How to draw debug arrow on top?

Development Platform & Builds Debugging, Optimization, & Profiling
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1

I would like to draw some vectors using DrawDebugArrow in Blueprints. The problem is I can’t always see them, when the vectors are inside of an object. Is there any solution to draw them on top of everything on screen?

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276967-ue4.png925×521 457 KB

As you can see in the picture, red arrow is almost inside and hard to see

2

You can use Custom Depth with a Post Process Material: Post Process Materials | Unreal Engine Documentation

3

I have already added comment to your answer, but it seems like it is deleted. lol. Anyway I don’t know how I can apply a Post Process Material to debug arrow. Documentation says it works with meshes and arrow is not a mesh I think.

4

I haven’t found any solution, so I decided to see the implementation of debug arrow, and it turned out the functionality I need is already there.

277454-beztytułu.png
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All I had to do was to change one argument in function. By default the value was SDPG_World and changing it to SDPG_Foreground make the arrow render always on top exactly like I wanted.
I don’t understand why this argument is not exposed for blueprints by default.

Here is the result

277455-beztytułu.png
277455-beztytułu.png763×470 335 KB

1 Like
5

Sorry, I might have missed that only DrawDebugArrow works for you. I don’t think it’s possible to do what you want with DrawDebug commands, as you can’t control the mesh nor the material that is drawn, and you need to have a separate depth pass for meshes that you’d like to draw on top.

6

I found a solution, but I had to make changes to the function in C++. I added the solution in an answer.

7

Yes, it took me a lot of time with my third world computer to compile it and almost 80GB of space (source, project files for visual studio, binaries, etc) but it worked XD

8

Nice find, although I guess then you have a source build of the engine, right?

9

You could have just made a blueprint function library in c++ and made your own function.
Kinda like this:

#include "DrawDebugHelpers.h"

void MyBPLibrary::DrawDebugArrowForeground(const UObject* WorldContextObject, FVector const LineStart, FVector const LineEnd, float ArrowSize, FLinearColor Color, float LifeTime, float Thickness)
{
#if ENABLE_DRAW_DEBUG
	UWorld* World = GEngine->GetWorldFromContextObject(WorldContextObject, EGetWorldErrorMode::LogAndReturnNull);
	if (World != nullptr)
	{
		DrawDebugDirectionalArrow(World, LineStart, LineEnd, ArrowSize, Color.ToFColor(true), false, LifeTime, SDPG_Foreground, Thickness);
	}
#endif
}

No engine build required

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