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‫Hello and welcome.

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‫In this lecture, we're going to be firing off the cannibals in the forward direction of the camera

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‫and the cannonball itself.

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‫So if I hit space, you can see that I can actually start to aim this ball at objects and try and hit

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‫objects in the distance, which is a lot more fun.

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‫Yes, I got that chair.

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‫It's a lot more fun than it was previously.

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‫Let's dive in and see how to do this.

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‫So we're going to be using something called a forward vector, but what is it?

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‫So I've just, on the sake of argument on this slide, puts in an X and y directions just like we would

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‫have in the viewport to keep things grounded in that reality.

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‫And we can imagine we've got our camera here, that is the player's camera that when we rotate the mouse,

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‫it's turning around and we spawning it.

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‫Now our projectile and the newly spawned projectile is getting the correct rotation from the camera.

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‫So you can see this as I've depicted it on the slide.

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‫Now, the forward vector would be essentially the rotated X direction.

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‫So it is basically a vector that points in the forward direction after you have rotated it.

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‫So you can see this projector has been rotated around and its forward direction is over here rather

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‫than being off back towards the back of the camera because of the rotation that we've given it from

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‫the Player Pawns Control rotation, now we can actually get a right vector as well, which is essentially

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‫the Y axis that's been rotated.

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‫But we're not going to be using that because all we're interested in is sending the projectile in that

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‫forward direction.

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‫And what's interesting about the vectors that come back from Get Forward vector and from get write vector

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‫is that they have a length of one.

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‫Less can be guaranteed.

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‫They're always going to have a length of one.

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‫And this is really useful because if we want to apply a certain amount of impulse in this direction,

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‫all we need to do is multiply this vector to give us the direction by the value that we want, such

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‫as 400, if that's the velocity you want to give it.

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‫So enough torque, how do we actually achieve this in blueprint?

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‫So what we need to do is query that newly spawned projectile.

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‫We've given it the correct rotation over here before we spawned it, and it's been spawned with the

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‫correct rotation.

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‫We could see that when we play the game.

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‫So we need to get its forward vector.

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‫So to do that we can either pull off of the actor reference itself.

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‫So the reference to the beep projectile which comes out of the spawn actor node, or we could do it

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‫from the static component.

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‫Either one would work just fine.

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‫I'm going to do it from the actor just to save on nodes and keep things a little bit tidier.

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‫So what we're going to do here is type in, get forward vector and we can see two options here.

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‫I'm going to be using the get active forward vector.

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‫Both would actually give you the same result and then we've got ourselves the vector value.

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‫Now if we plug this directly into the impulse, we aren't going to see much of an effect.

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‫If we go ahead and hit play and we spawn a projectile, you can see it just drops straight down.

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‫And the reason for that is that the length of this vector is going to be one which, as we know, because

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‫of unreal units, that's in centimeters.

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‫So it's giving us one centimeter per second, which is a pretty puny velocity.

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‫So what we need to be able to do is multiply this vector by a float.

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‫Fortunately, we can do that fairly straightforwardly in blueprint.

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‫We can drag off of the return value for this forward vector and we can type multiply and that gives

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‫us this multiply operator node and you see by default what it wants to do is it wants to multiply a

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‫vector by a vector, but that's not what we want to achieve.

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‫And fortunately we can change that by right clicking on the second input node.

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‫We can click convert pin and we can convert the pin to a float and that gives us the correct type of

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‫multiplication that we want.

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‫So I'd like to challenge you to do this multiply vector for yourself.

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‫So plug in the multiplication node to both the input and the output to the impulse.

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‫And how much do you need to multiply by to get a force that you are happy with?

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‫Pause the video and have a go.

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‫Hello and welcome back.

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‫So we're going to I've already been using a value of about I think we said about 400 and then I'm going

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‫to plug in the output from the multiplication into the input for the impulse.

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‫So what we're getting is a vector that is 400 units long and is pointing in the direction, the forward

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‫direction of our BP projectile, the way it's rotating.

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‫And that is also at the same direction as our camera.

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‫So let's go ahead and hit play.

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‫And when we fire, you can see that it is firing off in the right direction, but with not quite enough

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‫force.

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‫So I'm going to increase this by make it 1000.

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‫Let's try with 1000.

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‫Okay.

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‫We're getting something a lot better now that we can actually start to enjoy.

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‫I think we had actually 4000.

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‫I think I'm just misremembering, if we go ahead and play now with 4000, you can see a projectile that's

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‫a lot more fun to fire.

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‫And the final thing that I want to do is because we don't need to know it's rotation anymore.

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‫And it kind of looks weird that it's this elongated shape.

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‫I want to go back into the beep.

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‫Projectile editor selecting the static measure component, go into the details pane and I'm just going

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‫to set the scale back to 0.5 like all of the other elements there, which gives us the ball back to

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‫being spherical.

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‫And if we go ahead and hit play now, we've got a nice little cannonball, which is actually a lot of

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‫fun to fire an objects and cause a little bit of destruction.

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‫Great stuff.

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‫We've achieved a lot in this lecture by applying that get forward vector node.

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‫I'll see you in the next one.