueBodySolver.NeckBaseAboveShoulders,
+			-(TrueBodySolver.ShouldersBehindEyes - TrueBodySolver.EyeToNeckPivot.Z));
+		Vector3 neckPivot = neckBase + new Vector3(0f, _neckLen, 0f);
+		_eyeLocal = -TrueBodySolver.EyeToNeckPivot;   // head body origin is set to its centre below
+		Vector3 headCenterFromPivot = _eyeLocal + HeadCenterFromEye;
+
+		Vector3 pelvisSize = new(0.17f * p.Stature, _lumbar + 0.06f, 0.18f * s);
+		_pelvisCenterLocal = new Vector3(0f, _lumbar * 0.5f - 0.03f, 0f);
+		float chestHeight = _trunk - _lumbar + TrueBodySolver.NeckBaseAboveShoulders;
+		Vector3 chestSize = new(2f * p.ShoulderHalfWidth * 0.75f, chestHeight, 0.2f * s);
+		_chestCenterLocal = new Vector3(0f, chestHeight * 0.5f, 0f);
+		_headCenterLocal = headCenterFromPivot;
+		_eyeLocal -= headCenterFromPivot;             // eye relative to the head body's centre
+
+		Color skin = new(0.85f, 0.72f, 0.6f), shirt = new(0.3f, 0.45f, 0.7f), pants = new(0.25f, 0.27f, 0.32f);
+		Pelvis = MakeBody("Pelvis", new BoxShape3D { Size = pelvisSize }, (0.142f + 0.139f + 0.322f) * m - LegsMass, BodyLayer, WorldMask, pants,
+			c * new Transform3D(Basis.Identity, hip + _pelvisCenterLocal), friction: TorsoFriction);
+		float standingHip = pose.PelvisTarget.Y - (pose.Eye.Y - p.EyeHeight);
+		_standingHip = standingHip + _pelvisCenterLocal.Y;   // of the pelvis BODY (what ground control holds)
+		_legsHeight = Mathf.Max(0.2f, standingHip - MaxStepHeight);
+		Legs = MakeBody("Legs", new BoxShape3D { Size = new Vector3(0.28f * s, _legsHeight, 0.2f * s) }, LegsMass, BodyLayer, WorldMask, pants,
+			c * new Transform3D(Basis.Identity, hip - new Vector3(0f, _legsHeight * 0.5f, 0f)), visible: false);
+		// Explicit inertia: the collider is switched off when tucked, and a body without an
+		// enabled shape has no inertia — its 400 N·m drive then tumbled the whole pelvis
+		// (owner 2.1 "body spinning" when crouched).
+		Legs.Inertia = new Vector3(_legsHeight * _legsHeight + 0.04f, 0.28f * 0.28f + 0.04f, _legsHeight * _legsHeight + 0.08f) * (LegsMass / 12f);
+		_footY = pose.Eye.Y - p.EyeHeight;
+		Chest = MakeBody("Chest", new BoxShape3D { Size = chestSize }, 0.216f * m, BodyLayer, WorldMask, shirt,
+			c * new Transform3D(Basis.Identity, lumbar + _chestCenterLocal), friction: TorsoFriction);
+		Head = MakeBody("Head", new BoxShape3D { Size = HeadSize * s }, 0.081f * m, BodyLayer, WorldMask, skin,
+			c * new Transform3D(Basis.Identity, neckPivot + headCenterFromPivot), friction: TorsoFriction);
+		// The neck: a box hanging under the head, same body.
+		Vector3 neckCenter = (neckBase + neckPivot) * 0.5f - (neckPivot + headCenterFromPivot);
+		Head.AddChild(new CollisionShape3D { Shape = new BoxShape3D { Size = new Vector3(0.09f * s, _neckLen, 0.09f * s) }, Position = neckCenter });
+		MeshInstance3D neckMesh = new() { Mesh = new BoxMesh { Size = new Vector3(0.09f * s, _neckLen, 0.09f * s) }, Position = neckCenter };
+		neckMesh.SetSurfaceOverrideMaterial(0, new StandardMaterial3D { AlbedoColor = skin, Roughness = 0.6f });
+		Head.AddChild(neckMesh);
+		_neckBaseToEye = neckPivot - TrueBodySolver.EyeToNeckPivot - neckBase;
+
+		// World anchor for the balance motor (no shape, linear motor force 0 = position free).
+		StaticBody3D anchor = new() { Name = "BalanceAnchor", CollisionLayer = 0, CollisionMask = 0 };
+		AddChild(anchor);
+		_balance = MakeDrive(anchor, Pelvis, Pelvis.GlobalTransform, 0f, BalanceTorque);
+		_legsDrive = MakeDrive(Pelvis, Legs, c * new Transform3D(Basis.Identity, hip), LegsForce, LegsTorque);
+		_legVisuals = new ProceduralLegs { Name = "LegVisuals" };
+		AddChild(_legVisuals);
+		_legVisuals.Setup(Pelvis, -_pelvisCenterLocal, p.Stature, pants, new Color(0.15f, 0.15f, 0.17f));
+		_balanceCap = BalanceTorque;
+
+		_spine = MakeBall(Pelvis, Chest, c * lumbar, c.Basis * TwistAlong(Vector3.Up), Mathf.DegToRad(60f), Mathf.DegToRad(35f), SpineKp, SpineTorque);
+		_neck = MakeBall(Chest, Head, c * neckBase, c.Basis * TwistAlong(Vector3.Up), Mathf.DegToRad(75f), Mathf.DegToRad(85f), NeckKp, NeckTorque);
+
+		for (int side = 0; side < 2; side++)
+		{
+			Arm a = _arms[side];
+			float sign = side == 0 ? -1f : 1f;
+			a.UpperLen = p.UpperArm;
+			a.ForeLen = p.Forearm;
+			Vector3 shoulder = upperChest + new Vector3(sign * p.ShoulderHalfWidth, 0f, 0f);
+			Vector3 dir = new Vector3(sign * 0.42f, -0.74f, -0.47f).Normalized();
+			Vector3 reference = Vector3.Down * 2f + Vector3.Back * 0.8f + new Vector3(sign * 0.3f, 0f, 0f);
+			Vector3 pole = (reference - dir * reference.Dot(dir)).Normalized();
+			Vector3 hinge = pole.Cross(dir).Normalized();
+			Basis bone = BoneBasis(dir, hinge);
+			Vector3 elbow = shoulder + dir * a.UpperLen;
+			Vector3 wrist = elbow + dir * a.ForeLen;
+			Vector3 handX = (Vector3.Right - dir * dir.X).Normalized();
+			Basis handBasis = new(handX, (-dir).Cross(handX), -dir);
+			Vector3 handOrigin = wrist + dir * WristOffset;
+			string n = side == 0 ? "Left" : "Right";
+
+			a.Upper = MakeBody(n + "UpperArm", new BoxShape3D { Size = new Vector3(0.085f * s, a.UpperLen, 0.085f * s) }, 0.028f * m, ArmLayer, WorldMask, shirt,
+				c * new Transform3D(bone, shoulder + dir * (a.UpperLen * 0.5f)), friction: LimbFriction);
+			a.Fore = MakeBody(n + "Forearm", new BoxShape3D { Size = new Vector3(0.07f * s, a.ForeLen - 0.01f, 0.07f * s) }, 0.016f * m, ArmLayer, WorldMask, skin,
+				c * new Transform3D(bone, elbow + dir * (a.ForeLen * 0.5f)), friction: LimbFriction);
+			a.Hand = MakeBody(n + "Hand", new BoxShape3D { Size = HandSize }, 0.006f * m, HandLayer, WorldMask | HandLayer,
+				side == 0 ? new Color(0.9f, 0.3f, 0.35f) : new Color(0.3f, 0.5f, 0.9f), c * new Transform3D(handBasis, handOrigin), friction: LimbFriction);
+			a.Hand.ContinuousCd = true;
+			a.Hand.ContactMonitor = true;
+			a.Hand.MaxContactsReported = 8;
+
+			a.Shoulder = MakeDrive(Chest, a.Upper, c * new Transform3D(Basis.Identity, shoulder), GirdleForce, ShoulderTorque);
+			a.Elbow = MakeHinge(a.Upper, a.Fore, c * elbow, c.Basis * new Basis(dir, hinge.Cross(dir), hinge));
+			a.Wrist = MakeBall(a.Fore, a.Hand, c * wrist, c.Basis * TwistAlong(dir), Mathf.DegToRad(80f), Mathf.DegToRad(90f), 0f, 0f);
+			a.Guide = MakeDrive(Chest, a.Hand, c * new Transform3D(handBasis, handOrigin), HandGuideForce, HandGuideTorque);
+		}
+
+		Built = true;
+		_havePelvisPrev = false;
+		_appliedStrength = 1f;
+		_legsSolid = true;
+		ApplyStrength();
+		SnapToPose(pose, left, right);
+		GD.Print($"PlayerRagdoll: built for stature {p.Stature:F2} m (arm {p.UpperArm:F3}+{p.Forearm:F3} m, {_bodies.Count} bodies)");
+	}
+
+	public void Clear()
+	{
+		foreach (Node child in GetChildren())
+			child.QueueFree();
+		foreach (Node child in GetChildren())
+			RemoveChild(child);
+		_bodies.Clear();
+		_targets.Clear();
+		for (int i = 0; i < 2; i++)
+			_arms[i] = new Arm();
+		Built = false;
+		_jump = JumpPhase.None;
+		_jumpRequest = 0f;
+		_sinceLanding = float.MaxValue;
+	}
+
+	// Twist axis (joint X) along `dir`.
+	private static Basis TwistAlong(Vector3 dir)
+	{
+		Vector3 helper = Mathf.Abs(dir.Y) < 0.9f ? Vector3.Up : Vector3.Right;
+		Vector3 z = dir.Cross(helper).Normalized();
+		return new Basis(dir, z.Cross(dir), z);
+	}
+
+	// Segment basis: Y along the bone, X = elbow hinge axis.
+	private static Basis BoneBasis(Vector3 boneDir, Vector3 hinge)
+	{
+		Vector3 x = (hinge - boneDir * hinge.Dot(boneDir)).Normalized();
+		return new Basis(x, boneDir, x.Cross(boneDir));
+	}
+
+	// NOTE (Box3D wrapper): friction is read only when the body's shapes are created — the material
+	// must be set before AddChild (setting it later silently does nothing).
+	private RigidBody3D MakeBody(string name, Shape3D shape, float mass, uint layer, uint mask, Color color, Transform3D at, bool visible = true, float friction = 1f)
+	{
+		RigidBody3D body = new() { Name = name, Mass = mass, CollisionLayer = layer, CollisionMask = mask, Transform = at, ContactMonitor = true, MaxContactsReported = 4,
+			PhysicsMaterialOverride = new PhysicsMaterial { Friction = friction } };
+		body.AddChild(new CollisionShape3D { Shape = shape });
+		if (shape is BoxShape3D box && layer != 0 && visible)
+		{
+			MeshInstance3D mesh = new() { Mesh = new BoxMesh { Size = box.Size } };
+			mesh.SetSurfaceOverrideMaterial(0, new StandardMaterial3D { AlbedoColor = color, Roughness = 0.6f });
+			body.AddChild(mesh);
+		}
+		AddChild(body);
+		_bodies.Add(body);
+		return body;
+	}
+
+	private static Quaternion Rot(Node3D n) => n.GlobalTransform.Basis.Orthonormalized().GetRotationQuaternion();
+
+	// Configure BEFORE AddChild (the node pushes everything to the server on enter-tree).
+	private Ball MakeBall(RigidBody3D parent, RigidBody3D child, Vector3 at, Basis frame, float cone, float twist, float kp, float torque)
+	{
+		Generic6DofJoint3D j = new() { Transform = new Transform3D(frame, at), NodeA = parent.GetPath(), NodeB = child.GetPath(), ExcludeNodesFromCollision = true };
+		j.SetParamX(Generic6DofJoint3D.Param.AngularLowerLimit, -twist);
+		j.SetParamX(Generic6DofJoint3D.Param.AngularUpperLimit, twist);
+		foreach (var set in new System.Action<Generic6DofJoint3D.Param, float>[] { j.SetParamY, j.SetParamZ })
+		{
+			set(Generic6DofJoint3D.Param.AngularLowerLimit, -cone);
+			set(Generic6DofJoint3D.Param.AngularUpperLimit, cone);
+		}
+		if (torque > 0f)
+		{
+			j.SetFlagX(Generic6DofJoint3D.Flag.EnableMotor, true);
+			j.SetFlagY(Generic6DofJoint3D.Flag.EnableMotor, true);
+			j.SetFlagZ(Generic6DofJoint3D.Flag.EnableMotor, true);
+			j.SetParamX(Generic6DofJoint3D.Param.AngularMotorForceLimit, torque);
+			j.SetParamY(Generic6DofJoint3D.Param.AngularMotorForceLimit, torque);
+			j.SetParamZ(Generic6DofJoint3D.Param.AngularMotorForceLimit, torque);
+		}
+		AddChild(j);
+		Quaternion jq = frame.Orthonormalized().GetRotationQuaternion();
+		return new Ball { Joint = j, Parent = parent, Child = child, FrameA = Rot(parent).Inverse() * jq, FrameB = Rot(child).Inverse() * jq, Kp = kp };
+	}
+
+	private Drive MakeDrive(PhysicsBody3D parent, RigidBody3D child, Transform3D at, float force, float torque)
+	{
+		Generic6DofJoint3D j = new() { Transform = at, NodeA = parent.GetPath(), NodeB = child.GetPath(), ExcludeNodesFromCollision = true };
+		foreach (var flag in new System.Action<Generic6DofJoint3D.Flag, bool>[] { j.SetFlagX, j.SetFlagY, j.SetFlagZ })
+		{
+			flag(Generic6DofJoint3D.Flag.EnableLinearLimit, false);
+			flag(Generic6DofJoint3D.Flag.EnableAngularLimit, false);
+			flag(Generic6DofJoint3D.Flag.EnableLinearMotor, true);
+			flag(Generic6DofJoint3D.Flag.EnableMotor, true);
+		}
+		foreach (var param in new System.Action<Generic6DofJoint3D.Param, float>[] { j.SetParamX, j.SetParamY, j.SetParamZ })
+		{
+			param(Generic6DofJoint3D.Param.LinearMotorForceLimit, force);
+			param(Generic6DofJoint3D.Param.AngularMotorForceLimit, torque);
+		}
+		AddChild(j);
+		Quaternion jq = at.Basis.Orthonormalized().GetRotationQuaternion();
+		return new Drive
+		{
+			Joint = j,
+			FrameA = Rot(parent).Inverse() * jq,
+			FrameB = Rot(child).Inverse() * jq,
+			AnchorA = parent.GlobalTransform.AffineInverse() * at.Origin,
+			AnchorB = child.GlobalTransform.AffineInverse() * at.Origin,
+		};
+	}
+
+	private HingeJoint3D MakeHinge(RigidBody3D parent, RigidBody3D child, Vector3 at, Basis frame)
+	{
+		HingeJoint3D j = new() { Transform = new Transform3D(frame, at), NodeA = parent.GetPath(), NodeB = child.GetPath(), ExcludeNodesFromCollision = true };
+		float lo = HingeSign > 0f ? 0f : -ElbowMaxFlex;
+		float hi = HingeSign > 0f ? ElbowMaxFlex : 0f;
+		j.SetFlag(HingeJoint3D.Flag.UseLimit, true);
+		j.SetParam(HingeJoint3D.Param.LimitLower, lo);
+		j.SetParam(HingeJoint3D.Param.LimitUpper, hi);
+		j.SetFlag(HingeJoint3D.Flag.EnableMotor, true);
+		j.SetParam(HingeJoint3D.Param.MotorMaxImpulse, ElbowTorque);
+		AddChild(j);
+		return j;
+	}
+
+	// ---------------------------------------------------------------- pose targets
+
+	// World transform every body should have in the True Body pose. The trunk is rebuilt top-down
+	// through the physical chain (upper chest → lumbar → hips) so a leaning chest doesn't drag
+	// the head off the camera; the hips take part of the crouch lean (hip hinge).
+	private void ComputeTargets(TrueBodySolver s, Transform3D left, Transform3D right, bool physicalArms = false, float dt = 0f)
+	{
+		Basis chest = s.ChestBasis;
+		// Hips take half of a crouch lean, all of it in a crawl (keeps them off the floor).
+		float share = Mathf.Lerp(PelvisLeanShare, 1f, Mathf.Clamp((s.Lean - TrueBodySolver.ChestLeanMax) / 0.5f, 0f, 1f));
+		Basis pelvis = s.YawBasis * new Basis(Vector3.Right, -s.Lean * share);
+		Vector3 lumbar = s.UpperChest - chest.Y * (_trunk - _lumbar);
+		Vector3 hip = lumbar - pelvis.Y * _lumbar;
+		_targets[Pelvis] = new Transform3D(pelvis, hip + pelvis * _pelvisCenterLocal);
+		_targets[Chest] = new Transform3D(chest, lumbar + chest * _chestCenterLocal);
+		_targets[Legs] = new Transform3D(s.YawBasis, hip - Vector3.Up * (_legsHeight * 0.5f));  // snap pose only; LegsDrive steps it
+		// Head + neck pivot at the neck base: orient like the camera, tilted by the small extra
+		// rotation that puts the body's eye on the camera (the True Body bends the neck at two points).
+		Vector3 eyeDir = s.HeadBasis * _neckBaseToEye;
+		Vector3 wantDir = s.Eye - s.NeckBase;
+		Quaternion tilt = eyeDir.LengthSquared() > 1e-8f && wantDir.LengthSquared() > 1e-8f
+			? new Quaternion(eyeDir.Normalized(), wantDir.Normalized()) : Quaternion.Identity;
+		Basis head = new Basis(tilt) * s.HeadBasis;
+		_targets[Head] = new Transform3D(head, s.NeckBase + head * (_neckBaseToEye - _eyeLocal));
+
+		for (int side = 0; side < 2; side++)
+		{
+			Arm a = _arms[side];
+			Vector3 sh = s.Shoulder[side], el = s.Elbow[side], wr = s.Wrist[side];
+			Vector3 armDir = wr - sh;
+			armDir = armDir.LengthSquared() > 1e-8f ? armDir.Normalized() : chest * Vector3.Down;
+			Vector3 hinge = s.Pole[side].Cross(armDir);
+			hinge = hinge.LengthSquared() > 1e-8f ? hinge.Normalized() : chest.X;
+			Vector3 up = (el - sh).Normalized();
+			Vector3 fore = (wr - el).Normalized();
+			_girdle[side] = chest.Transposed() * (sh - (s.UpperChest + chest.X * ((side == 0 ? -1f : 1f) * Profile.ShoulderHalfWidth)));
+			_targets[a.Upper] = new Transform3D(BoneBasis(up, hinge), sh + up * (a.UpperLen * 0.5f));
+			_targets[a.Fore] = new Transform3D(BoneBasis(fore, hinge), el + fore * (a.ForeLen * 0.5f));
+			_targets[a.Hand] = (side == 0 ? left : right).Orthonormalized();
+
+			if (physicalArms)
+			{
+				// Re-aim the arm from the PHYSICAL shoulder. Horizontally the body may be held away from
+				// the camera (pressed against a ledge, leaning over a table): the arm reaches for the
+				// real hand. Vertically a sagging body keeps its arm pose (the aim point moves with
+				// the shoulder), so straight real arms stay straight virtual arms — pillars that hold
+				// you up when crawling or press you up a ledge (the hand guide adds the rest).
+				// Only a horizontal TRANSLATION of the reach: solved in the chest TARGET frame (the
+				// muscles stay local). Aiming in the physical chest frame made the shoulder muscles
+				// feed chest rotation back into the chest — a slow twist that tracking jitter
+				// excited into "chest slipping out of control" (owner playtest 2.1).
+				Transform3D chestPhys = Chest.GlobalTransform.Orthonormalized();
+				Vector3 shPhys = chestPhys * (a.Shoulder.AnchorA + _girdle[side]);
+				Vector3 held = shPhys - sh;
+				held.Y = 0f;
+				Transform3D ctrl = _targets[a.Hand];
+				ArmSolver solver = _armSolvers[side];
+				solver.Solve(sh, ctrl * new Vector3(0f, 0f, WristOffset) - held, chest, chest.X * (side == 0 ? -1f : 1f),
+					ctrl.Basis, a.UpperLen, a.ForeLen, dt);
+				Vector3 d = solver.Wrist - sh;
+				Vector3 h = d.LengthSquared() > 1e-8f ? solver.Pole.Cross(d.Normalized()) : chest.X;
+				h = h.LengthSquared() > 1e-8f ? h.Normalized() : chest.X;
+				Vector3 u = (solver.Elbow - sh).Normalized(), f = (solver.Wrist - solver.Elbow).Normalized();
+				_targets[a.Upper] = new Transform3D(BoneBasis(u, h), sh + u * (a.UpperLen * 0.5f));
+				_targets[a.Fore] = new Transform3D(BoneBasis(f, h), solver.Elbow + f * (a.ForeLen * 0.5f));
+			}
+		}
+	}
+
+	private readonly ArmSolver[] _armSolvers = { new(), new() };
+
+	public Transform3D Target(RigidBody3D body) => _targets.TryGetValue(body, out Transform3D t) ? t : body.GlobalTransform;
+
+	// ---------------------------------------------------------------- per tick
+
+	public void Step(TrueBodySolver s, Transform3D left, Transform3D right, Vector3 leftVelocity, Vector3 rightVelocity, float floorY, float dt)
+	{
+		if (!Built)
+			return;
+		_dt = dt;
+		_floorYForHead = floorY;
+		ComputeTargets(s, left, right, physicalArms: true, dt);
+		foreach (RigidBody3D b in _bodies)
+		{
+			if (BodyMath.ResetIfNonFinite(b, Target(b), "PlayerRagdoll"))
+			{
+				Snaps++;
+				SnapToPose(s, left, right);
+				return;
+			}
+		}
+
+		Transform3D pelvisTarget = _targets[Pelvis];
+		if (Pelvis.GlobalPosition.DistanceTo(pelvisTarget.Origin) > ResetDistance)
+		{
+			GD.Print("PlayerRagdoll: body too far from the pose, snapped to it");
+			Snaps++;
+			SnapToPose(s, left, right);
+			return;
+		}
+
+		Muscle(_spine, _targets[Pelvis].Basis, _targets[Chest].Basis, dt);
+		Muscle(_neck, _targets[Chest].Basis, _targets[Head].Basis, dt);
+		if (Strength != _appliedStrength)
+			ApplyStrength();
+		Braced = false;
+		for (int side = 0; side < 2; side++)
+		{
+			Arm a = _arms[side];
+			ShoulderDrive(a, side, dt);
+			ElbowMuscle(a, dt);
+			HandGuide(a, _targets[a.Hand], side == 0 ? leftVelocity : rightVelocity);
+			Braced |= IsBraced(a);
+		}
+		GroundControl(pelvisTarget, floorY, dt);
+		HeadGuide(s, dt);
+		LegsDrive(s);
+		_legVisuals.Tick(_footY, Grounded, !_legsSolid, s.YawBasis, dt);
+	}
+
+	// Muscle = PD on the joint's relative rotation toward the relative rotation of the two TARGET
+	// bases (a local pose, not a world pin), written as the motor's target velocity in frame A.
+	// Feed-forward = the target's own relative spin, so a moving pose isn't chased with a lag of
+	// speed/Kp.
+	private static void Muscle(Ball b, Basis parentTarget, Basis childTarget, float dt)
+	{
+		Quaternion current = (Rot(b.Parent) * b.FrameA).Inverse() * (Rot(b.Child) * b.FrameB);
+		Quaternion target = (parentTarget.Orthonormalized().GetRotationQuaternion() * b.FrameA).Inverse()
+			* (childTarget.Orthonormalized().GetRotationQuaternion() * b.FrameB);
+		Vector3 raw = b.HasPrev && dt > 0f ? (BodyMath.RotationError(target, b.PrevTarget) / dt).LimitLength(MuscleMaxSpin) : Vector3.Zero;
+		b.Ff = b.Ff.Lerp(raw, LowPass(dt, MuscleFeedForwardTau));
+		b.PrevTarget = target;
+		b.HasPrev = true;
+		Vector3 w = (b.Ff + BodyMath.RotationError(target, current) * b.Kp).LimitLength(MuscleMaxSpin);
+		SetAngularVelocity(b.Joint, w);
+	}
+
+	private static void SetAngularVelocity(Generic6DofJoint3D j, Vector3 w)
+	{
+		j.SetParamX(Generic6DofJoint3D.Param.AngularMotorTargetVelocity, w.X);
+		j.SetParamY(Generic6DofJoint3D.Param.AngularMotorTargetVelocity, w.Y);
+		j.SetParamZ(Generic6DofJoint3D.Param.AngularMotorTargetVelocity, w.Z);
+	}
+
+	private static void SetLinearVelocity(Generic6DofJoint3D j, Vector3 v)
+	{
+		j.SetParamX(Generic6DofJoint3D.Param.LinearMotorTargetVelocity, v.X);
+		j.SetParamY(Generic6DofJoint3D.Param.LinearMotorTargetVelocity, v.Y);
+		j.SetParamZ(Generic6DofJoint3D.Param.LinearMotorTargetVelocity, v.Z);
+	}
+
+	// Elbow flexion (0 = straight) about the upper arm's hinge axis.
+	public float ElbowFlex(int side)
+	{
+		Arm a = _arms[side];
+		Basis u = a.Upper.GlobalTransform.Basis.Orthonormalized();
+		Vector3 f = a.Fore.GlobalTransform.Basis.Orthonormalized().Y;
+		return Mathf.Atan2(u.X.Dot(u.Y.Cross(f)), u.Y.Dot(f));
+	}
+
+	private void ElbowMuscle(Arm a, float dt)
+	{
+		int side = a == _arms[0] ? 0 : 1;
+		Vector3 up = _targets[a.Upper].Basis.Y, fore = _targets[a.Fore].Basis.Y;
+		float target = Mathf.Acos(Mathf.Clamp(up.Dot(fore), -1f, 1f));
+		float raw = a.PrevFlexTarget >= 0f && dt > 0f ? Mathf.Clamp((target - a.PrevFlexTarget) / dt, -MuscleMaxSpin, MuscleMaxSpin) : 0f;
+		a.FlexFf = Mathf.Lerp(a.FlexFf, raw, LowPass(dt, MuscleFeedForwardTau));
+		a.PrevFlexTarget = target;
+		float w = Mathf.Clamp(a.FlexFf + (target - ElbowFlex(side)) * ElbowKp, -MuscleMaxSpin, MuscleMaxSpin);
+		a.Elbow.SetParam(HingeJoint3D.Param.MotorTargetVelocity, HingeSign * w);
+		float cap = (w > 0f ? ElbowFlexTorque : ElbowTorque) * Mathf.Max(0.05f, Strength);
+		if (Mathf.Abs(cap - a.ElbowCap) > 0.5f)
+		{
+			a.ElbowCap = cap;
+			a.Elbow.SetParam(HingeJoint3D.Param.MotorMaxImpulse, cap);
+		}
+	}
+
+	// Head guide (Boneworks/BIMOS drive the head to the HMD): while standing on the ground, a force-
+	// capped PD pulls the character's eye onto the camera, so voluntary head motion (squats, leans,
+	// quick looks) doesn't leave the body lagging — a lag the riding view would otherwise turn into
+	// a permanent play-space offset. Off while airborne/climbing (no levitating by the head) or
+	// bracing on the hands (mantling, pushing off).
+	private void HeadGuide(TrueBodySolver s, float dt)
+	{
+		Vector3 goal = s.Eye + Vector3.Up * (_footY - _floorYForHead);
+		Vector3 raw = _haveHeadPrev && dt > 0f ? (goal - _headGoalPrev) / dt : Vector3.Zero;
+		_headGoalPrev = goal;
+		_haveHeadPrev = true;
+		if (raw.Length() > 10f)
+			raw = Vector3.Zero;
+		_headGoalVelocity = _headGoalVelocity.Lerp(raw, LowPass(dt, GroundFeedForwardTau));
+		// Only on your feet: hands bracing (mantling, pushing yourself) or crawling move the body by
+		// other means, and the view simply follows it.
+		if (!Grounded || Climbing || Braced || _jump != JumpPhase.None || _sinceLanding < AbsorbTime)
+			return;
+		float w = Mathf.Tau * HeadGuideFrequency;
+		Vector3 force = ((goal - Eye) * (w * w) + (_headGoalVelocity - Head.LinearVelocity) * (2f * w)) * HeadGuideMass;
+		Head.ApplyCentralForce(force.LimitLength(HeadGuideForce));
+	}
+
+	private Vector3 _headGoalPrev, _headGoalVelocity;
+	private bool _haveHeadPrev;
+	private float _floorYForHead;
+
+	private void ApplyStrength()
+	{
+		_appliedStrength = Strength;
+		float k = Mathf.Max(0.05f, Strength);
+		SetAngularCap(_spine.Joint, SpineTorque * k);
+		SetAngularCap(_neck.Joint, NeckTorque * k);
+		foreach (Arm a in _arms)
+		{
+			SetAngularCap(a.Shoulder.Joint, ShoulderTorque * k);
+			a.ShoulderCap = ShoulderTorque * k;
+			a.ElbowCap = ElbowTorque * k;
+			SetAngularCap(a.Guide.Joint, HandGuideTorque * k);
+			a.Elbow.SetParam(HingeJoint3D.Param.MotorMaxImpulse, ElbowTorque * k);
+		}
+	}
+
+	private static void SetAngularCap(Generic6DofJoint3D j, float cap)
+	{
+		j.SetParamX(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
+		j.SetParamY(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
+		j.SetParamZ(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
+	}
+
+	private static void SetLinearCap(Generic6DofJoint3D j, float cap)
+	{
+		j.SetParamX(Generic6DofJoint3D.Param.LinearMotorForceLimit, cap);
+		j.SetParamY(Generic6DofJoint3D.Param.LinearMotorForceLimit, cap);
+		j.SetParamZ(Generic6DofJoint3D.Param.LinearMotorForceLimit, cap);
+	}
+
+	// A hand pressing on or holding static world (a ledge, a wall, a grabbed bar) — not the floor:
+	// hands on the floor while crawling don't lift the body.
+	private static bool IsBraced(Arm a)
+	{
+		if (a.Held is StaticBody3D)
+			return true;
+		foreach (Node3D n in a.Hand.GetCollidingBodies())
+			if (n is StaticBody3D && !n.IsInGroup(PropGrabber.NoGrabGroup))
+				return true;
+		return false;
+	}
+
+	// The lower-body collider hangs from the actual hips, its bottom never below a step above the
+	// feet; once it would have to slide far up into the torso (deep crouch, crawl) it stops colliding.
+	private void LegsDrive(TrueBodySolver s)
+	{
+		Transform3D pelvis = Pelvis.GlobalTransform;
+		Vector3 hip = pelvis * (-_pelvisCenterLocal);
+		float minCenter = _footY + MaxStepHeight + _legsHeight * 0.5f;
+		float center = Mathf.Max(hip.Y - _legsHeight * 0.5f, minCenter);
+		// Tuck (collider off, folded into the pelvis): deep crouch/crawl, or the hands bracing to
+		// lift the body (mantle, climbing — the knees come up). It STAYS tucked until it has been
+		// unneeded for a while AND its untucked spot is free: re-enabling inside a ledge face is
+		// what shoved the body off again and again (owner 2.2 "legs trying to get off the
+		// ground and instantly coming back").
+		bool climbingHold = _arms[0].Held is StaticBody3D || _arms[1].Held is StaticBody3D;
+		_lifted = Braced && (Pelvis.GlobalPosition.Y > _supportGoalY + MantleLift || climbingHold);
+		bool deep = center + _legsHeight * 0.5f >= hip.Y + LegsOffAbove;
+		bool wantTuck = deep || _lifted || (!_legsSolid && Braced);
+		_tuckFree = wantTuck ? 0f : _tuckFree + _dt;
+		Vector3 untucked = new(hip.X, center, hip.Z);
+		bool solid = _legsSolid ? !wantTuck : _tuckFree > UntuckDelay && LegsSpaceFree(untucked, s.YawBasis);
+		if (solid != _legsSolid)
+		{
+			_legsSolid = solid;
+			// The shape itself is disabled: Box3D keeps existing contacts when only the layer changes.
+			Legs.GetChild<CollisionShape3D>(0).SetDeferred(CollisionShape3D.PropertyName.Disabled, !solid);
+		}
+		if (!solid)
+			center = hip.Y;   // tucked into the pelvis, out of the way
+		Vector3 desired = new(hip.X, center, hip.Z);
+		Quaternion frameA = Rot(Pelvis) * _legsDrive.FrameA;
+		// Speed-limited: the legs dropping back out of the tuck at full drive speed kicked the pelvis
+		// up (the reaction) just as a landing dip was rising — a 5 cm bounce.
+		SetLinearVelocity(_legsDrive.Joint, frameA.Inverse() * ((desired - Legs.GlobalPosition) * LegsKp).LimitLength(LegsMaxSpeed));
+		Quaternion target = (Rot(Pelvis) * _legsDrive.FrameA).Inverse() * (s.YawBasis.GetRotationQuaternion() * _legsDrive.FrameB);
+		Quaternion current = frameA.Inverse() * (Rot(Legs) * _legsDrive.FrameB);
+		SetAngularVelocity(_legsDrive.Joint, (BodyMath.RotationError(target, current) * LegsKp).LimitLength(MuscleMaxSpin));
+	}
+
+	// Shoulder = one drive: its linear motor keeps the humeral head on the chest's shoulder point
+	// shifted by the True Body girdle offset (shrug/protraction), its angular motor is the
+	// shoulder muscle (same PD + feed-forward as Muscle, parent = chest).
+	private void ShoulderDrive(Arm a, int side, float dt)
+	{
+		Drive d = a.Shoulder;
+		Transform3D chest = Chest.GlobalTransform.Orthonormalized();
+		Vector3 desired = chest * (d.AnchorA + _girdle[side]);
+		Vector3 err = desired - a.Upper.GlobalTransform * d.AnchorB;
+		Quaternion frameA = chest.Basis.GetRotationQuaternion() * d.FrameA;
+		SetLinearVelocity(d.Joint, frameA.Inverse() * (err * GirdleKp));
+
+		Quaternion current = frameA.Inverse() * (Rot(a.Upper) * d.FrameB);
+		// Local muscle: relative to the chest's TARGET pose (never to the physical chest — that
+		// closes a rotation feedback loop through the arms).
+		Quaternion target = (_targets[Chest].Basis.Orthonormalized().GetRotationQuaternion() * d.FrameA).Inverse()
+			* (_targets[a.Upper].Basis.Orthonormalized().GetRotationQuaternion() * d.FrameB);
+		Vector3 raw = d.HasPrev && dt > 0f ? (BodyMath.RotationError(target, d.PrevTarget) / dt).LimitLength(MuscleMaxSpin) : Vector3.Zero;
+		d.Ff = d.Ff.Lerp(raw, LowPass(dt, MuscleFeedForwardTau));
+		d.PrevTarget = target;
+		d.HasPrev = true;
+		Vector3 spin = (d.Ff + BodyMath.RotationError(target, current) * ShoulderKp).LimitLength(MuscleMaxSpin);
+		SetAngularVelocity(d.Joint, spin);
+		// Which way is the muscle moving the arm? Rotating the bone direction downward = pulling.
+		Vector3 bone = (a.Upper.GlobalTransform.Basis.Y).Normalized();
+		Vector3 boneMotion = (frameA * spin).Cross(bone);
+		float cap = (boneMotion.Y < 0f ? ShoulderPullTorque : ShoulderTorque) * Mathf.Max(0.05f, Strength);
+		if (Mathf.Abs(cap - a.ShoulderCap) > 0.5f)
+		{
+			a.ShoulderCap = cap;
+			SetAngularCap(d.Joint, cap);
+		}
+	}
+
+	// Force-capped pull of the hand onto the controller, reacting into the chest (arm muscles).
+	private void HandGuide(Arm a, Transform3D target, Vector3 targetVelocity)
+	{
+		Transform3D chest = Chest.GlobalTransform;
+		Vector3 anchor = chest * a.Guide.AnchorA;
+		Vector3 anchorVelocity = Chest.LinearVelocity + Chest.AngularVelocity.Cross(anchor - Chest.GlobalPosition);
+		Vector3 err = target.Origin - a.Hand.GlobalPosition;
+		Vector3 desired = (targetVelocity + err * HandGuideKp).LimitLength(HandGuideMaxSpeed);
+		Quaternion frameA = Rot(Chest) * a.Guide.FrameA;
+		Vector3 shoulder = a.Upper.GlobalTransform * a.Shoulder.AnchorB;
+		Vector3 axis = a.Hand.GlobalPosition - shoulder;
+		// Axial share of the error, with a 3 cm floor so a nearly-reached target's noisy error
+		// direction can't flip a held load into "structural".
+		// PUSH only (the hand wants to go further from the shoulder — straight arms pressing on a
+		// ledge): bone in compression. Pulling (shortening the arm: pull-ups, climbing) is muscle
+		// work — the asymmetric shoulder/elbow muscles do it, and one arm can't lift the body.
+		float align = axis.LengthSquared() > 1e-8f ? Mathf.Max(0f, err.Dot(axis.Normalized())) / (err.Length() + StructuralDeadband) : 0f;
+		// Structure only helps against something: a hand in free air reaching past its arm's
+		// length must not haul the whole body after it.
+		if (a.Held == null && a.Hand.GetContactCount() == 0)
+			align = 0f;
+		float cap = Mathf.Lerp(HandGuideForce, HandStructuralForce, align) * Mathf.Max(0.05f, Strength);
+		if (Mathf.Abs(cap - a.GuideCap) > 1f)
+		{
+			a.GuideCap = cap;
+			SetLinearCap(a.Guide.Joint, cap);
+		}
+		SetLinearVelocity(a.Guide.Joint, frameA.Inverse() * (desired - anchorVelocity));
+		// Angular: hand rotation onto the controller rotation, as a relative spin vs the chest.
+		Vector3 rotErr = BodyMath.RotationError(target.Basis.GetRotationQuaternion(), Rot(a.Hand));
+		Vector3 wWorld = (rotErr * HandGuideAngularKp).LimitLength(MuscleMaxSpin * 2f) - Chest.AngularVelocity;
+		SetAngularVelocity(a.Guide.Joint, frameA.Inverse() * wWorld);
+	}
+
+	// "Leg strength": a stiff, mass-scaled support holding the pelvis at its pose height above the
+	// ground and carrying it after the head horizontally (friction-limited), plus an upright/yaw
+	// balance motor (world anchor → pelvis). No ground → no support (falls); balance weakens in the air.
+	private void GroundControl(Transform3D target, float floorY, float dt)
+	{
+		Vector3 pos = Pelvis.GlobalPosition;
+		float hipAboveFloor = target.Origin.Y - floorY;
+		var query = PhysicsRayQueryParameters3D.Create(pos, pos + Vector3.Down * (hipAboveFloor + GroundProbeExtra + 0.5f), WorldMask);
+		Godot.Collections.Dictionary hit = GetWorld3D().DirectSpaceState.IntersectRay(query);
+		bool wasGrounded = Grounded;
+		Grounded = false;
+		_groundBody = null;
+		if (hit.Count > 0)
+		{
+			Vector3 point = (Vector3)hit["position"];
+			Vector3 normal = (Vector3)hit["normal"];
+			_groundBody = GodotObject.InstanceFromId((ulong)hit["collider_id"]) as RigidBody3D;  // Box3D: "collider" is null
+			_groundPoint = point;
+			// Standing (or walking down a step) the legs keep contact over GroundProbeExtra; falling,
+			// they touch down only within their reach — the rest of the fall is stopped by the legs.
+			float reach = wasGrounded && _jump != JumpPhase.Flight ? GroundProbeExtra : LandingReach;
+			bool inReach = pos.Y - point.Y < hipAboveFloor + reach;
+			bool steep = normal.Y <= Mathf.Cos(Mathf.DegToRad(MaxSlopeDegrees));
+			if (_jump == JumpPhase.Flight && Pelvis.LinearVelocity.Y > 0f)
+			{
+				// Still rising off the ground: nothing to stand on yet.
+			}
+			else if (inReach && steep && wasGrounded && point.Y <= _footY + MaxStepHeight)
+			{
+				// The foot of a too-steep slope: keep standing on the ground we're on (the legs
+				// collider stops us); dropping support here would collapse the body.
+				Grounded = true;
+			}
+			else if (inReach && !steep)
+			{
+				// Step rule: ground more than a step above the feet is only stood on once the
+				// hips are already well above it (climbed/mantled/landed there) — otherwise it's an
+				// obstacle the legs collider holds us back from, and the feet stay where they were.
+				// Higher ground climbed onto must be under the hips' back edge too (not just a
+				// pelvis centre hanging over the lip).
+				bool clear = point.Y <= _footY + MaxStepHeight || GroundBehindAt(pos, point.Y);
+				bool reachable = point.Y <= _footY + MaxStepHeight
+					|| ((!wasGrounded || _lifted || pos.Y - point.Y > 0.6f * hipAboveFloor) && clear);
+				Grounded = true;
+				if (reachable)
+					_footY = point.Y;
+			}
+		}
+
+		// Feed-forward from the GOAL (pose + ground offset): when the play-space floor follows the
+		// ground, the pose target and the ground offset move by the same amount in opposite
+		// directions — differentiating the pose alone would launch the body.
+		Vector3 goalNow = target.Origin + Vector3.Up * (_footY - floorY);
+		Vector3 rawVelocity = _havePelvisPrev && dt > 0f ? (goalNow - _pelvisTargetPrev) / dt : Vector3.Zero;
+		_pelvisTargetPrev = goalNow;
+		_havePelvisPrev = true;
+		if (rawVelocity.Length() > 10f)
+			rawVelocity = Vector3.Zero;
+		_goalVelocity = _goalVelocity.Lerp(rawVelocity, LowPass(dt, GroundFeedForwardTau));
+		// Held back = the hips can't get to where the pose wants them (knee-high box, table edge,
+		// wall). Measured at the hips, not the head: the body tips over an obstacle, so the head
+		// may be right where the camera is while the hips are stuck.
+		Vector3 hipLag = new(target.Origin.X - pos.X, 0f, target.Origin.Z - pos.Z);
+		HeldBack = Grounded && hipLag.Length() > FreeSlack ? hipLag.Normalized() : Vector3.Zero;
+		Vector3 targetVelocity = _goalVelocity;
+
+		float weight = BodyMass * 9.8f;
+		if (Grounded && !wasGrounded && Pelvis.LinearVelocity.Y < -1.5f)
+			_sinceLanding = 0f;
+		_sinceLanding += dt;
+		UpdateJump(dt, wasGrounded);
+		if (_jump == JumpPhase.Push)
+			Grounded = true;   // the feet push off the ground they were on (also over a just-left edge)
+		if (Grounded)
+		{
+			// Pose heights are relative to the tracking floor; stand on the ground actually under us.
+			Vector3 goal = target.Origin + Vector3.Up * (GroundY - floorY);
+			_supportGoalY = goal.Y;
+			if (_jump == JumpPhase.Dip)
+				goal.Y = Mathf.Min(goal.Y, _jumpFromY);
+			float w = Mathf.Tau * GroundFrequency;
+			Vector3 accel = (goal - pos) * (w * w) + (targetVelocity - Pelvis.LinearVelocity) * (2f * GroundDamping * w);
+			Vector3 force = accel * BodyMass;
+			// Vertical as a rate-limited velocity servo: full leg strength brakes a landing, but
+			// the legs raise the body at most MaxRiseSpeed — they can push, not pull, so a hard push
+			// toward a higher stance (onto a ledge) would otherwise overshoot into a jump.
+			// Rising, the legs can only stop the body by letting gravity do it (support ≥ 0): ease the
+			// rise so it can still be stopped at the stance with ~0.7 g, or it overshoots (a bounce).
+			float below = goal.Y - pos.Y;
+			float stoppable = below > 0f ? Mathf.Sqrt(2f * 0.7f * 9.8f * below) : 0f;
+			float riseVelocity = Mathf.Clamp(below * w, -3f, Mathf.Min(MaxRiseSpeed, stoppable)) + targetVelocity.Y;
+			float verticalAccel = (riseVelocity - Pelvis.LinearVelocity.Y) * (2f * GroundDamping * w);
+			float support = Mathf.Clamp(verticalAccel * BodyMass + weight, 0f, LegStrength * weight);
+			if (_jump == JumpPhase.Push)
+				support = JumpForce * weight;
+			float carry = Mathf.Max(GroundFriction * support, _legsSolid ? 0f : CrawlCarry);
+			// Hips held back by an obstacle: lean on it, don't bulldoze — full leg force tipped the
+			// body over knee-high boxes and steep slopes (and the riding view tipped with it).
+			if (HeldBack != Vector3.Zero)
+				carry = Mathf.Min(carry, BlockedPush);
+			Vector3 horizontal = new Vector3(force.X, 0f, force.Z).LimitLength(carry);
+			Pelvis.ApplyCentralForce(horizontal + Vector3.Up * support);
+			// Newton's third law: standing on something movable (seesaw, plank, crate) pushes it
+			// down — the feet aren't physical, so the reaction is applied where the ground ray hit.
+			if (_groundBody != null && IsInstanceValid(_groundBody))
+				_groundBody.ApplyForce(-(horizontal + Vector3.Up * support), _groundPoint - _groundBody.GlobalPosition);
+		}
+		else if (Braced)
+		{
+			// Hanging/mantling on the hands: the hips still drift after the head a little, so you can
+			// shift your weight over a ledge you're pressing yourself up onto.
+			Vector3 lead = target.Origin - pos;
+			lead.Y = 0f;
+			Vector3 v = Pelvis.LinearVelocity;
+			v.Y = 0f;
+			Pelvis.ApplyCentralForce(((lead * 20f - v * 8f) * BodyMass).LimitLength(BracedAirControl));
+		}
+
+		Vector3 rotErr = BodyMath.RotationError(target.Basis.GetRotationQuaternion(), Rot(Pelvis));
+		Vector3 spin = (rotErr * BalanceKp).LimitLength(MuscleMaxSpin);
+		SetAngularVelocity(_balance.Joint, _balance.FrameA.Inverse() * spin);  // anchor = world frame
+		float cap = BalanceTorque * (Grounded ? 1f : AirBalanceShare);
+		if (cap != _balanceCap)
+		{
+			_balanceCap = cap;
+			_balance.Joint.SetParamX(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
+			_balance.Joint.SetParamY(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
+			_balance.Joint.SetParamZ(Generic6DofJoint3D.Param.AngularMotorForceLimit, cap);
+		}
+	}
+
+	// Jump state: request → Dip (countermovement, the support goal drops) → Push (full leg force up to
+	// extension) → Flight (no ground until falling again) → None on touchdown.
+	private void UpdateJump(float dt, bool wasGrounded)
+	{
+		_airT = Grounded ? 0f : _airT + dt;
+		_jumpRequest -= dt;
+		_jumpT += dt;
+		float pos = Pelvis.GlobalPosition.Y;
+		float top = _footY + _standingHip + JumpExtension;
+		switch (_jump)
+		{
+			case JumpPhase.None:
+				if (_jumpRequest > 0f && (Grounded || _airT < CoyoteTime) && !Climbing)
+				{
+					_jumpRequest = 0f;
+					_jumpT = 0f;
+					// Stroke at least JumpDip + JumpExtension: from standing, dip first.
+					_jumpFromY = Mathf.Max(top - JumpMaxStroke, Mathf.Min(pos, top - JumpDip - JumpExtension));
+					_jump = pos > _jumpFromY + 0.02f && Grounded ? JumpPhase.Dip : JumpPhase.Push;
+					_jumpFromY = Mathf.Min(_jumpFromY, pos);
+				}
+				break;
+			case JumpPhase.Dip:
+				if (pos <= _jumpFromY + 0.02f || _jumpT > 0.2f || !Grounded)
+				{
+					_jump = JumpPhase.Push;
+					_jumpFromY = pos;
+					_jumpT = 0f;
+				}
+				break;
+			case JumpPhase.Push:
+				if (pos >= top || pos - _jumpFromY >= JumpMaxStroke || _jumpT > 0.35f)
+				{
+					_jump = JumpPhase.Flight;
+					_jumpT = 0f;
+				}
+				break;
+			case JumpPhase.Flight:
+				if (Grounded && _jumpT > 0.05f)
+					_jump = JumpPhase.None;
+				break;
+		}
+	}
+
+	private Drive _balance;
+	private float _balanceCap;
+
+	// ---------------------------------------------------------------- play space
+
+	// How the driver should move its play-space origin after the last physics step. ONE rule, always,
+	// in all directions (Boneworks/BIMOS: the rig rides the body): the camera rides the character's
+	// eye. Head motion leads the body by at most ViewDeadzone (eased) / MaxViewLead (hard) — less
+	// than the head box reaches in front of the eye, so the view stays inside the head. A sphere
+	// swept eye→camera snaps the view back at once when geometry is in the way.
+	// This does NOT feed back into the pose: the True Body reads the head relative to the play-space
+	// floor (crouch = local head height) and ground control re-bases its goal onto the real ground
+	// (footY − floorY), so moving the play space vertically changes neither. (2.3 split height off
+	// to a separate floor-follow out of fear of that loop; the two then fought over the same height,
+	// and landings left the view hanging above a sinking body — owner 2.4.)
+	public Vector3 OriginCorrection(Vector3 camera, float floorY, float dt)
+	{
+		if (!Built)
+			return Vector3.Zero;
+		Vector3 eye = Eye;
+		Vector3 lead = camera - eye;
+		Vector3 correction = Vector3.Zero;
+		if (lead.LengthSquared() > 1e-8f)
+		{
+			_cameraQuery ??= new PhysicsShapeQueryParameters3D { Shape = new SphereShape3D { Radius = CameraRadius }, CollisionMask = WorldMask };
+			_cameraQuery.Transform = new Transform3D(Basis.Identity, eye);
+			_cameraQuery.Motion = lead;
+			float[] fractions = GetWorld3D().DirectSpaceState.CastMotion(_cameraQuery);
+			float safe = fractions.Length > 0 ? fractions[0] : 1f;
+			if (safe < 1f)
+				correction = -lead * (1f - safe);
+			Vector3 rest = lead + correction;
+			if (rest.Length() > ViewDeadzone)
+				correction -= rest * (1f - ViewDeadzone / rest.Length()) * (1f - Mathf.Exp(-dt / ViewFollowTau));
+			rest = lead + correction;
+			if (rest.Length() > MaxViewLead)
+				correction -= rest * (1f - MaxViewLead / rest.Length());
+		}
+		// Slow re-centering of the play-space floor onto the real ground while standing: removes the
+		// small height offsets the riding view picks up (a transient lag, a landing). The pose and the
+		// head guide are re-based on the real ground, so this only brings the camera onto the eye —
+		// the same direction as the follow above, never against it.
+		if (Grounded)
+			correction.Y += (_footY - floorY) * (1f - Mathf.Exp(-dt / FloorRecenterTau));
+		// The pose target moves with the play space: a correction is not intended motion, so it
+		// must not show up in ground control's feed-forward (that loop ran away at 7 m/s).
+		// Horizontally only — vertically the goals are re-based on the real ground (− floorY), so
+		// they don't move with the play space; shifting them too turned the view riding a landing
+		// dip into a ~1 m/s upward feed-forward (a 15 cm bounce).
+		Vector3 flat = new(correction.X, 0f, correction.Z);
+		_pelvisTargetPrev += flat;
+		_headGoalPrev += flat;
+		return correction;
+	}
+
+	private PhysicsShapeQueryParameters3D _cameraQuery;
+
+	// Second ground ray 12 cm behind the hips (toward the body's back): ground at least `groundY`.
+	private bool GroundBehindAt(Vector3 pelvisPos, float groundY)
+	{
+		Vector3 back = Pelvis.GlobalTransform.Basis.Z;
+		back.Y = 0f;
+		back = back.LengthSquared() > 1e-6f ? back.Normalized() * 0.12f : Vector3.Zero;
+		var query = PhysicsRayQueryParameters3D.Create(pelvisPos + back, pelvisPos + back + Vector3.Down * 3f, WorldMask);
+		Godot.Collections.Dictionary hit = GetWorld3D().DirectSpaceState.IntersectRay(query);
+		return hit.Count > 0 && ((Vector3)hit["position"]).Y > groundY - 0.05f;
+	}
+
+	public void TeleportBy(Transform3D delta)
+	{
+		if (!Built)
+			return;
+		foreach (RigidBody3D b in _bodies)
+		{
+			b.GlobalTransform = delta * b.GlobalTransform;
+			b.LinearVelocity = delta.Basis * b.LinearVelocity;
+			b.AngularVelocity = delta.Basis * b.AngularVelocity;
+		}
+		_pelvisTargetPrev = delta * _pelvisTargetPrev;
+		_footY += delta.Origin.Y;
+		foreach (RigidBody3D b in _bodies)
+			b.ResetPhysicsInterpolation();
+	}
+
+	public void SnapToPose(TrueBodySolver s, Transform3D left, Transform3D right)
+	{
+		ComputeTargets(s, left, right);
+		foreach (RigidBody3D b in _bodies)
+		{
+			b.GlobalTransform = Target(b);
+			b.LinearVelocity = Vector3.Zero;
+			b.AngularVelocity = Vector3.Zero;
+		}
+		// The hands sit at the wrist end of the solved arm, not at a possibly unreachable controller.
+		for (int side = 0; side < 2; side++)
+		{
+			Arm a = _arms[side];
+			Basis hb = _targets[a.Hand].Basis;
+			a.Hand.GlobalTransform = new Transform3D(hb, s.Wrist[side] - hb * new Vector3(0f, 0f, WristOffset));
+		}
+		_havePelvisPrev = false;
+		foreach (RigidBody3D b in _bodies)
+			b.ResetPhysicsInterpolation();
+	}
+
+	// Collision exceptions between a held prop and that arm's segments (its hand is excluded by
+	// the grab weld itself) — a forearm wrapped around a held object must not fight it.
+	public void SetHeld(int side, PhysicsBody3D prop)
+	{
+		if (!Built)
+			return;
+		Arm a = _arms[side];
+		if (a.Held != null && IsInstanceValid(a.Held) && a.Held != _arms[1 - side].Held)
+		{
+			a.Upper.RemoveCollisionExceptionWith(a.Held);
+			a.Fore.RemoveCollisionExceptionWith(a.Held);
+		}
+		a.Held = prop;
+		if (prop != null)
+		{
+			a.Upper.AddCollisionExceptionWith(prop);
+			a.Fore.AddCollisionExceptionWith(prop);
+		}
+	}
 }
diff --git a/scripts/PlayerRig.cs b/scripts/PlayerRig.cs
index c4241c4..e26b0c6 100644
--- a/scripts/PlayerRig.cs
+++ b/scripts/PlayerRig.cs
@@ -4,7 +4,8 @@ using Godot;
 // Boneworks-style stick locomotion and the play-space reconciliation. Runs everything in one
 // physics tick, in this order:
 //   1. discrete origin jumps made by other code (spawn, teleport markers) carry the body along;
-//   2. stick: left = move (head-relative), right X = turn (snap by default, SmoothTurn for smooth);
+//   2. stick: left = move (head-relative), right X = turn (snap by default, SmoothTurn for smooth),
+//      right Y = crouch (down lowers, up raises — RagdollDriver.StickCrouch); right A = jump;
 //   3. the ragdoll's OriginCorrection (push-back at walls, floor follows the ground, falls);
 //   4. True Body solve from the corrected camera/controllers, then the ragdoll's muscles.
 // Waits for the calibrated BodyProfile like everything else; rebuilds on recalibration.
@@ -18,6 +19,8 @@ public partial class PlayerRig : Node
     public const float SmoothTurnSpeed = 2.5f;     // rad/s
     public const float SnapTurnThreshold = 0.7f;
     public const float SnapTurnRearm = 0.4f;
+    public const float StickCrouchSpeed = 1.2f;    // m/s at full stick
+    public const float StickCrouchHeadroom = 0.5f; // the stick can lower the eyes to this height (a crawl)
     public const float JumpDistance = 0.5f;        // an origin move this big in one tick = teleport, not motion
     public const float JumpAngle = 0.1f;           // rad
     private const float GhostLagDistance = 0.1f;
@@ -33,9 +36,17 @@ public partial class PlayerRig : Node
     private bool _haveLastOrigin;
     private Vector3 _moveVelocity;
     private bool _snapArmed = true;
+    private bool _jumpPrev;
     private readonly MeshInstance3D[] _ghosts = new MeshInstance3D[2];
     private bool _rebuild = true;
     private RagdollDriver _driver;
+    // Render interpolation of the play space (smooth-camera bible, VR edition): physics moves the
+    // origin every tick, but the body is DRAWN interpolated between the last two ticks. A camera
+    // stepping with the raw origin while the body glides a tick behind looks like the body is in
+    // two places at once when you move and look at it. So physics owns _physOrigin and every
+    // frame the visible origin is the same interpolation of it the bodies get.
+    private Transform3D _physOrigin, _prevPhysOrigin, _shownOrigin;
+    private bool _interpolateOrigin;
 
     public PlayerRagdoll Ragdoll => _ragdoll;
     public static bool Spectator { get; private set; }
@@ -70,6 +81,8 @@ public partial class PlayerRig : Node
     public override void _Ready()
     {
         _instance = this;
+        ProcessPriority = -100;          // place the interpolated origin before anything reads it this frame
+        ProcessPhysicsPriority = -100;   // restore the physics origin before anything uses it this tick
         _origin = GetNode<XROrigin3D>("../XROrigin3D");
         _camera = GetNode<XRCamera3D>("../XROrigin3D/XRCamera3D");
         _left = GetNode<XRController3D>("../XROrigin3D/LeftHand");
@@ -114,8 +127,10 @@ public partial class PlayerRig : Node
         if (profile == null || Spectator)
         {
             _haveLastOrigin = false;
+            _interpolateOrigin = false;
             return;
         }
+        RestorePhysicsOrigin();
 
         // 1. Someone else moved the play space discretely: bring the body along.
         Transform3D origin = _origin.GlobalTransform;
@@ -134,10 +149,34 @@ public partial class PlayerRig : Node
         _origin.GlobalTransform = o;
         _lastOrigin = _origin.GlobalTransform;
         _haveLastOrigin = true;
+        _prevPhysOrigin = _interpolateOrigin && !IsJump(_physOrigin, _lastOrigin) ? _physOrigin : _lastOrigin;
+        _physOrigin = _shownOrigin = _lastOrigin;
+        _interpolateOrigin = true;
+    }
+
+    // The origin on screen is interpolated; physics must run on the real one. Anyone else who moved
+    // the origin since (teleport marker, menu) is respected as the new real one.
+    private void RestorePhysicsOrigin()
+    {
+        if (!_interpolateOrigin)
+            return;
+        Transform3D current = _origin.GlobalTransform;
+        if (current.IsEqualApprox(_shownOrigin))
+            _origin.GlobalTransform = _physOrigin;
+        else
+            _physOrigin = _prevPhysOrigin = current;
     }
 
     public override void _Process(double delta)
     {
+        if (_interpolateOrigin && !Spectator)
+        {
+            Transform3D current = _origin.GlobalTransform;
+            if (!current.IsEqualApprox(_shownOrigin))
+                _physOrigin = _prevPhysOrigin = current;  // moved by someone else: show it as is
+            _shownOrigin = _prevPhysOrigin.InterpolateWith(_physOrigin, (float)Engine.GetPhysicsInterpolationFraction());
+            _origin.GlobalTransform = _shownOrigin;
+        }
         for (int i = 0; i < 2; i++)
         {
             XRController3D c = i == 0 ? _left : _right;
@@ -178,9 +217,9 @@ public partial class PlayerRig : Node
         Vector3 desired = Vector3.Zero;
         if (move.Length() > StickDeadzone)
         {
-            Vector3 fwd = -_camera.GlobalTransform.Basis.Z;
-            fwd.Y = 0f;
-            fwd = fwd.LengthSquared() > 1e-6f ? fwd.Normalized() : Vector3.Forward;
+            Vector3 fwd = BodyMath.HeadFacing(_camera.GlobalTransform.Basis.Orthonormalized());
+            if (fwd == Vector3.Zero)
+                fwd = -Solver.YawBasis.Z;
             Vector3 rightDir = fwd.Cross(Vector3.Up);
             float mag = Mathf.Clamp((move.Length() - StickDeadzone) / (1f - StickDeadzone), 0f, 1f);
             desired = (fwd * move.Y + rightDir * move.X).Normalized() * (mag * MoveSpeed);
@@ -192,6 +231,23 @@ public partial class PlayerRig : Node
         if (_moveVelocity != Vector3.Zero)
             _origin.GlobalPosition += _moveVelocity * dt;
 
+        // Jump: right A, on the press.
+        bool jump = _right.IsButtonPressed("ax_button");
+        if (jump && !_jumpPrev)
+            _ragdoll.Jump();
+        _jumpPrev = jump;
+
+        // Crouch: right stick held down lowers the body, up raises it back (the stick's dominant
+        // axis decides between crouch and turn).
+        bool vertical = Mathf.Abs(turn.Y) > Mathf.Abs(turn.X);
+        if (vertical && Mathf.Abs(turn.Y) > StickDeadzone)
+        {
+            float max = Mathf.Max(0f, BodyProfile.Current.EyeHeight - StickCrouchHeadroom);
+            _driver.StickCrouch = Mathf.Clamp(_driver.StickCrouch - turn.Y * StickCrouchSpeed * dt, 0f, max);
+        }
+        if (vertical)
+            turn.X = 0f;
+
         // Turn about the head.
         float angle = 0f;
         if (SmoothTurn)
diff --git a/scripts/RagdollDriver.cs b/scripts/RagdollDriver.cs
index 8763a8b..f80eb6c 100644
--- a/scripts/RagdollDriver.cs
+++ b/scripts/RagdollDriver.cs
@@ -68,6 +68,11 @@ public sealed class RagdollDriver
     public TrueBodySolver Solver;
     public PlayerRagdoll Ragdoll;
     public bool RebuildRequested = true;
+    // Stick crouch (right stick down), metres: the play-space floor is treated as this far ABOVE where
+    // it is. The True Body then reads the head as that much lower (crouch pose), ground control and
+    // the view's re-centering settle the play space that far below the ground — so the camera rides
+    // down with the crouching body, and nothing feeds back (same play-space-relative rule as 2.5).
+    public float StickCrouch;
     private double _now;
 
     // origin = play space (modified by the correction); raw* = origin-local tracked poses as last
@@ -79,15 +84,16 @@ public sealed class RagdollDriver
         _now += dt;
         Transform3D head = Head.Sample(rawHead, _now), left = Left.Sample(rawLeft, _now), right = Right.Sample(rawRight, _now);
         if (Ragdoll.Built && !RebuildRequested)
-            origin.Origin += Ragdoll.OriginCorrection((origin * head).Origin, origin.Origin.Y, dt);
+            origin.Origin += Ragdoll.OriginCorrection((origin * head).Origin, origin.Origin.Y + StickCrouch, dt);
+        float floorY = origin.Origin.Y + StickCrouch;
         Transform3D h = origin * head, l = origin * left, r = origin * right;
-        Solver.Solve(profile, h, l, r, origin.Origin.Y, dt);
+        Solver.Solve(profile, h, l, r, floorY, dt);
         if (RebuildRequested || !Ragdoll.Built)
         {
             Ragdoll.Build(profile, Solver, l, r);
             RebuildRequested = false;
         }
         Vector3 lv = origin.Basis * Left.Velocity + moveVelocity, rv = origin.Basis * Right.Velocity + moveVelocity;
-        Ragdoll.Step(Solver, l, r, lv, rv, origin.Origin.Y, dt);
+        Ragdoll.Step(Solver, l, r, lv, rv, floorY, dt);
     }
 }
diff --git a/scripts/RagdollSpike.cs b/scripts/RagdollSpike.cs
index c9bad63..7ec3a7b 100644
--- a/scripts/RagdollSpike.cs
+++ b/scripts/RagdollSpike.cs
@@ -38,6 +38,7 @@ public partial class RagdollSpike : Node3D
     private Transform3D Right => _origin * Tracked(2, _rightLocal);
 
     private bool _realInput = true, _noiseOn = true, _holdOn = true;
+    private string[] _only;   // `-- only=jump,fall`: run just the phases whose names contain one of these
     private const float TrackingHz = 90f;
     private readonly Transform3D[] _held = new Transform3D[3];
     private readonly long[] _heldFrame = { -1, -1, -1 };
@@ -71,6 +72,8 @@ public partial class RagdollSpike : Node3D
                 _noiseOn = false;
             if (arg == "nohold")
                 _holdOn = false;
+            if (arg.StartsWith("only="))
+                _only = arg[5..].Split(',');
         }
         GD.Print($"RAGDOLL: input mode {(_realInput ? "REAL (90 Hz tracking, jitter)" : "ideal")} at {Engine.PhysicsTicksPerSecond} Hz physics");
         StaticBody3D floor = MakeStatic(new Vector3(40f, 1f, 40f), new Vector3(0f, -0.5f, 0f), 29);
@@ -106,11 +109,18 @@ public partial class RagdollSpike : Node3D
         _phases.Add(("holds poses (stand, crouch, deep crouch, lean, reach, kneel) without view/body drift", Rest, TickPoseHold, 18f, FinishPoseHold));
         _phases.Add(("hanging from a bar keeps the view on the body", () => SetupBarHang(), TickHang, 4f, FinishHang));
         _phases.Add(("climbs a wall hand over hand (grab, pull, regrab higher)", SetupClimbWall, TickClimbWall, 8f, FinishClimbWall));
-        _phases.Add(("walks off a 1 m ledge and lands without sinking away from the view", SetupLedgeTop, TickDrop, 4f, FinishDrop));
+        _phases.Add(("walks off a 1 m ledge and lands: a dip the view follows, no bounce", () => SetupLedgeTop(1f), TickDrop, 4f, () => FinishDrop(1f)));
+        _phases.Add(("big fall (5 m): legs fold fully, then it recovers", () => SetupLedgeTop(5f), TickDrop, 5f, () => FinishDrop(5f)));
+        _phases.Add(("standing jump", Rest, t => TickJump(0f), 4f, () => FinishJump(crouched: false)));
+        _phases.Add(("jump from a crouch goes higher", Rest, t => TickJump(0.45f), 4.5f, () => FinishJump(crouched: true)));
+        _phases.Add(("looks down past vertical while crouched (body doesn't flip around)", Rest, TickLookDown, 5f, FinishLookDown));
+        _phases.Add(("stick crouch lowers the body and the view, and stands back up", Rest, TickStickCrouch, 6f, FinishStickCrouch));
         _phases.Add(("standing on a seesaw tips it (body weight reaches movable ground)", SetupSeesaw, _ => { }, 3f, FinishSeesaw));
         _phases.Add(("playground: swing board hangs, seesaw on its pivot, big plank grabbable", SetupPlayground, _ => { }, 2f, FinishPlayground));
         _phases.Add(("walks up an 18° ramp", () => SetupRamp(18f), _ => _stickVelocity = new Vector3(0f, 0f, -1.2f), 4f, () => FinishRamp(true)));
         _phases.Add(("can't walk up a 40° ramp", () => SetupRamp(40f), _ => _stickVelocity = new Vector3(0f, 0f, -1.2f), 4f, () => FinishRamp(false)));
+        if (_only != null)
+            _phases.RemoveAll(ph => ph.Name != "hinge sign" && !Array.Exists(_only, o => ph.Name.Contains(o)));
         Next();
     }
 
@@ -153,6 +163,8 @@ public partial class RagdollSpike : Node3D
         _finite = true;
         _measureFrom = 1f;
         _stickVelocity = Vector3.Zero;
+        if (_driver != null)
+            _driver.StickCrouch = 0f;
         _phases[_phase].Setup();
         _snapsAtStart = _ragdoll.Snaps;
     }
@@ -662,38 +674,176 @@ public partial class RagdollSpike : Node3D
     }
 
 
-    // Start standing on a 1 m platform whose edge is 0.5 m ahead.
-    private void SetupLedgeTop()
+    // Start standing on a platform whose edge is 0.5 m ahead.
+    private void SetupLedgeTop(float height)
     {
         Rest();
-        _origin = new Transform3D(Basis.Identity, new Vector3(0f, 1f, 0f));
-        _stage.AddChild(MakeStatic(new Vector3(3f, 1f, 3f), new Vector3(0f, 0.5f, 1f), 29));
+        _origin = new Transform3D(Basis.Identity, new Vector3(0f, height, 0f));
+        _stage.AddChild(MakeStatic(new Vector3(3f, height, 3f), new Vector3(0f, height * 0.5f, 1f), 29));
+        _dropEyeErr = _dropEyeErrLate = _dropRebound = 0f;
+        _dropMinPelvis = float.MaxValue;
+        _dropStand = 0f;
     }
 
-    private float _dropEyeErr, _dropMinPelvis = float.MaxValue;
+    private float _dropEyeErr, _dropEyeErrLate, _dropMinPelvis = float.MaxValue, _dropStand, _dropRebound;
 
     private void TickDrop(float dt)
     {
         _stickVelocity = _t > 0.5f && _t < 2f ? new Vector3(0f, 0f, -1.2f) : Vector3.Zero;
-        if (_ragdoll.Built && !_needBuild && _t > 0.5f)
+        if (!_ragdoll.Built || _needBuild)
+            return;
+        float pelvis = _ragdoll.Pelvis.GlobalPosition.Y;
+        if (_t < 0.5f)
+            _dropStand = pelvis - _ragdoll.GroundY;   // standing hips above the feet
+        else
         {
             _dropEyeErr = Mathf.Max(_dropEyeErr, _ragdoll.Eye.DistanceTo(Camera.Origin));
             if (_ragdoll.Grounded && _ragdoll.GroundY < 0.5f)
-                _dropMinPelvis = Mathf.Min(_dropMinPelvis, _ragdoll.Pelvis.GlobalPosition.Y);
+            {
+                if (pelvis < _dropMinPelvis)
+                {
+                    _dropMinPelvis = pelvis;
+                    _dropRebound = pelvis;
+                }
+                _dropRebound = Mathf.Max(_dropRebound, pelvis);
+            }
+            if (_dropMinPelvis < float.MaxValue && _ragdoll.Pelvis.LinearVelocity.Y > -0.5f)
+                _dropEyeErrLate = Mathf.Max(_dropEyeErrLate, _ragdoll.Eye.DistanceTo(Camera.Origin));
         }
     }
 
-    private bool FinishDrop()
+    private bool FinishDrop(float height)
     {
-        GD.Print($"RAGDOLL:   landing: eye vs camera max {_dropEyeErr:F3} m (limit 0.15), lowest pelvis after touchdown {_dropMinPelvis:F3} m (standing 0.99, limit > 0.7)");
-        bool landed = _dropEyeErr < 0.15f && _dropMinPelvis > 0.7f;
-        _dropEyeErr = 0f;
-        _dropMinPelvis = float.MaxValue;
+        float dip = _dropStand - _dropMinPelvis, overshoot = _dropRebound - _dropStand;
+        // The dip grows with the impact; a big fall folds the legs (hips near the ground). Rebound
+        // past the stance would be a bounce. The view rides the body throughout.
+        bool dipOk = height < 2f ? dip > 0.12f && dip < 0.5f : dip > 0.45f;
+        GD.Print($"RAGDOLL:   landing from {height} m: dip {dip:F3} m (stance {_dropStand:F3}), rebound above the stance {overshoot:F3} (limit 0.05), eye vs camera max {_dropEyeErr:F3} / after the impact {_dropEyeErrLate:F3} (limit 0.1)");
+        bool landed = dipOk && overshoot < 0.05f && _dropEyeErrLate < 0.1f;
         if (!landed)
             return false;
         GD.Print($"RAGDOLL:   drop: feet y {_ragdoll.GroundY:F3}, origin y {_origin.Origin.Y:F3}, pelvis {_ragdoll.Pelvis.GlobalPosition}, eye error {_ragdoll.Eye.DistanceTo(Camera.Origin):F3}, snaps {NewSnaps}");
         return _finite && NewSnaps == 0 && Mathf.Abs(_ragdoll.GroundY) < 0.05f && Mathf.Abs(_origin.Origin.Y) < 0.1f
-            && _ragdoll.Eye.DistanceTo(Camera.Origin) < 0.1f && _ragdoll.Pelvis.GlobalPosition.Z > -3f;
+            && _ragdoll.Eye.DistanceTo(Camera.Origin) < 0.1f && _ragdoll.Pelvis.GlobalPosition.Z > -3f
+            && Mathf.Abs(_ragdoll.Pelvis.GlobalPosition.Y - _ragdoll.GroundY - _dropStand) < 0.05f;
+    }
+
+    // ---------------------------------------------------------------- jump
+
+    private float _jumpStand, _jumpApex, _jumpEyeErr, _standJumpApex;
+    private bool _jumpPressed;
+
+    // Optionally squat (eyes `crouch` lower) first, then press jump at 2 s; the player keeps the pose.
+    private void TickJump(float crouch)
+    {
+        float k = Mathf.SmoothStep(0f, 1f, Mathf.Clamp((_t - 0.8f) / 0.8f, 0f, 1f)) * (crouch > 0f ? 1f : 0f);
+        _headLocal = new Transform3D(new Basis(Vector3.Right, -0.2f * k), new Vector3(0f, EyeHeight - crouch * k, -0.05f * k));
+        _leftLocal = new Transform3D(Basis.Identity, new Vector3(-0.2f, 1.0f - crouch * k, -0.3f));
+        _rightLocal = new Transform3D(Basis.Identity, new Vector3(0.2f, 1.0f - crouch * k, -0.3f));
+        _measureFrom = float.MaxValue;
+        if (!_ragdoll.Built || _needBuild)
+            return;
+        float pelvis = _ragdoll.Pelvis.GlobalPosition.Y;
+        if (_t < 0.7f)
+        {
+            _jumpStand = pelvis;
+            _jumpApex = 0f;
+            _jumpEyeErr = 0f;
+            _jumpPressed = false;
+        }
+        if (_t >= 2f && !_jumpPressed)
+        {
+            _jumpPressed = true;
+            _ragdoll.Jump();
+        }
+        if (_jumpPressed)
+        {
+            _jumpApex = Mathf.Max(_jumpApex, pelvis - _jumpStand);
+            _jumpEyeErr = Mathf.Max(_jumpEyeErr, _ragdoll.Eye.DistanceTo(Camera.Origin));
+        }
+    }
+
+    private bool FinishJump(bool crouched)
+    {
+        GD.Print($"RAGDOLL:   {(crouched ? "crouched" : "standing")} jump: hips rose {_jumpApex:F3} m above the standing stance, eye vs camera max {_jumpEyeErr:F3}, grounded {_ragdoll.Grounded}, jumping {_ragdoll.Jumping}, snaps {NewSnaps}");
+        bool ok = _finite && NewSnaps == 0 && _ragdoll.Grounded && !_ragdoll.Jumping && _jumpEyeErr < 0.12f && _origin.Origin.Length() < 0.15f;
+        if (!crouched)
+        {
+            _standJumpApex = _jumpApex;
+            return ok && _jumpApex > 0.3f && _jumpApex < 0.65f;
+        }
+        return ok && _jumpApex > _standJumpApex + 0.1f;
+    }
+
+    // ---------------------------------------------------------------- looking down past vertical
+
+    private float _lookYaw0, _lookYawMax, _lookChestMax, _lookPitchMax;
+
+    private static float YawOfBody(RigidBody3D b)
+    {
+        Vector3 f = BodyMath.HeadFacing(b.GlobalTransform.Basis.Orthonormalized());
+        return f == Vector3.Zero ? 0f : BodyMath.YawOf(f);
+    }
+
+    // Crouch (eyes 1.0 m), then look down to 125° below the horizon (chin on the chest, looking
+    // behind the feet) and back, hands down near the floor — interacting with stuff on the ground.
+    private void TickLookDown(float dt)
+    {
+        float k = Mathf.SmoothStep(0f, 1f, Mathf.Min(_t / 1f, 1f));
+        float pitch = Mathf.DegToRad(125f) * Mathf.Sin(Mathf.Pi * Mathf.Clamp((_t - 1.5f) / 3f, 0f, 1f));
+        _lookPitchMax = Mathf.Max(_lookPitchMax, pitch);
+        Basis head = new(Vector3.Right, -pitch);
+        Vector3 pivot = new(0f, Mathf.Lerp(EyeHeight, 1.0f, k) + TrueBodySolver.EyeToNeckPivot.Y, -0.1f * k + TrueBodySolver.EyeToNeckPivot.Z);
+        _headLocal = new Transform3D(head, pivot - head * TrueBodySolver.EyeToNeckPivot);
+        _leftLocal = new Transform3D(Aim(Vector3.Down + Vector3.Forward), new Vector3(-0.2f, Mathf.Lerp(1.0f, 0.3f, k), -0.4f));
+        _rightLocal = new Transform3D(Aim(Vector3.Down + Vector3.Forward), new Vector3(0.2f, Mathf.Lerp(1.0f, 0.3f, k), -0.4f));
+        _measureFrom = float.MaxValue;
+        if (!_ragdoll.Built || _needBuild)
+            return;
+        if (_t < 1.4f)
+        {
+            _lookYaw0 = YawOfBody(_ragdoll.Pelvis);
+            _lookYawMax = _lookChestMax = _lookPitchMax = 0f;
+            return;
+        }
+        _lookYawMax = Mathf.Max(_lookYawMax, Mathf.Abs(Mathf.AngleDifference(_lookYaw0, YawOfBody(_ragdoll.Pelvis))));
+        _lookChestMax = Mathf.Max(_lookChestMax, Mathf.Abs(Mathf.AngleDifference(_lookYaw0, YawOfBody(_ragdoll.Chest))));
+    }
+
+    private bool FinishLookDown()
+    {
+        GD.Print($"RAGDOLL:   look down to {Mathf.RadToDeg(_lookPitchMax):F0}°: pelvis yaw change max {Mathf.RadToDeg(_lookYawMax):F1}°, chest {Mathf.RadToDeg(_lookChestMax):F1}° (limit 15), eye error {_ragdoll.Eye.DistanceTo(Camera.Origin):F3}, snaps {NewSnaps}");
+        return _finite && NewSnaps == 0 && _lookYawMax < Mathf.DegToRad(15f) && _lookChestMax < Mathf.DegToRad(15f)
+            && _ragdoll.Eye.DistanceTo(Camera.Origin) < 0.08f;
+    }
+
+    // ---------------------------------------------------------------- stick crouch
+
+    private float _stickEyeLow, _stickOriginLow, _stickEyeErr;
+
+    private void TickStickCrouch(float dt)
+    {
+        _measureFrom = float.MaxValue;
+        if (_driver == null)
+            return;
+        // Hold the stick down for 1 s (1.2 m/s → capped at 0.6 m here), hold, then back up.
+        float c = _t < 0.5f ? 0f : _t < 3.5f ? Mathf.Min(0.6f, (_t - 0.5f) * 1.2f) : Mathf.Max(0f, 0.6f - (_t - 3.5f) * 1.2f);
+        _driver.StickCrouch = c;
+        if (_t > 2.5f && _t < 3.4f && _ragdoll.Built)
+        {
+            _stickEyeLow = _ragdoll.Eye.Y;
+            _stickOriginLow = _origin.Origin.Y;
+            _stickEyeErr = Mathf.Max(_stickEyeErr, _ragdoll.Eye.DistanceTo(Camera.Origin));
+        }
+    }
+
+    private bool FinishStickCrouch()
+    {
+        GD.Print($"RAGDOLL:   stick crouch 0.6 m: eye y {_stickEyeLow:F3} (standing {EyeHeight}), origin y {_stickOriginLow:F3}, eye vs camera {_stickEyeErr:F3}; back up: eye y {_ragdoll.Eye.Y:F3}, origin y {_origin.Origin.Y:F3}, snaps {NewSnaps}");
+        bool ok = _finite && NewSnaps == 0 && Mathf.Abs(_stickEyeLow - (EyeHeight - 0.6f)) < 0.1f && Mathf.Abs(_stickOriginLow + 0.6f) < 0.08f
+            && _stickEyeErr < 0.06f && Mathf.Abs(_ragdoll.Eye.Y - EyeHeight) < 0.06f && Mathf.Abs(_origin.Origin.Y) < 0.06f;
+        _stickEyeErr = 0f;
+        return ok;
     }
 
     private Vector3 _crouchPelvis;
diff --git a/scripts/TrueBody.cs b/scripts/TrueBody.cs
index e5d8c94..3f8e03e 100644
--- a/scripts/TrueBody.cs
+++ b/scripts/TrueBody.cs
@@ -14,6 +14,7 @@ public sealed class TrueBodySolver
     public const float ChestLeanMax = 0.75f;              // rad (~43°) at a deep crouch
     public const float CrouchRange = 0.5f;                // crouch factor 1 when eyes are this fraction of standing eye height lower
     public const float HeadPitchToChest = 0.25f;
+    public const float MaxHeadPitch = 2.4f;               // rad; chin-to-chest looking at your feet goes past 90°
     // Crawl: when the head gets so low that the hips would go through the floor, the trunk tips
     // further (pivoting at the hips, hips kicking back) up to nearly horizontal (Nimso: lower = crawl).
     public const float CrawlLeanMax = 1.45f;              // rad (~83°)
@@ -79,16 +80,19 @@ public sealed class TrueBodySolver
         WristTarget[1] = right * new Vector3(0f, 0f, WristOffset);
 
         // Torso yaw: HMD yaw blended toward the hands when they're out in front (decoupled from the head).
+        // Facing from BodyMath.HeadFacing: looking down past vertical must not turn the body around.
         Vector3 headFwd = -headBasis.Z;
-        float hmdYaw = Mathf.Atan2(-headFwd.X, -headFwd.Z);
+        Vector3 flatFwd = BodyMath.HeadFacing(headBasis);
+        if (flatFwd == Vector3.Zero)
+            flatFwd = new Basis(Vector3.Up, _yaw) * Vector3.Forward;
+        float hmdYaw = BodyMath.YawOf(flatFwd);
         float targetYaw = hmdYaw;
         Vector3 toHands = (WristTarget[0] + WristTarget[1]) * 0.5f - Eye;
         toHands.Y = 0f;
-        Vector3 flatFwd = new Vector3(headFwd.X, 0f, headFwd.Z);
-        if (toHands.LengthSquared() > 1e-4f && flatFwd.LengthSquared() > 1e-6f)
+        if (toHands.LengthSquared() > 1e-4f)
         {
-            float handsYaw = Mathf.Atan2(-toHands.X, -toHands.Z);
-            float forwardness = Mathf.Clamp(toHands.Dot(flatFwd.Normalized()) / YawForwardness, 0f, 1f);
+            float handsYaw = BodyMath.YawOf(toHands);
+            float forwardness = Mathf.Clamp(toHands.Dot(flatFwd) / YawForwardness, 0f, 1f);
             targetYaw = Mathf.LerpAngle(hmdYaw, handsYaw, forwardness * YawHandsWeight);
         }
         if (!Initialized)
@@ -102,7 +106,8 @@ public sealed class TrueBodySolver
         float pivotAboveFloor = NeckPivot.Y - floorY;
         float standingPivot = p.EyeHeight + EyeToNeckPivot.Y;
         Crouch = Mathf.Clamp((standingPivot - pivotAboveFloor) / (CrouchRange * p.EyeHeight), 0f, 1f);
-        float headPitchDown = Mathf.Max(0f, -Mathf.Asin(Mathf.Clamp(headFwd.Y, -1f, 1f)));
+        // Pitch against the facing, so it keeps growing past vertical (asin peaks at 90°).
+        float headPitchDown = Mathf.Clamp(Mathf.Atan2(-headFwd.Y, headFwd.Dot(flatFwd)), 0f, MaxHeadPitch);
         float lean = Crouch * ChestLeanMax + headPitchDown * HeadPitchToChest;
         float trunk = TrunkRatio * p.Stature;
         float neckLen = Mathf.Max(0.05f, p.ShoulderDrop + EyeToNeckPivot.Y - NeckBaseAboveShoulders);
diff --git a/scripts/WorldPanel.cs b/scripts/WorldPanel.cs
index a25dd2e..84a937d 100644
--- a/scripts/WorldPanel.cs
+++ b/scripts/WorldPanel.cs
@@ -1,7 +1,7 @@
 using Godot;
 
 // The in-VR menu: a MenuScreen (Godot Control UI in a SubViewport on a thin 0.36x0.24 m
-// panel) showing MainMenu. This node is the XR glue: summon/dismiss with ax_button (A/X),
+// panel) showing MainMenu. This node is the XR glue: summon/dismiss with the LEFT ax_button (X; right A is jump),
 // grip-drag (direct or along the laser), re-orient toward the head, feed both controllers'
 // pointer rays into the screen, click sound + haptics. PARENTED UNDER XROrigin3D (fixed in the
 // player's room; game locomotion carries it).
@@ -114,8 +114,7 @@ public partial class WorldPanel : Node3D
 
     public override void _Process(double delta)
     {
-        PollSummon(_left, 0);
-        PollSummon(_right, 1);
+        PollSummon(_left, 0);   // left X only: right A is jump
         if (Visible)
         {
             UpdateDrag(_left, 0);