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In this lecture, we're going to be making our play a drop from the sky and run left and run right when

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we push on the keys on the keyboard.

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So let's get started.

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First question I have for you here is what do we need to access on our player to make the player move

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around?

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What's the core movement thing that physics applies to or allows us to push the player around?

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It is the rigid body.

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So well done if you guess that or yelled it at your computer out loud.

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So we need to access the rigid body.

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Let's start in our script by caching a reference to rigid body.

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So if you know how to do that, pause a video and do that now.

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And if you're thinking, What's Rick talking about?

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Let's do that together.

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So I need to create a variable which would be a type rigid body 2D.

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Don't forget the 2D.

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I often forget that also there's not a capitalization on the B, which I mess up as well at times,

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and we'll name this rigid body actually rename this my rigid body so that it doesn't complain.

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Sometimes it doesn't like when you just do rigid body because it thinks you're referring to something

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else.

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So my rigid body and semicolon now within start, what do we need to do?

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We need to my rigid body equals get component.

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What sort of component is it?

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It's a rigid body to dx parentheses semicolon.

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Okay, now we've got to read your body.

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What do we need to do?

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Well, we need to create a run method.

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We need to say, move this way, move that way, run based upon what the player input is.

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So first of all, in update, I'm going to call the method run.

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I haven't created this yet, but I'll say run.

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What does run mean?

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Well, let's jump down right below on move.

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We will create ourselves a new method void run parentheses, curly braces.

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So let's start with a really simple implementation and then we'll make it a little bit cleverer.

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So within here, what we're trying to do is say my rigid body velocity.

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That's how we're going to be moving around our character equals what?

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Well, we can just say for now equals our move input.

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That's our vector to move input per semicolon, save that up and then jump back into unity.

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Click on play.

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What happens in here?

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Well, we can go left, right, up and down.

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Excellent.

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But it's kind of weird.

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The play is floating, which we don't want, and the play is moving kind of slow, which we don't want.

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And the play is actually being out of fly up and down.

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We only want the player to be able to move up and down when they're on a ladder.

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Let's tidy up our run method in here to be a little bit more sophisticated.

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So rather than just straight up move input, let's create ourselves a new variable which would be of

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type vector to and we'll call this player velocity and that equals and we know we can't just say that

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equals one and three because unity will say, I don't know what you're talking about here, one and

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three.

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What does that mean?

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So we need to say, well, I'm going to give you two values and it will be in a vector two.

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So new vector two, we cast it to a vector two and then player velocity knows what it is that it's supposed

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to be receiving, what these numbers are that it's getting and putting into its vector two values.

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So what I'm going to do on the x axis is move input.

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That's currently a vector to remember.

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I only want this to be on the x, so let's move input x to say just give me the x value and then comma.

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I mean we could put move input y, we would get exactly the same behavior as we just had.

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So we don't want that.

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We want something different in here.

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We don't want the player to be able to push up and down unless they're on a ladder.

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And that will be in a different method, which we'll call climb ladder.

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We don't want that in run.

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So for now, I'm just going to put zero and see what happens.

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Oh, and then the last step here is we need to make sure instead of move input, we need to have player

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velocity as the values that our rigid body velocity is receiving.

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So player velocity, save that up, back over into unity.

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Click play.

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Now we can't move up and down.

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That's great.

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Perfect.

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But I can move left and I can move right now.

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We've got some weird behavior.

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The players are slowly floating down because we're saying zero, don't give it any velocity.

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It's trying to resist gravity, which is not what we want.

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So let's go back to our code.

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I've got a challenge for you in here, and one is a simple challenge and one is a tricky challenge if

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you're ready for it.

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So the simple challenge here is add something to our script to give us control over how fast the player

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runs.

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Because you can see it's not a very compelling platform if you're only moving that quickly.

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So that's the simple one.

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And then the tricky one is trying to figure out how to make the character behave normally on the Y axis.

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In other words, to respond to gravity, to not be able to fly up and down the air.

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We've already removed that and to not get stuck.

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So not just to be sort of stuck there floating in the middle of nowhere.

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So see if you can have it.

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So if you can figure out to say just behave normally, it's a tricky one, this one.

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So if you don't get it, no worries.

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But give it a shot.

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Have a think about it, see if you can wrestle with it and find the solution.

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So pause the video.

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Take that on C back here when you are done.

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First step, I'm going to add a new serialized field right up the very top serialize field, and this

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will be of Type Float and I'll call this run speed and I'll initialize that at say ten, ten F because

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it's a float and that's going to be our variable that we will then jump back down here and run and say,

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move input X multiplied by run speed so that we can speed up how fast we're moving.

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If we're receiving a minus one to plus one, we can then multiply it by ten.

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So it'll be from minus ten to plus ten that we're adding to the player velocity or pushing the player

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each frame.

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Now what are we going to do about this pesky y value in our vector two?

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What I'm going to do here is access the my rigid body velocity dot y and say that's it.

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And what my logic here is, is saying that whatever your current velocity is on y, just keep that,

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just do the same because we're adding a new velocity each frame.

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We only need to be adding the x, we don't want to be touching the Y.

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So instead of saying it's zero, we say just keep it as it currently is.

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So let's see before I celebrate too much, I'll save that and see if that worked.

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Click on a play.

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But drops to the ground and left, right.

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And we're running really fast, probably a little bit too fast, but we can tune that later on.

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We can't move up.

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We can't move down.

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But the player is responding to gravity.

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There we go, falling off the screen.

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So there we go.

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We've implemented left and right movement for our player using this code, using our run method so that

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we can move left and right with our player.

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I'll see in the next lecture.