VR-Mess/research/sources/nimso-transcripts/vOBowFNR3HI.txt

# WHY PHYSICS WHY NOT? - Moving in Unity - Physics in Unity - Intermediate Tutorial Series Part 4 (vOBowFNR3HI, 518s)

it's me names Sony welcome to part 4 of my unity tutorial series moving in unity today we're going to be discussing the basics of physics in unity now this is actually a precursor to power 5 where I'm going to be using a physics system to move our object around and we can see here from a previous part that we have movement based on our camera the problem with this movement is that it can go through walls let's highlight that by making a wall so you can move here I've duplicated this cube down here which I'm now going to scale up and we're going to scale it back as well just to make it a wall so here we can see we've got a wall in fact I placed it on the side of our camera oh well camera moves so that's ok so you can see here that because we're moving our object just by its transform and we have no physics on it whatsoever you can just move it right through the wall that's problem of course but we can fix that let's have a look first at what our player actually is it's just a cube with a transform and a script I'm going to move that back now and what I'm going to place in the scene instead is a sphere this sphere I'm going to put it at 0 0 on the x and y are z values but I'm going to leave it at 2 on the Y and I'm going to move it a little bit to the left duplicate it using control D and then move it to the right we're going to give it material here we are and let's make a second material as well again ctrl T ctrl D sorry we can duplicate materials we can duplicate anything in unity using ctrl D by selecting it and then change the material color I'm going to go with a nice blue and we're going to attach that to the one on our right okay let's press play we can see both of our spheres here and they don't move of course we haven't attached a script to them now this one on the left you can see here that we have a sphere Collider of course we have the same on the right but we're going to remove this Collider from the one on the right there's a reason and this video is all about determining which physics system were actually going to use in our game and I'll explain to you why I'm not going to be using a rigidbody first you have to explain to you what the rigidbody actually does so down here in add component I'm going to add a rigidbody to our red sphere and on our right on us the blue sphere I'm going to add a character controller now character controller is a special type of physics object which allows unity to literally move an object with some collision but it's entirely script based it's entirely unity zone construct whereas the rigidbody itself uses the pure physics system of the Nvidia physics physics engine okay which is the physics engine directly from unity from Nvidia so let's press play and see what happens to our X fear automatically you can see that it falls and hits the bottom floor that's because it is quite literally a physics object because it's got gravity as well we can switch it off and on it's got mass and it has as well it gives you the opportunity to add constraints which would allow you to stop it from moving in those specific axes including rotations so you can stop its rotation from being affected by physics directly the one on the right didn't fall that's because character controller doesn't actually perform any physics at all it does calculations when you move it using unities own special movement functions to move it through objects and determine what's in front of it when you move it specifically when you move it and that's very important to understand it means when an object is flying towards this it'll bounce off the red one the red one will roll away but it'll bounce off the blue one the blue one won't even detect anything has happened what we can do with the red one to have complete physical code control scripted control over it is switch it to is kinematic now this gives us full control over the object and you can see here that it doesn't do any of its actual physics internally by itself let's see to moving those objects now here on our player grab our script and we're going to add two objects very quickly one is a rigidbody oops I wish I could spell correctly one is a rigidbody will call it sphere one and the other is a character controller which we'll call it sphere to correct controller there we go right so what we're going to do here in fact is duplicate our movement control and attach it to sphere one which is a rigidbody duplicate that and attach it to sphere to which in fact Nik requires us to access the transform directly because character controllers don't have their own position very very values switch back over make sure that they are attached to our new reference variables so sphere one and sphere two when we press play you'll see something happening we now have full movement on both of those objects the red one lags slightly we'll explain that later on but you can see even now even though they both have physics colliders on them they can still move directly through the wall now that's about the limitations that we have on the red sphere because it's a rigidbody object and it's designed to move using the actual physics engine but the one on the right the blue one it actually uses unities own clever system for moving objects and determining walls we're going to program that very simple now we use unity zone internal function it's a switch back over to your code change dot position so that it's dot move and now that's an actual function so we're not actually adding to it remove the add equals and change it into an open bracket and at the end close the bracket so you can see here by the highlighted red section that are within our move move function we're applying that movement that we looked at in the previous movement accord as well save it and switch over to the game and press play you'll see that it's exactly the same movement however there's one different the difference is that the blue one will now trace every movement every frame and determine whether there's a wall in front of it Tara he gets stuck on the wall because it can't go beyond that point again this will also work on any diagonals so you can see here we're going diagonally and we can go sideways into the wall and it slides along the edges as well it's very very useful because it does all of our movement control completely scripted but it also prevents it from moving through walls that's why we're going to use a character controller for our movement not a physics object in this case it's because we want to understand how the physics calculations are done rather than just using what is already built for us this is what we're using because we're going to control our object from script entirely we're going to program our gravity we're going to program our velocity and acceleration we're going to program in our jumps we don't want to use the physics engine for everything because that is designed primarily for realistic physics and realistic collisions bouncing friction air drag all of that kind of stuff that's the end of this video in the next video we're going to remove our red sphere and start working with actually moving our object and applying gravity moving it with a lot of physics calculations we're going to clean up our cord as well so be sure to check out the next video this one I understand was a bit boring and it was one of those videos that needed to be done because we needed to understand why we chose one object over the other thanks for watching know bye [Music]
	`# WHY PHYSICS WHY NOT? - Moving in Unity - Physics in Unity - Intermediate Tutorial Series Part 4 (vOBowFNR3HI, 518s)`

	it's me names Sony welcome to part 4 of my unity tutorial series moving in unity today we're going to be discussing the basics of physics in unity now this is actually a precursor to power 5 where I'm going to be using a physics system to move our object around and we can see here from a previous part that we have movement based on our camera the problem with this movement is that it can go through walls let's highlight that by making a wall so you can move here I've duplicated this cube down here which I'm now going to scale up and we're going to scale it back as well just to make it a wall so here we can see we've got a wall in fact I placed it on the side of our camera oh well camera moves so that's ok so you can see here that because we're moving our object just by its transform and we have no physics on it whatsoever you can just move it right through the wall that's problem of course but we can fix that let's have a look first at what our player actually is it's just a cube with a transform and a script I'm going to move that back now and what I'm going to place in the scene instead is a sphere this sphere I'm going to put it at 0 0 on the x and y are z values but I'm going to leave it at 2 on the Y and I'm going to move it a little bit to the left duplicate it using control D and then move it to the right we're going to give it material here we are and let's make a second material as well again ctrl T ctrl D sorry we can duplicate materials we can duplicate anything in unity using ctrl D by selecting it and then change the material color I'm going to go with a nice blue and we're going to attach that to the one on our right okay let's press play we can see both of our spheres here and they don't move of course we haven't attached a script to them now this one on the left you can see here that we have a sphere Collider of course we have the same on the right but we're going to remove this Collider from the one on the right there's a reason and this video is all about determining which physics system were actually going to use in our game and I'll explain to you why I'm not going to be using a rigidbody first you have to explain to you what the rigidbody actually does so down here in add component I'm going to add a rigidbody to our red sphere and on our right on us the blue sphere I'm going to add a character controller now character controller is a special type of physics object which allows unity to literally move an object with some collision but it's entirely script based it's entirely unity zone construct whereas the rigidbody itself uses the pure physics system of the Nvidia physics physics engine okay which is the physics engine directly from unity from Nvidia so let's press play and see what happens to our X fear automatically you can see that it falls and hits the bottom floor that's because it is quite literally a physics object because it's got gravity as well we can switch it off and on it's got mass and it has as well it gives you the opportunity to add constraints which would allow you to stop it from moving in those specific axes including rotations so you can stop its rotation from being affected by physics directly the one on the right didn't fall that's because character controller doesn't actually perform any physics at all it does calculations when you move it using unities own special movement functions to move it through objects and determine what's in front of it when you move it specifically when you move it and that's very important to understand it means when an object is flying towards this it'll bounce off the red one the red one will roll away but it'll bounce off the blue one the blue one won't even detect anything has happened what we can do with the red one to have complete physical code control scripted control over it is switch it to is kinematic now this gives us full control over the object and you can see here that it doesn't do any of its actual physics internally by itself let's see to moving those objects now here on our player grab our script and we're going to add two objects very quickly one is a rigidbody oops I wish I could spell correctly one is a rigidbody will call it sphere one and the other is a character controller which we'll call it sphere to correct controller there we go right so what we're going to do here in fact is duplicate our movement control and attach it to sphere one which is a rigidbody duplicate that and attach it to sphere to which in fact Nik requires us to access the transform directly because character controllers don't have their own position very very values switch back over make sure that they are attached to our new reference variables so sphere one and sphere two when we press play you'll see something happening we now have full movement on both of those objects the red one lags slightly we'll explain that later on but you can see even now even though they both have physics colliders on them they can still move directly through the wall now that's about the limitations that we have on the red sphere because it's a rigidbody object and it's designed to move using the actual physics engine but the one on the right the blue one it actually uses unities own clever system for moving objects and determining walls we're going to program that very simple now we use unity zone internal function it's a switch back over to your code change dot position so that it's dot move and now that's an actual function so we're not actually adding to it remove the add equals and change it into an open bracket and at the end close the bracket so you can see here by the highlighted red section that are within our move move function we're applying that movement that we looked at in the previous movement accord as well save it and switch over to the game and press play you'll see that it's exactly the same movement however there's one different the difference is that the blue one will now trace every movement every frame and determine whether there's a wall in front of it Tara he gets stuck on the wall because it can't go beyond that point again this will also work on any diagonals so you can see here we're going diagonally and we can go sideways into the wall and it slides along the edges as well it's very very useful because it does all of our movement control completely scripted but it also prevents it from moving through walls that's why we're going to use a character controller for our movement not a physics object in this case it's because we want to understand how the physics calculations are done rather than just using what is already built for us this is what we're using because we're going to control our object from script entirely we're going to program our gravity we're going to program our velocity and acceleration we're going to program in our jumps we don't want to use the physics engine for everything because that is designed primarily for realistic physics and realistic collisions bouncing friction air drag all of that kind of stuff that's the end of this video in the next video we're going to remove our red sphere and start working with actually moving our object and applying gravity moving it with a lot of physics calculations we're going to clean up our cord as well so be sure to check out the next video this one I understand was a bit boring and it was one of those videos that needed to be done because we needed to understand why we chose one object over the other thanks for watching know bye [Music]