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Welcome back.

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As we finished in the last lecture, you can see that currently, Barry, when we click on play just

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kind of stops there.

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He's not like the ball that was able to roll down this hill using physics.

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He's just kind of stuck there and that's fine.

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We could solve this by going down the path of adding physics, like adding force that pushes the player

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along, that pushes the player a different amount up hills and downhills.

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We can play around with gravity.

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There's play around the friction on the snowboard.

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There's a lot we can do there, or I can show you a really cool feature in Unity and we'll use that

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cool feature to make our snowboarder move.

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And that cool feature is using an effector and the sort of effector we're going to use is the surface

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effect, the 2D.

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If you jump over to the Unity documentation, I've given you a link against this lecture for that.

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In the resources section you can see that the surface effector to DH applies tangent forces along the

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surface of colliders.

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What does that mean?

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Well, this is analogous to a conveyer belt, so we're trying to make a conveyor belt by adding some

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sort of force that we apply along our collider.

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So we've got our collider that's going along the edge of our of our world here.

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We want to apply a conveyor belt effect to something that pushes anything, that collides with it in

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a particular direction.

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So it's going to conveyor belt it along.

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There's other types of effectors.

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Let me just jump back to effect as to do that.

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You can play around with their surface effector point effector platform effector buoyancy and area effector.

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So there's a few of these that you can play around with.

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But for now we're just focusing on this conveyor belt or service effector to DX and it's going to be

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easy peasy to implement this.

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So what we need to do is click on our level, sprite shape, jump down, find our add component search

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for effector.

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We're looking for the surface effect, the 2D click, there we go, scroll down.

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We can have a look at the details on that and let's click on play and see if anything happens at this

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point.

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Okay, nothing's happening.

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Of course, that means we need to do a little bit of sleuthing in here.

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And if you have a look at our Edge collider, you can see there's a setting in here which says Used

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by effectors.

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In other words, it's saying if you drop an effector on here, it's not necessarily going to know which

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edge collider you want to be using because you might have a few edge colliders, but if we say used

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by effector now the effector will know, aha, this is the edge.

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Collider When something touches this, I'm wanting to push along that edge.

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Collider So now when we click on play, we'll see what happens.

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Okay.

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He's moving.

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Wasn't moving before.

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Moving very, very slowly.

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So let's have a look at our settings in here.

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We've got our four speed, we've got our speed variation, we've got our force scale.

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Let's try adding 20 into speed and see what happens in here.

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So when we click on play now with 20 and our speed for service effector, you see problem Barry's getting

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pushed along.

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However, he's getting stuck at this point here and that's something that we had our initial success.

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Let me just move him up the hill a little bit here.

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Make sure you clicked on the parent whenever you do any of these things, because if you click on just

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the top, then woop you just move the top, but not the entire game object.

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Not Barry in his entirety.

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So popping up here, I'm going to click back on my level shape and I'm going to move this down the speed.

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I'm going to change that back down to ten just so he's not moving quite so rapidly and flying off the

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thingy.

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So you can see here he's touching got speed, speed, speed, speed, speed.

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You can see the camera is flowing over here, doesn't really rotate very well goes up there up does

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a little bit of a jump all good making progress bump and then it gets stuck and falls through the world.

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Now the effect is working, but we've got an issue with our collision that's easily solved.

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If we click on Barry, we find Barry's rigid body.

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You can see collision detection is discrete.

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We want that collision detection to be continuous.

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So that's going to require more processing power because Barry's the star of the show, we don't mind.

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It's going to do a more continuous collision detection.

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So if I'm right with this, he will fly down the hill, do his kind of weirdness, but he's not going

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to get stuck because we're doing a much better collision detection.

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And on this hill, our effector or our conveyor belt is still going to keep pushing him along as we're

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expecting it to do.

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So that's mission accomplished.

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The effector is that easy to move things along if we want to twiddle with it a little bit, you can

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see while we're clicked on our level, sprite shapes don't play mode.

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If we get there and change the speed to say, I don't know, minus ten, then it's going to make Barry

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go backwards because it's pushing in the other direction.

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The conveyor belt is going backwards.

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We put it back up this way, but do it to a smaller amount.

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Then he's moving along.

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If you increase the force scale, that's a way of saying don't respond to any of these gravity things

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like up the hill.

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It's going to go up the hill exactly the same no matter how steep the hill is.

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But if I push this all the way down to say 0.001 on the force scale, he's kind of stuck on the hill,

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doesn't have enough force to push him up.

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And if I increase that, then it does.

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If I put it down to zero, not enough.

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So a little bit more force, a little bit less.

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So you can see there's a relationship.

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Speed is how fast he's going to move or how fast the conveyor belt is moving and the force is how much

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we're applying that force to counteract any gravity that we might have with our game object.

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Where's that gravity coming from?

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Well, it's currently on Barry.

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If you click on Barry, you can see that he has a gravity scale of one, which is fine.

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We can play around with that at some point, but it's cool for now.

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So little sprite shape, I'm going to put this back to actually if we get out of play mode because I

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was in play mode while I was doing that, it'll reset our values back to what they were when we first

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clicked on play mode.

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So there we go.

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I love Effectors and I love this surface effector.

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It's so powerful.

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Just by dropping that in instantly, we've got this character moving along, looking like he's a snowboarder.

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And one cool thing, if you haven't noticed it already, if you were to increase speed up and decrease

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speed, notice how it only affects him when he's in the air.

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So if I go woop really fast and then put it all the way down really low, is he going to land on the

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world loop?

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And he's going backwards now?

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So I put it all the way to backwards, but it's only if you're touching the effector that that has an

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impact when you're in the air.

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It doesn't.

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Also it's good to know is that we can modify this value here in our code.

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So if the player pushes a key on the keyboard, we can have them speed up if we wanted to, to give

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them a boost.

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So that's really cool.

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Whenever you see these values on the components, just have a think about the fact that, you know,

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we can modify these in our code to do cool things such as with the speed.

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So there we go.

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There's an introduction to effectors, specifically the service effector.

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Now we have our snowboard out moving along our world.

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I'll see you in the next lecture.