Research: exhaustive Nimso Project TX study (82 video transcripts) + Boneworks/BIMOS rig reference

- research/nimso-project-tx.md: chronological per-video notes 2017-2026, topic synthesis,
  VR Messs scope, proportions & calibration (Winter/Drillis-Contini/Dempster tables verified),
  open unknowns
- research/sources/nimso-transcripts/: yt-dlp auto-caption transcripts + dated index (re-pullable)
- research/vr-physics-rig-hexabody.md: BIMOS/HexaBody/Boneworks reference, Box3D native joint
  mapping (spherical/motor/prismatic/distance), superseded-as-target note
- AGENTS/HANDOFF research pointers

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

research/sources/nimso-transcripts/rqLEL3kE4hc.txt

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+# How It Works 2 A - Half Life : Alyx - Hands & Physics (rqLEL3kE4hc, 1577s)
+
+it's me name sony welcome back to vr today we are back in the uh in half-life alex and we're on the second episode of how it works uh in this video we won't be talking about movement anymore although there is certain things about it which is mantling uh that i could describe uh but what in what we're doing instead is talking about the hands systems uh the the way that the physics hands work and uh well the works the way that the hands work in general now i'm gonna start this uh start this a little dialogue going so that we can open that door very soon uh but the first thing i want to talk about is actually not the physics in itself but rather uh the hands there are actually three sets of hands in the game that might not make any sense but one of them is an inherent element to vr and the other two are necessary for the way this game handles its physics so what are these elements well the first one you can see uh directly in the menus this hand here what you're seeing is the tracking hand so these are actually perfectly following my real world hands and have no physics or anything like that they are never offset from my tracking that is the raw tracking that you're seeing in the menu and of course they somewhat match in game but in game we do have some physics hands that affect things as well that's not always the case however the things that are the main element are the tracking that we're talking about here so tracking always the same you have two of them and they're always there no matter what most of the time your teleport point comes from your tracking unless of course in some cases it actually goes towards the physics so you can see if i push my hand you can actually see the teleport line moving with my hand however if i if i if i pause the game you can see i'm actually pointing directly and my my other hand is actually sticking in to that hand so there we go you can push that and you can see that actually it's being pushed along right so that the teleport line is actually coming from the physics and which i will mention as the second one so the first set we've got is the pure tracking which you see here right the second set we've got is the physics hand now the physics hand actually collides with everything in the scene however the thing with the physics hand is it is always there and it's never actually connected to anything now that may not make sense but we'll get to that in a moment it's never physically connected to anything it is never stopped by anything other than the movement system and i'll explain that as well the third element is well the third set of hands is what you're seeing so the tracking you can see it here you can see it in the menu the the animated hands the actual visual hands you see them all the time of course because they move around and they connect to things and stuff like that and then the physics hand you can't really directly see it but in most cases the visual hand will try and follow it as well right so how does this all fit together well it depends on what you're doing so the game has a certain element to it which is that it tries to make your visuals look a little bit more natural in the game world as opposed to matching your tracking so the first thing it does is actually manipulate your hands uh depending on what you're doing so when your hands are neat near to something which you can see here it actually manipulates the animation but we're going to ignore the animation for now what it does as well is it actually moves the hand position what you're seeing though is not the physics hand being manipulated so here you can see i can push this hand but that's where it actually hits so you can see that the physics hand is actually offset here the animated hand the visual hand is separate to the physics and and you know what the easiest way to see that is with that teleport line like i said that teleport line is actually matching our physics right now so if i put my hand like this you can see how it offsets from that physics and the same thing applies in other situations as well like when you're moving towards an object like this so you can see i'll keep my hand straight like this and you can see it rotates towards that thing now there's a very slight blend so that it tries to match my tracking in reality what i'm doing is this but it's sort of mostly matching the actual point here before i grab it right and again you can see the physics is actually matching the tracking matching the teleport line there and you can see how the physics hand is separate completely separated from the visual hat so this is how we're handling uh the idea of what you're seeing and how it manipulates physics as well they are separated you don't directly attach your hands to the physics systems now me in my own work i actually have done that in my personal work my my visual hands are directly connected to the physics hands so whenever you see that the virtual hands the visual hands doing somethingLine truncated