Change the pivot of an actor and make it custom size programmatically

[ViaCognita]

Hi!

I’m using Unreal 5.2.1 and I’m trying to draw a line between two actors. I’m not using DrawDebugLine. Instead, first I created a Niaga System Effect but it looks ugly:

So, I decided to do it using a Procedural Mesh. I get the idea from this post 3D Lined Polygon using Procedural Mesh in Unreal Engine with C++ – 3D Developers' Survival Kits.

I have created an Actor component for the procedural mesh, and an actor with this component:

UCLASS()
class MYPROJECT_API APStickActor : public AActor
{
GENERATED_BODY()

public:
// Sets default values for this actor’s properties
APStickActor();

protected:
// Called when the game starts or when spawned
virtual void BeginPlay() override;

public:
// Called every frame
virtual void Tick(float DeltaTime) override;

UPROPERTY(EditAnywhere)
class UPStickProceduralMeshComponent* LineComponent{ nullptr };

};

The Procedural component is just a 2D polygon representing a line:

I’m not sure, but I think the component doesn’t start drawing at (0, 0, 0) inside the actor. Instead, the middle point of the component is (0, 0, 0). In other words, if I place this actor in a level at (0, 0, 0), I will have the half side of the line before (0, 0, 0) and the other half side after (0, 0, 0).

How can I make that component start drawing at (0, 0, 0)?

Thanks!

[eldany.uy]

you can acttually place your poly at the midpoint of the desired targets, then orient the poly with lookAt (from point a to B) and finally scale its X using distance from A to B.

midpoint = (pos1 + pos2)/2
distance = vector lenght of pos1-pos2

[ViaCognita]

@eldany.uy Thank you for your answer.

I’ve tried it, but the procedural mesh is on Y axis and I don’t know why.

Is there a way to create the mesh on X axis or rotate the component inside the actor to X axis?

Thanks.

[eldany.uy]

and you can’t scale Y instead?

also…why you want to use a procedural mesh for drawing a line? why not just use a standard static mesh for that?

[ViaCognita]

@eldany.uy

why you want to use a procedural mesh for drawing a line? why not just use a standard static mesh for that?

Because I’m a newbie and I’m guessing what to use.

[eldany.uy]

Well no so newbie as you using C++

Let me try to make a prototype of that with BP and share with you with some video.
If I have time I can move to C++ too.

[eldany.uy]

if you hold the mouse button in the YT video you can actually wath it x2 speed

[ViaCognita]

Don’t worry. The problem is that I searched about how to draw a line and someone said that we can’t do that in Unreal, only debug lines. As I have no idea, I didn’t think in other possibilities.