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Welcome.

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In this lecture.

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We're going to take a look at how to create a simple vehicle with suspension.

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I've attached this model to the lecture, so you will want to go ahead and grab it so you can follow

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along with me inside of this vehicle.

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We have a couple of things.

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We have a vehicle seat and inside of this vehicle seat we have some attachments.

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So there's an attachment below the vehicle seat and there's an attachment above the vehicle seat.

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And these are going to be for when our player exits the seat of the vehicle.

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We're either going to teleport them to this top one or this bottom one, depending on if the car is

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flipped or not.

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And the vehicle has a proximity prompt in it as well.

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So we can walk up to the car, activate the proximity prompt and drive the vehicle.

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We have a model here and inside this is just for all of the tires and each tire has an attachment inside

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of it.

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And this attachment is just at the position that's in the directly in the center of our tire.

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And then inside of our body we have an additional five attachments.

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These attachments here are going to be for each of the tires because we're going to be connecting some

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constraints of the attachments and the tires to these attachments here, which include a spring and

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a cylindrical constraint, which we'll use in a little bit.

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And then I have one more attachment here inside of the engine compartment.

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And this just holds some audio, some sound instances that will play when the car starts up and when

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it's driving.

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We're just going to pick a random tire.

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So I'm going to pick this tire right here.

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And with this tire, we're going to create something called a cylindrical constraint right here.

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And this constraint requires two attachments.

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So the first attachment we're going to do is the one that corresponds to this front left tire, which

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is the attachment for the front left tire right here.

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And then the second attachment is going to be the one inside of our tire.

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So we've created a constraint between this attachment and this attachment.

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And what this constraint allows you to do is it allows this part to move in the direction that is defined

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here, which I believe will be forwards and backwards.

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So this constraint allows this tire to only move forwards and backwards an infinite amount of distance.

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Of course, we're going to be using this cylindrical constraint to allow the tire to move only up and

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down a bit to help with the suspension and to limit its movement.

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So I'll just show you how this works real quick.

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But before I do that, I'm going to anchor the body of the car so my car stays up in the air and we'll

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hit play here.

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And there is our cylindrical constraint.

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As you can see, it has moved to the position that was in the attachment for our car.

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But since we're going to be adding suspension later and the tire is going to be moving up and down,

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it won't be teleported in a strange position.

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But as you can see, if I touch the tire, you see it only moves forward and backwards infinitely in

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these directions that are for the cylindrical constraint.

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I can't move it this way.

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I can't move it up or down.

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It can only move forwards and backwards.

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So in order to allow our tire to go up and down instead of forwards and backwards, what we'll need

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to do is to rotate an attachment that is inside of the body.

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So this attachment for our front tire here, we need to rotate this attachment by 90 degrees on the

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Z axis, right?

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So if we go to the orientation of the C frame, if we rotate it by 90 degrees, we should now allow

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our tire to go up and down.

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So if we go and play here.

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You see now our tire has been rotated, but it only goes up and down now.

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Now, the issue here is we need to rotate this tire itself to be vertical instead of horizontal like

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this because a car's tires aren't horizontal.

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Thankfully, that's also easy to do.

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What we need to do is we need to go to the cylindrical constraint.

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And inside of here there's an inclination angle property and we're just going to enter in 90 or representing

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90 degrees.

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And this should rotate the tire for us.

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Now, if we play test here, you see now our tire.

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Is vertical.

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Now there's another issue.

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Our tire is facing inwards.

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We don't want it to face inwards because this is the inside part of the tire and that's the outside

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part of the tire.

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We want this part to be facing this way.

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So again, what we could do is we can go to the attachment that is in the tire and we're going to rotate

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it by 180 degrees.

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So we're just going to flip it all around.

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And again, we can do that on the Z axis.

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We're just going to flip the tire entirely like that.

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So as you can see, our attachment has been flipped.

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And if we go and play, test it again.

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As you can see, our tire is now facing in the proper direction.

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Now, the next thing we need to do for our tire is we need to constrain its movements, because right

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now it's going to go an infinite direction, upwards or downwards because there's no limit set on this

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cylindrical constraint.

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So in order to set a limit on our cylindrical constraint, there is a property in here and this property

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is limits enabled.

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So when I enable this property, you should see this bar appear and it's telling us what the limit is

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going to be for our tire.

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So we have a lower limit and an upper limit right now.

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We don't want it to be at an upper limit of five.

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So what I'm going to do is I'm going to set the lower limit.

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I'm going to set this to -1.5, and that's -1.5 studs from this attachment.

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And then the upper limit, I'm going to set to be -0.3.

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So -0.3 studs from this attachment will be right here.

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Now, the reason I'm doing this is because I don't want the tire to move above this attachment because

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that means the attachment inside of the tire would go above this attachment.

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And when that happens, well, we're going to be adding a spring.

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Once this attachment goes above this attachment, the spring is going to flip around and the spring

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is going to apply force this way.

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But we only want the spring to apply force in this direction, right?

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So we have to constrain how far up we can move the tire.

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We don't want it to go above this attachment.

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And here I've allowed the tire to go down a little bit more as well, just, you know, to have a tire

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hang out when we're in the air.

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Now, another thing I will note for the tires is I've enabled a property in here called Custom Physical

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Properties.

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And in here it allows me to change several things about this part.

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It allows me to change the density or how much mass the part has.

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It allows me to change the elasticity, which just kind of determines how much the part will bounce

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around when it hits something.

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It allows me to change the friction.

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And of course we want to have a high friction.

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I've increased the density of the tire to give it some more mass, and I've also increased the friction

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and reduce the elasticity.

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So if you ever wanted your car to drift more, then of course you'd want to reduce the friction that

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I've set here.

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But I've set it to 1.2 for all the tires.

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Now the last thing we need to do for our tires, we need to create a spring attachment.

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Or a spring constraint.

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And inside of the spring constraint, again, two attachments.

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We're going to first select the one that is in the car, which is going to be attachment for our front

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tire and the left, and then the attachment that is inside of our tire.

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And as you can see, it has created this spring constraint.

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And like I was talking about earlier, we don't want this part to go above this part because that means

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our spring right here is going to flip and it's going to be exerting force in the wrong direction.

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We don't want to do that.

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So in our spring constraint, we need to change some properties.

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We see we have some right here.

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We have one called dampening or damping.

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And damping is used to kind of reduce or dampen and soften the force that is applied by the spring.

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So typically a spring likes to go back to its resting state or its free length, which is one stud long.

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So if I stretch the spring beyond one stud or I compress it below one stud, it's going to exert a force

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to try to get back to that.

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Free length and dampening allows us to soften that force out.

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So instead of it being super springy, it's more gentle.

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It kind of goes out slower.

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So for this vehicle, I'm going to set the damping to be around 400.

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Now for the free length, I want the spring to have a bit of room to stretch out.

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So I would say the resting length of our spring should be probably around 2.5 studs, which you see

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indicated by these blue arrows.

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So our tire will push the car up a little bit.

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Now for the stiffness.

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This is going to be the amount of force that the spring is going to exert to try to get back to its

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free length.

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And these numbers are kind of arbitrary.

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They're just kind of, you know, represent a higher number, more force.

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But for this vehicle, a stiffness of around 5500 works pretty good.

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Now, if we actually go and play test the game, you'll see the spring is going to stretch out to its

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free length.

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And as you can see, our tire is hanging here.

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Now, if the car falls down and compresses on the spring, the spring is going to and exert a force

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back to resist the gravity or weight of the car, which is going to push the car up.

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If we had a stiffness that was too weak, then the spring would get compressed too much.

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So that's why I thought 5500 was pretty good for this vehicle.

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But of course you can go ahead and tweak it to however you like.

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But now that we have all of this set up for this tire, there's one more thing we need to do.

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And we need to stop this tire from colliding with the body.

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Since this body is a mesh, the collision in the body is not exactly perfect.

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So this tire is going to be colliding with the body when it tries to go up and down with the spring.

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So an easy way to fix this would not to be using collision groups, but there's a constraint we can

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use called no collision constraint, which allows you to select two parts for them not to collide with

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each other.

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So we can select the tire and we don't want the tire to collide with the body just like that.

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Now that we've got the setup for this first hire, we need to do it for the rest of our tires.

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So what I'm going to do is I'm going to copy all of these constraints and I'm going to paste it into

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this one.

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And what we're going to have to do is change the attachments in here.

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So for this attachment, we need to do the front right tire and the attachment is going to be the one

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inside of this tire.

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For our no collusion constraint.

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We need to select the front right tire and for the spring we need to do the same thing.

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This is the front right tire attached to the attachment inside of the tire.

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Now, we also need to make sure that we rotate the same thing here inside of this attachment.

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So we did 180 degrees for this one.

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We also need to do 180 degrees for this one as well.

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And then we also need to rotate this attachment in here, which was by 90 degrees.

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Again.

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We'll do the same thing for the rear left tire.

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We're going to select rear tire.

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The attachment inside of the rear left tire for the collision again, rear left tire and then rear left

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tire and the attachment inside of the tire.

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Once more.

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For this one, we'll just select for the rear right tire attachment in here.

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Pick this tire and then again, the attachment for the rear.

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And for this attachment.

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Perfect.

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So now we should have all of our tires set up.

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And in order to make sure we confirm this is working, we can go and play a test real quick.

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All right.

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So you should be noticing a couple issues here.

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These tires are looking a little wonky and we'll go ahead and have to fix that real quick.

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Because we forgot to rotate these attachments.

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So again, you have to rotate it by 180 degrees on these two attachments.

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And then for the attachments and the tire.

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Remember, we have to do 90 degrees.

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Now if we play test again.

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You should notice one more thing and you will see that these tires here are rotated correctly, but

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these tires are not.

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And that's because I had to copy and paste one of these tires and use them for the rest, which means

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I had to rotate one of them.

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So they're being flipped in the wrong direction.

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And an easy way to fix that would to be to just select these two tires.

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And for the attachments in them.

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We just need to undo that 180 degree rotation that flipped them around.

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So one more time if we play test.

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You will see that all of our tires are facing the correct direction.

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And that also means if I go to an anchor, the body of the car just like so.

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You will now see that our tires are holding up the car.

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But it's been a little weird.

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I think there's some problems with the physics because I'm recording and it's trying to calculate physics

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at the same time, but I think it's figured itself out.

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But as you can see now, we have suspension on our vehicle.

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And if I jump on the vehicle, you can see the suspension working there.

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So I'm hopping on my vehicle and you can see our car has some nice suspension.

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Now we need to do another thing inside of all of our cylindrical constraints.

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I'm going to select all of them.

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We have to change something in here called angular actuator type.

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And this is going to allow us to rotate the tires and allow the car to drive.

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So that means we need to set this actuator type to motor.

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And when you do this, you should see all of these blue arrows show up and it's telling us the direction

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that the tires will rotate when we apply a positive force on the tire.

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So and here we get a few more properties, we get an angular velocity.

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The velocity of the rotation of our tire and then the torque for the motor that's rotating our tire.

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Of course we're going to need some torque.

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If we don't, it's going to take forever to rotate the tires.

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So as an example, I'm going to set this to 4000 and I'm just going to run the server.

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And inside of our tires.

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What I'll do for each of these cylindrical constraints.

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Is that I'm going to apply some force here.

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So I'm going to increase the angular velocity to ten.

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And as you can see, all of the tires on our car start rotating.

229
00:15:11,770 --> 00:15:15,310
But if I reduce the torque to something, let's say ten.

230
00:15:16,440 --> 00:15:20,430
And then I set the angular velocity to zero.

231
00:15:20,460 --> 00:15:27,090
You'll see that the tires take a long time to stop because we have very little torque.

232
00:15:28,900 --> 00:15:34,750
But now that they've stopped, if I keep the torque low actually at like ten and then I try to apply

233
00:15:34,750 --> 00:15:37,330
some velocity that's hires like 100.

234
00:15:38,030 --> 00:15:41,450
You see, it takes a very long time for them to go.

235
00:15:41,450 --> 00:15:43,280
And that's because we don't have much talk here.

236
00:15:44,570 --> 00:15:53,150
But if I set the talk to something like 5000, we're able to speed up these tires a lot faster, basically

237
00:15:53,150 --> 00:15:54,890
instantly, because we have more torque.

238
00:15:55,370 --> 00:16:00,520
And in order to have our vehicle drive around and pull itself up mountains, we need more torque.

239
00:16:00,530 --> 00:16:06,080
So for this vehicle in particular, I found that a torque of around 7000 should work just fine.

240
00:16:07,980 --> 00:16:13,470
So I'm going to stop the test and I'm going to reset these talks back to zero, because now is the time

241
00:16:13,470 --> 00:16:15,510
we can start scripting our car.

242
00:16:16,870 --> 00:16:21,140
What I'm going to do is I'm going to create a new script inside of the vehicle seat.

243
00:16:21,800 --> 00:16:28,990
We can just name this script, something like vehicle script and the script.

244
00:16:29,000 --> 00:16:30,710
We're going to need a few things.

245
00:16:30,710 --> 00:16:32,630
We're going to need some services.

246
00:16:32,780 --> 00:16:36,170
So we'll just need between service in this case.

247
00:16:38,780 --> 00:16:41,060
And then we'll need some variables.

248
00:16:41,330 --> 00:16:44,330
One, we need to store the car, which is easy.

249
00:16:44,330 --> 00:16:50,060
It's just going to be script dot parent, dot parent.

250
00:16:50,330 --> 00:16:51,410
Actually, you know what?

251
00:16:51,410 --> 00:16:53,720
I'll just put the script directly in the car instead.

252
00:16:54,290 --> 00:16:56,150
So that way it's just script dot parent.

253
00:16:56,150 --> 00:16:57,350
We'll just do that instead.

254
00:16:58,370 --> 00:17:01,700
Next, we need to reference the model for the tires.

255
00:17:01,700 --> 00:17:04,430
So that'll just be car tires.

256
00:17:06,180 --> 00:17:12,450
And then since we want the car to drive, we're going to need to reference all of the cylindrical constraints

257
00:17:12,450 --> 00:17:17,460
inside of each tire so we can apply a velocity in here to get the car moving.

258
00:17:17,760 --> 00:17:19,440
So we'll just reference each one.

259
00:17:19,440 --> 00:17:22,890
We'll do cyl cylindrical.

260
00:17:24,780 --> 00:17:28,020
And we'll do front left equal to tires.

261
00:17:28,020 --> 00:17:30,930
Dot front l dot cylindrical constraint.

262
00:17:32,250 --> 00:17:36,090
Do the same thing for the front, right?

263
00:17:41,650 --> 00:17:43,810
We'll do one for the rear as well.

264
00:17:43,810 --> 00:17:47,410
So we'll do rear left equal two tires.

265
00:17:47,770 --> 00:17:49,440
Rear left.

266
00:17:49,870 --> 00:17:54,340
Cylindrical constraint and then cylindrical.

267
00:17:54,940 --> 00:17:55,630
Oops.

268
00:18:04,840 --> 00:18:05,530
There we go.

269
00:18:05,740 --> 00:18:08,280
Cylindrical rear right.

270
00:18:08,290 --> 00:18:13,150
Equal tires dot rear dot, cylindrical constraint.

271
00:18:14,310 --> 00:18:18,900
Then I'll create a reference to the seat in the car, which is just car dot.

272
00:18:18,900 --> 00:18:20,310
Vehicle seat.

273
00:18:22,060 --> 00:18:28,510
I'll create a reference to the prompt in the seat that's equal to seat dot proximity prompt.

274
00:18:28,660 --> 00:18:32,920
And then I'm going to keep track of who is currently sitting in the seat.

275
00:18:33,010 --> 00:18:34,990
We'll just call it current occupant.

276
00:18:35,080 --> 00:18:36,130
Set it to nil.

277
00:18:37,520 --> 00:18:40,640
And then we'll need to reference the sounds that are in the vehicle.

278
00:18:40,640 --> 00:18:43,400
So we'll do one for the idle sound.

279
00:18:43,430 --> 00:18:45,380
It's going to be in the car.

280
00:18:45,470 --> 00:18:51,440
We get the body of the car and there's an attachment in there called engine sounds and we'll get the

281
00:18:51,440 --> 00:18:55,970
car idle sound and then we'll have the start sound as well.

282
00:19:00,630 --> 00:19:01,140
Okay.

283
00:19:01,350 --> 00:19:03,840
And then we'll need some constants.

284
00:19:04,340 --> 00:19:08,130
And these constants are going to define some limitations on our vehicle.

285
00:19:08,490 --> 00:19:13,750
So the first limitation we need to define is the max angular velocity.

286
00:19:13,770 --> 00:19:18,520
So what's the max velocity that we want to apply for the tires?

287
00:19:18,540 --> 00:19:24,570
And we can do this by checking to see what the max speed property is here in our seat.

288
00:19:25,020 --> 00:19:29,780
And inside I've set the max speed to be 65 or 65, I believe Studs.

289
00:19:29,790 --> 00:19:32,610
I think it's 65 studs per second, if I'm correct.

290
00:19:32,910 --> 00:19:36,770
And I also set the torque that we'll use for the vehicle as well.

291
00:19:36,780 --> 00:19:43,290
But in order to calculate the max angular velocity, we need to get the seats dot max speed.

292
00:19:44,110 --> 00:19:51,610
And we need to divide it by the radius of one of the tires so that way we can get the max angular velocity.

293
00:19:52,320 --> 00:19:54,930
So it's easy to get one of the radius of the tires.

294
00:19:54,930 --> 00:19:56,610
We just need to grab one.

295
00:19:56,610 --> 00:19:58,340
We'll just do tires, Dot.

296
00:19:58,530 --> 00:19:59,940
Let's just do front left.

297
00:20:00,210 --> 00:20:10,080
We'll get the size of it in the y axis and that's going to be the total width of our tire.

298
00:20:10,080 --> 00:20:12,600
But we want the radius, which is half of the total width.

299
00:20:12,600 --> 00:20:17,310
So we'll just divide it by two and we'll get our max angular velocity to make sure that we don't go

300
00:20:17,310 --> 00:20:18,720
above this max speed.

301
00:20:20,470 --> 00:20:24,370
Next, we need to set a constant for defining.

302
00:20:25,170 --> 00:20:28,500
How far we want the tires on the front to rotate when we're steering.

303
00:20:28,500 --> 00:20:34,590
So the max rotation will have is 35 degrees, so the tires will rotate 35 degrees to the left or to

304
00:20:34,590 --> 00:20:36,240
the right to turn either left or right.

305
00:20:37,740 --> 00:20:42,420
And then we needed to define a constant for our ideal sound.

306
00:20:42,690 --> 00:20:47,910
So my plan is, is that when we're driving the car, when the car goes faster and faster, we're going

307
00:20:47,910 --> 00:20:54,330
to set the playback speed of our car idle sound to be higher and higher, which makes it sound like,

308
00:20:54,330 --> 00:20:56,190
you know, the car is driving faster and faster.

309
00:20:56,190 --> 00:20:57,530
It's having higher RPM.

310
00:20:57,540 --> 00:21:01,950
But when the car is not moving, we still want the idle sound to be playing, which is why we need a

311
00:21:01,950 --> 00:21:04,560
minimum playback sound for when we're idling.

312
00:21:05,880 --> 00:21:09,390
And that's going to be a playback speed of, let's say, 0.6.

313
00:21:10,810 --> 00:21:14,440
One more constant is going to be called rotation duration.

314
00:21:14,470 --> 00:21:15,430
What is this for?

315
00:21:15,790 --> 00:21:21,460
So when we turn the steering wheel to go left or right, how long do we want it to take for the tires

316
00:21:21,460 --> 00:21:23,260
to rotate either left or right?

317
00:21:23,890 --> 00:21:28,330
And I found that about 0.4 seconds would be good for that.

318
00:21:29,180 --> 00:21:32,540
Next thing we need to do is define one function.

319
00:21:32,660 --> 00:21:38,550
And this function is going to be for updating the playback speed of our idle sound.

320
00:21:38,570 --> 00:21:40,130
I'll just call it update audio.

321
00:21:42,060 --> 00:21:45,210
And then we'll need to listen to some events.

322
00:21:46,000 --> 00:21:51,550
Well, first off, we need to listen to when our prompt gets triggered because a player wants to enter

323
00:21:51,550 --> 00:21:52,450
the vehicle.

324
00:21:53,110 --> 00:21:57,400
We need to listen to when a property in the seat changes.

325
00:21:57,400 --> 00:21:58,930
That's called occupant.

326
00:21:59,140 --> 00:22:04,570
So the vehicle seat has a property in here that tells us who the occupant of our seat is.

327
00:22:04,570 --> 00:22:05,830
Where is that at?

328
00:22:06,530 --> 00:22:07,300
Here it is right here.

329
00:22:07,310 --> 00:22:13,340
Occupant So whenever a player goes into the seat, it'll tell us the humanoid of that player so we can

330
00:22:13,340 --> 00:22:14,360
get the occupant.

331
00:22:14,720 --> 00:22:17,270
So we'll get property change signal.

332
00:22:18,100 --> 00:22:19,480
That's going to be occupant.

333
00:22:20,570 --> 00:22:26,270
And when that property changes, we are going to do some stuff in there.

334
00:22:26,870 --> 00:22:31,640
We also need to listen to when a property in the seat called steer changes.

335
00:22:31,640 --> 00:22:34,730
So get property change signal steer.

336
00:22:36,390 --> 00:22:42,870
And what this does is that if we turn left, the steer property turns to the number one.

337
00:22:42,900 --> 00:22:45,370
If we steer to the right, it turns to negative one.

338
00:22:45,370 --> 00:22:47,370
And if we don't steer at all, it's zero.

339
00:22:47,520 --> 00:22:49,620
So we need to pay attention to that.

340
00:22:49,830 --> 00:22:55,470
And we also need to pay attention to when the player presses on the gas to either go backwards or forwards

341
00:22:55,620 --> 00:22:58,920
so we can do seat jet property change signal.

342
00:22:58,920 --> 00:23:00,990
And this property is called throttle.

343
00:23:02,480 --> 00:23:06,260
So if we go forwards, it's a positive number of one.

344
00:23:06,260 --> 00:23:08,480
If we go backwards, it's negative one.

345
00:23:08,480 --> 00:23:10,340
If we don't move at all, it's zero.

346
00:23:10,490 --> 00:23:12,590
So we'll connect a function to that as well.

347
00:23:14,390 --> 00:23:15,800
And that's all we need to do.

348
00:23:15,920 --> 00:23:21,980
So what we can first fill out is the event for when our prompt gets triggered by a player.

349
00:23:22,160 --> 00:23:28,280
So what we want to do is we first want to check is if there's already someone sitting in our vehicle.

350
00:23:28,310 --> 00:23:33,060
So if our seat already has an occupant, then we'll just return, right?

351
00:23:33,080 --> 00:23:35,060
You can't have two drivers of a car.

352
00:23:35,850 --> 00:23:41,820
The next thing we want to check for is if the player who activated this prompt has a character model.

353
00:23:41,850 --> 00:23:46,410
Because if they don't, well, we don't want to put them in the seat.

354
00:23:46,410 --> 00:23:52,680
And exploiters can also fire prompts, even if they don't have a character or anything, they can just

355
00:23:52,680 --> 00:23:54,190
fire them whenever they want.

356
00:23:54,210 --> 00:23:56,160
So we got to make sure we stop that.

357
00:23:56,310 --> 00:24:01,980
So if this player doesn't have a character, so if not player dot character, then we'll just return

358
00:24:01,980 --> 00:24:02,550
as well.

359
00:24:04,580 --> 00:24:09,810
Otherwise we can use a function on our C and it's called sit.

360
00:24:09,830 --> 00:24:15,110
And what we do is we pass a humanoid to this function and it forces them to sit in the car seat.

361
00:24:15,110 --> 00:24:18,620
In this case, that's going to be the player's character humanoid.

362
00:24:19,400 --> 00:24:23,750
So now we are forcing the player to sit in the seat and that's all we need to do there.

363
00:24:24,380 --> 00:24:28,090
But next, we need to listen for when that occupant property gets updated.

364
00:24:28,100 --> 00:24:31,610
Because when we force the player to sit, then it's going to update this property.

365
00:24:31,610 --> 00:24:32,690
So what do we want to do?

366
00:24:32,900 --> 00:24:39,590
Well, we want to listen If the seat gets an occupant so we get a new occupant, then what we want to

367
00:24:39,590 --> 00:24:44,360
do is we want to set that variable of current occupant to the seat dot occupant.

368
00:24:45,520 --> 00:24:49,570
We want to disable the prompt so nobody else can enter the vehicle.

369
00:24:50,960 --> 00:24:55,130
And when the player enters the vehicle, we want to play the ignition sound.

370
00:24:55,220 --> 00:24:56,360
So the car is starting up.

371
00:24:56,360 --> 00:24:57,710
So we'll play that sound.

372
00:24:59,070 --> 00:25:03,570
And I don't want the car to idle right away because we have to get past that ignition.

373
00:25:03,570 --> 00:25:10,650
So I'll just wait like two seconds, because if we go to our sound here, that is inside of our body.

374
00:25:15,070 --> 00:25:17,770
We have to wait about two seconds before the car starts idling.

375
00:25:17,770 --> 00:25:18,790
So we'll wait for that.

376
00:25:20,110 --> 00:25:26,560
And then once those two seconds are up, then we can start playing the Idol sound, which is set to

377
00:25:26,560 --> 00:25:28,540
loop forever until we stop the sound.

378
00:25:28,690 --> 00:25:33,940
However, after we wait for these two seconds, there could be a chance that the player sits down and

379
00:25:33,940 --> 00:25:35,200
then immediately sits back up.

380
00:25:35,200 --> 00:25:37,810
And we don't want to play the idol sound if there's no occupant.

381
00:25:37,810 --> 00:25:44,080
So after we wait for two seconds, we still need to make sure there is a seat occupant if there isn't.

382
00:25:44,910 --> 00:25:45,920
Then we'll just return.

383
00:25:45,920 --> 00:25:47,180
We don't need to play the sound.

384
00:25:48,400 --> 00:25:50,470
So we'll do idle play.

385
00:25:51,100 --> 00:25:55,960
And then once we start playing the idling sound, that's when we need to start updating the audio for

386
00:25:55,960 --> 00:25:56,800
our idling sound.

387
00:25:56,800 --> 00:25:58,750
So that's why we'll call this function here.

388
00:25:59,650 --> 00:26:01,300
So what's this function going to do?

389
00:26:01,330 --> 00:26:04,750
Well, this function is going to loop for us.

390
00:26:04,780 --> 00:26:06,730
So while we have an occupant.

391
00:26:06,730 --> 00:26:09,100
So while seat occupant is true.

392
00:26:10,020 --> 00:26:16,860
Then what we're going to do is we're going to set the playback speed of our idle sound equal to this.

393
00:26:16,890 --> 00:26:23,430
We're going to call the math.max function and we're going to pass minimum playback speed.

394
00:26:24,820 --> 00:26:25,150
Actually.

395
00:26:25,150 --> 00:26:26,710
Why did I name it sound?

396
00:26:27,480 --> 00:26:28,320
Should be Speed.

397
00:26:29,010 --> 00:26:29,430
Minimum.

398
00:26:29,430 --> 00:26:30,180
Playback.

399
00:26:30,180 --> 00:26:30,750
Speed.

400
00:26:32,190 --> 00:26:33,900
So minimum playback speed.

401
00:26:35,040 --> 00:26:39,290
In case the second number we pass goes below the minimum playback speed.

402
00:26:39,290 --> 00:26:46,430
We're guaranteed to have a playback speed of at least 0.6 because if it goes to like 0.1 or 0 or negative

403
00:26:46,430 --> 00:26:52,400
or whatever, this gets the maximum number and this will always be the max if the second number goes

404
00:26:52,400 --> 00:26:53,060
below it.

405
00:26:53,510 --> 00:26:55,370
So what is the second number going to be?

406
00:26:55,400 --> 00:27:00,660
Well, it's going to be the minimum playback speed, but we're going to multiply it by this.

407
00:27:00,680 --> 00:27:07,400
We're going to multiply it by the cars primary part, which is the body of the car inside of the model.

408
00:27:07,400 --> 00:27:14,330
I set the primary part to be the body and this body, since it has all of this stuff attached to it.

409
00:27:14,420 --> 00:27:16,100
It's called an assembly.

410
00:27:16,610 --> 00:27:19,360
And this assembly has a velocity.

411
00:27:19,370 --> 00:27:24,710
So when it's moving, the game is like, hey, this has this has a velocity in a specific direction.

412
00:27:25,040 --> 00:27:28,730
And from that we can calculate how fast the car is moving.

413
00:27:28,850 --> 00:27:35,550
So we can get the assembly linear velocity and we can get the magnitude of this velocity.

414
00:27:35,550 --> 00:27:42,150
So it just returns to us a number that represents how far out this velocity is.

415
00:27:42,150 --> 00:27:44,130
How big is this vector?

416
00:27:44,160 --> 00:27:49,070
Because if we're only moving at like one stud per second, then this vector is going to be super tiny.

417
00:27:49,080 --> 00:27:53,190
Our magnitude is going to be small, but if we're moving at like 50 studs per second, then it's going

418
00:27:53,190 --> 00:27:56,040
to be a larger magnitude, which means we're going faster.

419
00:27:56,040 --> 00:28:00,270
And that means we have to increase the playback speed of our idling sound.

420
00:28:01,040 --> 00:28:04,610
But let's say we're we are moving 55 studs per second.

421
00:28:04,610 --> 00:28:07,310
That's going to return a value of like 55 here.

422
00:28:07,310 --> 00:28:13,160
And if we multiply 55 by our 0.6, we're going to get a playback speed of like 20 something, which

423
00:28:13,160 --> 00:28:14,320
is way too fast.

424
00:28:14,330 --> 00:28:18,680
So we need to reduce this number down a lot, but by not too much.

425
00:28:18,950 --> 00:28:24,320
And if we divide it by 20, that should give us a pretty good number for our playback speed.

426
00:28:24,350 --> 00:28:31,340
Of course you can mess with this magic number to, you know, adjust how how fast you want the playback

427
00:28:31,340 --> 00:28:33,140
speed of our audio to be while we're driving.

428
00:28:33,140 --> 00:28:34,940
But I found 20 to be pretty good.

429
00:28:36,210 --> 00:28:43,740
And of course, since we're in a while loop, we need to yield and we'll yield 4.05 seconds.

430
00:28:43,740 --> 00:28:49,710
So this will update the playback speed of our sound every 0.5 or 0.0 five seconds.

431
00:28:50,570 --> 00:28:51,020
Anyway.

432
00:28:51,020 --> 00:28:56,450
So once we've got all that done and there's a player in the seat, whenever they, you know, press

433
00:28:56,450 --> 00:29:00,020
A or D on their key, it's going to update this steer property.

434
00:29:00,020 --> 00:29:06,170
And that means we want to steer the front tires In order to steer the front tires, we need to rotate

435
00:29:06,170 --> 00:29:07,070
those attachments.

436
00:29:07,070 --> 00:29:10,400
That's in the tire because it's using that cylindrical constraint.

437
00:29:10,400 --> 00:29:14,560
If I rotate the attachment in the tire, then it'll rotate the tire itself.

438
00:29:14,570 --> 00:29:20,420
So we need to calculate an orientation and it's going to be a new vector three.

439
00:29:21,010 --> 00:29:27,790
We don't need to rotate it on the x axis, but we need to rotate it on the vertical y axis and we're

440
00:29:27,790 --> 00:29:29,490
going to rotate it by.

441
00:29:29,500 --> 00:29:38,500
We're going to get the seat dot steer, which is either going to be negative one, 1 or 0, and we're

442
00:29:38,500 --> 00:29:41,980
going to multiply it by the max tire rotation.

443
00:29:42,190 --> 00:29:46,450
So if we're not steering, it's zero, then we're not going to rotate the tire at all.

444
00:29:46,690 --> 00:29:53,140
If it's negative one, we multiply this and rotate it in the other direction, but it's actually going

445
00:29:53,140 --> 00:29:55,450
to rotate in the opposite direction.

446
00:29:55,450 --> 00:29:58,450
So if we press A, it's going to rotate to the right.

447
00:29:58,450 --> 00:30:01,510
And if we press D on our keyboard, it's going to rotate to the left.

448
00:30:01,510 --> 00:30:06,430
So I'm going to make sure to negate the posterior value.

449
00:30:07,950 --> 00:30:10,610
And then for the Z is very important.

450
00:30:10,620 --> 00:30:16,080
Remember that the attachments that are inside of our tires are actually excuse me, we're rotating,

451
00:30:16,110 --> 00:30:19,920
not the attachment on our tires, but we're actually rotating the attachment in the body.

452
00:30:20,880 --> 00:30:22,230
Let me just correct that real quick.

453
00:30:22,260 --> 00:30:26,580
We're rotating these attachments to rotate our tires and not the ones in here.

454
00:30:27,410 --> 00:30:32,990
And we need to remember that each of these attachments, we've already rotated them by 90 degrees on

455
00:30:32,990 --> 00:30:33,660
the Z axis.

456
00:30:33,660 --> 00:30:34,960
So we've got to make sure we include that.

457
00:30:34,970 --> 00:30:36,170
We don't want that to change.

458
00:30:38,010 --> 00:30:42,450
But since we've applied this orientation, that means we can rotate the tires.

459
00:30:42,450 --> 00:30:48,510
But I don't want to rotate the tires instantly and said I want them to slowly move to that position

460
00:30:48,510 --> 00:30:50,270
based on this rotation duration.

461
00:30:50,280 --> 00:30:52,230
And that's where the tween service comes in.

462
00:30:52,470 --> 00:30:54,750
So we're going to create two new tweens.

463
00:30:54,750 --> 00:31:01,260
We're going to do tween service and we're going to create a tween on what we're going to get the body

464
00:31:01,260 --> 00:31:04,770
and we're going to get the front attachment for one of the tires.

465
00:31:04,770 --> 00:31:08,760
So first we'll do front attachment for the left tire.

466
00:31:10,130 --> 00:31:12,260
We're going to create a new tween info.

467
00:31:13,100 --> 00:31:18,680
And inside there, we're just going to have the rotation duration and what do we want to tween We want

468
00:31:18,680 --> 00:31:24,740
to tween the orientation of our attachment, which is going to be equal to the orientation that we just

469
00:31:24,740 --> 00:31:25,910
created right here.

470
00:31:26,560 --> 00:31:33,070
And of course, since this create function in our tween service going to return to us a track, we can

471
00:31:33,070 --> 00:31:34,120
play it right here.

472
00:31:34,120 --> 00:31:38,770
We can just call play and we don't need to store the return from this function in a variable.

473
00:31:39,670 --> 00:31:42,310
And then we can just copy this.

474
00:31:44,050 --> 00:31:47,680
And do the exact same thing, but for the front right tyre.

475
00:31:48,510 --> 00:31:49,800
Just like that.

476
00:31:50,860 --> 00:31:53,860
So what we can do is we can test what we've got done so far.

477
00:31:53,860 --> 00:31:55,780
And if I go and play here.

478
00:31:57,450 --> 00:31:59,040
You see if I hop in my vehicle.

479
00:32:01,750 --> 00:32:04,420
We get the start ignition sound and then we get the idling sound.

480
00:32:04,420 --> 00:32:12,640
And if I press A on my keyboard, the tires tween to the left, if I let go of a they tween to be neutral,

481
00:32:12,640 --> 00:32:16,120
and if I press de they tween to the right.

482
00:32:16,120 --> 00:32:17,110
So very cool.

483
00:32:18,720 --> 00:32:21,480
Inside of this function here.

484
00:32:21,600 --> 00:32:25,290
We need to listen for when we press down on the throttle.

485
00:32:25,740 --> 00:32:32,910
So the very first thing we need to do is we need to set the torque in all of our cylindrical constraints

486
00:32:32,910 --> 00:32:35,960
to the torque that has been defined in our vehicle seat.

487
00:32:37,420 --> 00:32:38,980
And that's going to be easy.

488
00:32:39,010 --> 00:32:41,620
We just need to create a reference to that value.

489
00:32:43,000 --> 00:32:44,890
Equal to stalk.

490
00:32:45,940 --> 00:32:51,220
And then for every single one of these cylindrical constraints that we've referenced up here, we just

491
00:32:51,220 --> 00:32:52,600
need to set the torque to that.

492
00:32:52,600 --> 00:32:53,500
So.

493
00:32:54,670 --> 00:32:56,470
Cylindrical.

494
00:32:56,470 --> 00:32:56,950
Right.

495
00:32:56,950 --> 00:32:58,480
Left stalk.

496
00:32:59,300 --> 00:33:02,090
Or I believe it is motor max torque.

497
00:33:02,090 --> 00:33:03,440
We're just setting it to talk.

498
00:33:03,470 --> 00:33:06,020
Do it again for the.

499
00:33:07,570 --> 00:33:07,990
Rear.

500
00:33:08,020 --> 00:33:08,800
Right.

501
00:33:11,900 --> 00:33:12,980
Do it again.

502
00:33:16,080 --> 00:33:18,000
It looks like I misspelled that one.

503
00:33:18,840 --> 00:33:19,660
So.

504
00:33:19,710 --> 00:33:23,210
Rent, cylindrical, cylindrical.

505
00:33:23,490 --> 00:33:24,090
There we go.

506
00:33:25,340 --> 00:33:26,360
We'll fix that right here.

507
00:33:27,970 --> 00:33:31,090
And then we need to do this for the front.

508
00:33:31,090 --> 00:33:35,950
So we'll do front right motor max torque equal to torque.

509
00:33:37,200 --> 00:33:41,010
And then we need to do the last one for the front left.

510
00:33:47,530 --> 00:33:50,940
Now that we've set the torque, that means we can start to rotate our tires.

511
00:33:50,950 --> 00:33:56,610
And that means we need to calculate the correct angular velocity for the tires.

512
00:33:56,620 --> 00:33:57,880
How do we do that?

513
00:33:58,180 --> 00:33:59,410
It's going to be pretty simple.

514
00:33:59,410 --> 00:34:02,740
We can just create a variable, call it angular velocity.

515
00:34:03,600 --> 00:34:09,650
And we're going to set it equal to the seats throttle, which is either going to be negative one, 0

516
00:34:09,650 --> 00:34:10,830
or 1.

517
00:34:11,220 --> 00:34:14,490
And we just multiply it by our max angular velocity.

518
00:34:14,670 --> 00:34:19,510
So if we want to go forward, it's going to be one times the max angular velocity.

519
00:34:19,530 --> 00:34:23,460
If we're going backwards, this number will be negative and that means the tires are going to rotate

520
00:34:23,460 --> 00:34:23,970
the other way.

521
00:34:23,970 --> 00:34:25,140
So we go backwards.

522
00:34:25,380 --> 00:34:29,040
And if it's zero, then we have no angular velocity at all.

523
00:34:29,190 --> 00:34:30,160
Pretty easy.

524
00:34:30,210 --> 00:34:32,340
So then we can just copy this.

525
00:34:33,310 --> 00:34:36,020
And we're going to set it to this angular velocity.

526
00:34:36,040 --> 00:34:36,860
Copy that.

527
00:34:36,860 --> 00:34:38,440
And just paste them all here.

528
00:34:39,300 --> 00:34:41,610
And we need to set that in the.

529
00:34:42,410 --> 00:34:44,590
And your velocity property.

530
00:34:46,230 --> 00:34:50,270
Just copy that and paste it there, paste it there and paste it there.

531
00:34:50,280 --> 00:34:51,190
Very cool.

532
00:34:51,210 --> 00:34:53,730
So now if we go and play again.

533
00:34:57,920 --> 00:35:01,790
If I press a W, our tires should start rotating forwards.

534
00:35:02,360 --> 00:35:02,720
There we go.

535
00:35:02,720 --> 00:35:03,620
They're rotating forwards.

536
00:35:03,620 --> 00:35:05,180
I let go of w they stopped.

537
00:35:05,180 --> 00:35:10,370
If I press s, they rotate backwards and I release s and we're all good to go.

538
00:35:10,550 --> 00:35:11,240
Very cool.

539
00:35:11,660 --> 00:35:18,290
So the next thing we need to do is when the player jumps up out of the seat, we need to either put

540
00:35:18,290 --> 00:35:24,200
them at the position of this exit attachment at the bottom of the car or the top of the car, because

541
00:35:24,200 --> 00:35:30,110
if the car is flipped over, we need to set their position to be on this bottom attachment.

542
00:35:30,440 --> 00:35:33,200
Well, we can go back to this property here.

543
00:35:34,360 --> 00:35:35,800
And we're going to listen.

544
00:35:35,800 --> 00:35:41,800
So when this occupant property changes and there is no occupant, meaning the last player who was ever

545
00:35:41,800 --> 00:35:44,050
in the vehicle jumped out of the seat.

546
00:35:44,080 --> 00:35:48,730
What we need to do is we need to check if there was a current occupant that was last sitting in the

547
00:35:48,730 --> 00:35:50,050
car, if there was.

548
00:35:50,770 --> 00:35:55,720
Then we need to figure out which attachment we need to teleport their torso to.

549
00:35:55,870 --> 00:35:59,050
So I'll just create a variable called exit attachment.

550
00:36:00,010 --> 00:36:07,420
And then what we could do is we can check if the seat dot attachment exit top, we're going to get the

551
00:36:07,420 --> 00:36:10,270
world keyframe the position of that attachment in the world.

552
00:36:12,120 --> 00:36:13,050
And get its y axis.

553
00:36:13,050 --> 00:36:17,970
And we're going to check if this y axis is above the other attachment.

554
00:36:17,970 --> 00:36:23,700
So attachment exit bottom world C frame dot position dot y.

555
00:36:24,360 --> 00:36:30,990
So if this attachment is above our bottom attachment, meaning our car isn't flipped over.

556
00:36:32,400 --> 00:36:37,470
Then our exit attachment is just going to be equal to that attachment exit top.

557
00:36:37,530 --> 00:36:45,780
Otherwise, if it's below, then we need to set the exit attachment equal to seat dot exit attachment

558
00:36:45,780 --> 00:36:46,770
at the bottom.

559
00:36:46,770 --> 00:36:49,440
So attachment exit bottom.

560
00:36:50,430 --> 00:36:55,590
Once we do that, we can get the current occupant and we get the parent.

561
00:36:55,590 --> 00:37:00,810
Because remember, current occupant represents a humanoid and the parent of the humanoid is the player's

562
00:37:00,810 --> 00:37:01,640
character.

563
00:37:01,650 --> 00:37:07,380
And then we get the humanoid root part and the player's character, and we set the position equal to

564
00:37:07,380 --> 00:37:11,850
the exit attachment that world keyframe and get that position.

565
00:37:13,110 --> 00:37:17,150
And then once that's done, we just set current occupant to nil because there is no more occupant.

566
00:37:17,160 --> 00:37:17,910
They got out.

567
00:37:18,270 --> 00:37:22,230
We also need to reset the prompt to be enabled again because there's no one in the car anymore.

568
00:37:22,230 --> 00:37:24,810
So prompt dot enabled equals true.

569
00:37:25,470 --> 00:37:30,240
And then we need to stop the start sound and the idle sound in case they were playing.

570
00:37:30,240 --> 00:37:31,020
So start sound.

571
00:37:31,020 --> 00:37:33,240
We're going to stop an idle sound.

572
00:37:33,240 --> 00:37:36,390
We're going to stop just like that.

573
00:37:36,750 --> 00:37:38,600
And I think that's it for the car.

574
00:37:38,610 --> 00:37:46,170
So let's just go ahead and play test here just to make sure everything works as we expect and then we

575
00:37:46,170 --> 00:37:48,420
can go drive it around a little bit.

576
00:37:49,620 --> 00:37:52,290
So the car starts up idle sound.

577
00:37:52,290 --> 00:37:55,050
We can turn the tires in the correct direction.

578
00:37:55,050 --> 00:37:57,780
We can spin the tires forward backwards.

579
00:37:57,780 --> 00:38:02,190
And if we hop out, you see, we get teleported to that attachment above the car.

580
00:38:02,840 --> 00:38:07,820
However, let's say I decided to make the car upside down.

581
00:38:09,720 --> 00:38:11,250
And we'll playtest it again.

582
00:38:14,730 --> 00:38:20,620
Because this top attachments y position is going to be less than the one that is underneath the car.

583
00:38:20,640 --> 00:38:25,500
If I exit the car, we get teleported to the attachment below the car.

584
00:38:25,530 --> 00:38:26,400
Very cool.

585
00:38:27,580 --> 00:38:30,310
Let's rotate our car back to normality.

586
00:38:30,760 --> 00:38:32,860
We're going to anchor the body.

587
00:38:33,550 --> 00:38:38,080
And I've actually generated some terrain over here because we're going to test this bad boy out.

588
00:38:38,080 --> 00:38:39,910
So we're going to put our car right there.

589
00:38:39,910 --> 00:38:41,500
We're going to play right here.

590
00:38:42,960 --> 00:38:46,320
Now we're going to see if our car works as we expect.

591
00:38:47,610 --> 00:38:52,110
Of course, the physics are going to be a little weird because my processor is being taken up by the

592
00:38:52,110 --> 00:38:54,900
recording software and trying to calculate physics at the same time.

593
00:38:54,900 --> 00:39:00,960
So it might be a little wonky, but if we get in, our car starts up good and we should be able to start

594
00:39:00,960 --> 00:39:01,470
driving.

595
00:39:01,470 --> 00:39:05,460
But as you can see, we can rotate our tires and now we can drive.

596
00:39:07,000 --> 00:39:12,920
And as you can see, when our speed goes up, the idle sound gets its playback speed increased.

597
00:39:12,940 --> 00:39:13,390
Right.

598
00:39:14,580 --> 00:39:15,270
Just like that.

599
00:39:21,190 --> 00:39:25,150
And as you can see, our suspension is helping us out, making this ride a lot smoother.

600
00:39:25,150 --> 00:39:30,460
As you can see, our tires are moving up and down independently because of the spring we put in there.

601
00:39:30,460 --> 00:39:35,290
And those springs are also helped out by those cylindrical constraints that forces the tires to move

602
00:39:35,290 --> 00:39:40,570
only up and down a set amount so that the tires can only move up so much and they can only move down

603
00:39:40,570 --> 00:39:43,510
so much, just like it would be in an actual car.

604
00:39:45,760 --> 00:39:49,840
And since I have also increased the friction on the tires, we aren't sliding around that much at all.

605
00:39:52,220 --> 00:39:58,160
Now, if I were to go into the properties for these tires, these custom physical properties we set

606
00:39:58,160 --> 00:40:01,160
and let's say I reduce the friction to like 0.1.

607
00:40:01,770 --> 00:40:03,060
What do you think's going to happen?

608
00:40:03,150 --> 00:40:04,980
I say we're going to drift around all over the place.

609
00:40:04,980 --> 00:40:05,760
Let's find out.

610
00:40:06,730 --> 00:40:09,070
I don't think we're actually going to be able to grip the ground at all.

611
00:40:09,070 --> 00:40:09,430
Well.

612
00:40:10,070 --> 00:40:11,390
But if I drive around.

613
00:40:12,530 --> 00:40:12,710
Yeah.

614
00:40:12,740 --> 00:40:15,620
You can see we are drifting around.

615
00:40:16,130 --> 00:40:17,210
Watch more.

616
00:40:17,210 --> 00:40:18,800
Even though I stopped the car.

617
00:40:21,040 --> 00:40:23,460
You see, we are drifting around a lot more than before.

618
00:40:24,000 --> 00:40:28,830
But I'm going to, of course, reset that friction to be higher again.

619
00:40:28,830 --> 00:40:30,210
1.22.

620
00:40:30,210 --> 00:40:30,840
Maybe.

621
00:40:30,870 --> 00:40:32,310
Maybe we'll try out 1.5.

622
00:40:32,310 --> 00:40:33,540
Maybe that's a little better.

623
00:40:39,990 --> 00:40:42,060
As you can see, we don't drift around as much anymore.

624
00:40:42,240 --> 00:40:45,450
I mean, we pretty much stop, which is what a tire is supposed to do.

625
00:40:45,480 --> 00:40:46,380
It's made out of rubber.

626
00:40:46,410 --> 00:40:47,400
It would make sense.

627
00:40:52,710 --> 00:40:57,840
But otherwise, that's how you make a car with suspension or a simple car in Roblox.

628
00:40:58,200 --> 00:41:01,290
As you can see, it's actually not that complicated.

629
00:41:01,290 --> 00:41:06,780
You just need to have a little bit of knowledge on a couple of constraints inside of the Roblox API.

630
00:41:06,810 --> 00:41:12,780
Of course, you need to understand a little bit about angular velocity and torque on cars, but other

631
00:41:12,780 --> 00:41:18,990
than that, it only took us 89 lines of code and we've got a working car here that can turn, go forwards,

632
00:41:19,020 --> 00:41:24,690
go backwards, and if it flips upside down like this, we can hop out of the car and make it out.

633
00:41:24,810 --> 00:41:27,960
So I hope you enjoyed this lecture and I'll see you in the next one.