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‫Hello and welcome.

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‫In this lecture we are going to be spawning our rifle at runtime from our character class in C++.

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‫Let's dive in and see how it's done.

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‫Okay.

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‫So we want to get our gun spawning as a child of the shooter character, the first point of call is

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‫to be able to spawn that actor from within another actor.

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‫We're going to do this at runtime.

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‫We're going to do it at begin play because that's the way you kind of need to do it.

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‫When you're spawning actors, you need to do it at runtime.

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‫And the way we're going to do this is we're going to get hold of the world first.

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‫So get a world and then we're going to call a function on get world, by the way, world and level a

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‫synonym.

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‫So what we're actually doing here is we're going up to the level and saying, hey, level, can you

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‫create as an actor because all actors essentially belong or live in a level?

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‫So then we're saying, you know, spawn actor for me, please.

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‫And this is a spawn actor that takes a template.

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‫You can say, I want this actor that I'm going to spawn to be of type A gun.

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‫And for that to work, we're going to need to have an include up here hash include for the gun dot h.

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‫And then we're going to take in an argument and the argument to spawn is actually can be a class type.

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‫So by default it will go ahead and spawn the C++.

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‫But here we want to spawn the blueprint child of this gun.

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‫So we need to figure out what that's going to be that needs to be hooked up in Blueprint.

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‫It can't be hooked up here in C++, at least not easily.

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‫The best place to do it is in Blueprint.

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‫So we're going to do an alt oh to go to the header file for our issue to character.

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‫And we're going to add in a new you property here.

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‫To allow us to configure the class that we should be pointing to in order to spawn an actor.

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‫Which blueprint class should we be spawning from this shooter character?

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‫We're going to have it as an edit defaults only y edit defaults only because we don't want to be able

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‫to edit this at runtime because it would give a false impression that you can change what type of gun

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‫we're using at runtime.

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‫Whereas Begin Play has already been called that guns already been spawned and so it wouldn't actually

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‫update anything.

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‫So we don't want to make it editable to give not give people a false impression of what can be done.

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‫And then here we're going to use a macro called T subclass of which you may or may not have come across

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‫before and DT subclass of is a template.

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‫So we use these angle brackets again and we want it to say a subclass of gun.

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‫And basically what this means is that it allows Blueprint to restrict the classes that we can select

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‫from to only the classes that are subclasses of the Gun C++ class.

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‫Now this isn't going to be a pointer because we're not pointing to an actual instance of the gun.

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‫What we're getting here in this variable is a class itself.

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‫In this case, it's a blueprint class, but it's still a class.

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‫So what we're going to want to call this is the gun class, just to make it super clear that this is

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‫not actually the gun itself.

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‫We do want another property here to store the gun, and that is going to be not an edit default.

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‫So basically, we don't want to make this a visible property at all, but it's going to be an A gun

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‫pointer.

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‫See the difference?

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‫One of them is a subclass of gun, the other one is a gun pointer and this one is the actual gun.

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‫That's once we've created an instance of the class, that's where we're going to store it.

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‫So let's go on over in to our shooter CP and finish off this begin play where we are spawning things

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‫so we're going to have gun equal to get world spawn actor gun.

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‫And the argument we're going to pass in here is the gun class, which we're going to be setting over

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‫in Blueprint.

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‫So let's go and try and compile this.

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‫It may give us some errors.

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‫Let's see, I have the message log open with the compile log and sure enough, we're getting some errors

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‫over here in the head file saying undeclared identifier because we need to forward declare the gun.

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‫So I'm just going to do this at the top because it's in two places I'm going to say class.

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‫A gun like so.

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‫And just a reminder, forward declaring like this means that we can keep our compile times down by not

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‫including too much in the heavy header files.

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‫Let's try recompile and see.

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‫Looks like that was the only error.

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‫It's now compiled successfully.

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‫Let's go ahead and hit play and see what happens.

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‫Exit.

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‫Have a look at our.

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‫We basically want to have a look at the message log, which I don't have open.

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‫So let's go to window and developer tools and have a look at the output log and see if we have any errors

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‫here.

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‫Yes, spawn actor failed because no class was specified.

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‫Sure, no class was specified because we didn't configure it yet in blueprint.

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‫So this I'm going to give as a challenge to you to hook up the gun, find the property in our character

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‫blueprint, set it to the correct gun and test that it spawns.

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‫Pause a video and have a go.

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‫K Welcome back.

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‫So let's go over to our shooter character BP and find the property which should be on the route or the

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‫class.

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‫Defaults go into details and undershoot a character.

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‫You can see we've got a rotation rate here which we have configured and we have got our gun class,

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‫which is a dropdown which allows me to choose between the gun being the C++ gun.

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‫And here's where our naming convention comes in handy.

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‫The things prefixed with BP underscore are the blueprints.

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‫So we want our BP underscore rifle, go ahead and select that compile save, go over in to the scene

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‫and hit play.

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‫Now, hopefully, we have not got any errors about about spawning our gun.

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‫The gun should have spawned.

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‫Okay.

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‫And to find out if it has, we can f eight and have a look in the world outline.

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‫If I make the world outline a little bit bigger, I can search for the BP underscore rifle.

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‫Hurray.

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‫We've got a BP underscore rifle the moment it's in the middle of nowhere and it's not correctly child

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‫ID.

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‫That's going to be the subject of the next lecture.

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‫So I will see you there.