‫We'll come back.
‫In this video, we will have a look at the rigid body.
‫And therefore, what I'll do first is save my scene.
‫So let's save the scene as and I'm going to call that main because what we haven't done yet is save
‫scenes and you should that should do that regularly.
‫So you should save your scene.
‫And now you can see that here it says Main now.
‫So whenever you make a change and you want to keep that, you always should press control, save.
‫Or you could go here to save scenes.
‫All right.
‫So now let's go ahead and choose our player, because he already has a rigid body.
‫And as I said, there are multiple different properties.
‫We only had to look at use gravity yet.
‫So now let's have a look at the mass, for example, and therefore I would like to make our world a
‫bit bigger.
‫So I'm going to scale the underground up to five, five and five.
‫Actually, the Y value can stay one.
‫It doesn't matter because it doesn't really have a height.
‫Our plane.
‫So now let's have a look at our game mode.
‫All right, that's good.
‫And now I would like to use my own layout, which allows me to see my game from the scene view and the
‫game view.
‫At the same time here 2D is activated, so now I can only see the game from a 2D angle.
‫So I'm going to change that.
‫I'm deactivating this to two D button and now I can see it here as well.
‫So that can be useful in some occasions.
‫All right.
‫So now that is my game and my ball.
‫And now let's move the ball.
‫Let's run the game.
‫And as you can see, the ball is moving.
‫So now I'm activating or opening my hierarchy view.
‫I'm going to go to player.
‫And what I can do here is, for example, change the mass.
‫So if I change the mass to 2000 now and I'm going to pause the game, I'm going to change the mass to
‫2000, I'm going to start the game again.
‫And now I can barely move my ball, or even not at all, because my force that I'm applying is way too
‫little, or actually just a little bit.
‫I can move the ball very, very slowly.
‫So I'm applying the force, and that has to do with the speed and the mass, of course.
‫So the speed applies, some force multiplied with whether we press forward or backward.
‫So if I extend the speed to, let's say, 200 now, my ball will start to move after a while because
‫200 is enough force for the ball to be moving.
‫But it moves super slowly, as you can see here.
‫All right.
‫And then if I try to go backward or it's too too hard, if I change the mass to one again, now you
‫can see, whoa, the ball is moving super duper fast.
‫And it fell off my screen or my my area.
‫Even so, if I change the mass to one again and my speed to, let's say 50 and let's start the game
‫again.
‫Now my ball will be much, much faster and it will constantly apply force so that the ball will become
‫faster and faster and faster.
‫And that's something that you can change.
‫So you can add and drag to your ball or to your game object so that the speed is limited.
‫So let's add a drag of ten, as you can see.
‫Now, my ball, even if I'm pressing for a long time, it will not exceed a specific speed.
‫So that's the speed that it goes with and it can't go any faster because it has a drag assigned to it.
‫It's the same thing with the angular drag.
‫If I want to change the rotation speed of my object, I could change the angular drag here.
‫Now use gravity.
‫We've seen that.
‫If we activate that, then we use the gravity so our ball can fall off.
‫Or it fall down.
‫As you can see now, it falls down slowly.
‫And if I deactivate the gravity, my ball will stay in the air.
‫As you can see now, it's still in the air.
‫You can see it here even better.
‫Let's use gravity and but we still can move our ball.
‫As you can see, it doesn't apply any gravity, but we can still move the ball.
‫However, if we apply is kinematic, we cannot move the ball anymore.
‫So what is kinetic?
‫Does it will deactivate any kind of movement so it's not influenced by the physics world anymore, which
‫means adding force within our player movement script does not do anything because as I said, it doesn't
‫care about the physics world anymore.
‫All right, so it's kinematic.
‫We can use that for walls if we don't want them to be influenced by physics, but still be walls.
‫So still be a force to reckon with or something that just stops our player or our game object.
‫Then we can use interpolate.
‫As I explained in the last video, that's for the case that you animate your player and you want it
‫to be dependent on the physics world.
‫So that could be important if you use that.
‫So then you could use interpolate or extrapolate.
‫Then the collision detection is discrete by default, which is most of the time completely fine.
‫Continuous dynamic is if you have super fast movement, then you want the collision detection to be
‫extremely fast.
‫Then continuous dynamic is the better choice and otherwise continuous is fine as well.
‫So continuous dynamic is for very, very fast games where physics is very important and goes very quickly.
‫But as I said, discrete is is fine for most of the cases and it's also the best in terms of resources.
‫And finally, let's have a look at constraints.
‫You can freeze positions and freeze rotations.
‫So, for example, if I choose my player and now I move my player to the top and I wanted to not go
‫down, of course I could use use gravity or I can simply activate freeze position y.
‫So now the y position will be frozen and our ball will never fall off.
‫We can still move it, but the y position is simply fixed and we can even activate gravity.
‫It will not influence our ball because the y position is.
‫Fixed or is frozen.
‫Now the same thing goes with the X position.
‫So that means now I can move the ball downwards.
‫Let's activate gravity, but I cannot move it to the right and left.
‫I can only move it backwards and forwards.
‫Same goes with the Z position.
‫So if I activate that and I deactivate the X position now, I can not move forward.
‫Actually, it's not used.
‫It doesn't use gravity.
‫So now I cannot go forward.
‫I can only go to the left and to the right.
‫Same goes with the rotation.
‫So in our case we have this little ball, so or this little player.
‫Let's give him another 3D object which can be, let's say, a cube.
‫So I wanted to have a little cube on top of it and I'm going to make it 0.2 and oh point.
‫Well, actually, let's use one here.
‫Now you can see it better.
‫So now that's our ball.
‫Let's click on the player and let's activate gravity again.
‫So if I move to the left and right, as you can see, it rotates.
‫And now even even flies sometimes, because as you can see, the cube changes the behavior of our ball
‫relatively quickly.
‫And what you can do is freeze the rotation towards X, for example.
‫Now, it will only rotate in a certain direction.
‫Let's freeze the rotation towards Y as well.
‫As you can see, the Y rotation is not influenced anymore, so our ball only rotates towards the z coordinate
‫currently.
‫And if I deactivate that as well now, it will not rotate anymore.
‫It will only move around in our physics world, which might be the behavior that you want to have.
‫So what can happen is if you have an object that could fall off and if you don't have the functionality
‫program that it stands up again, what you can do is freeze rotation so it will never fall down or fall
‫forward or to decide something.
‫So you could freeze rotations for that.
‫All right.
‫So that's about the rigid body.
‫It's really important if you want to impact anything via physics, it needs to have a rigid body, otherwise
‫it won't work.
‫All right.
‫So I'm going to get rid of the cube again.
‫As you can see, you can get some very funny behavior with your ball here, with your player if you
‫add a cube to it or if you change the shape.
‫So please go ahead and play with it and have some fun.
‫And yeah, in the next video we will have a look at the colliders.
‫So there are different types of colliders and we're going to have a look at the most important ones.
‫So see you there, by the way.
‫Don't forget to save your scene.
‫So see you in the next video.