DBuffer Decals flicker when moving

Currently enabling DBuffer decals in 4.10.4 causes decals to flicker when the camera moves.
Heres a gif of the problem

Hi Shirk,

I’m not able to reproduce this using a basic dbuffer decal and scene setup. I’ve attached a sample project here. Can you reproduce this in that project and reupload it here for me?

I also tested this scene with 4.10, 4.11, and our internal build of 4.12 with no issue.

If you’re able to reproduce, also make sure to include all repro steps.

Thank you!



I downloaded the project, and initially the decal works as expected aside from the decal shifting around while you’re moving, but I assume that’s just an issue with deferred decals themselves. But I found the issue to be if you have a very small vertical height for the decal. In your project you have the decal 128 units tall, which although works, is extremely impracticable as a decal because of stretching along vertical surfaces. I set the decal to be 5 units tall to prevent that issue because you wouldn’t want an object to move over the decal and then suddenly have the decal applied to it, in almost no scenarios is that wanted.

The issue remains if you change the decal height to a very low number.

It looks like zfighting, but the decal has volume so it shouldnt be happening.

I’ve submitted UE-28917 for this to be tracked. Once there is an update I will post back here with any relevant information.

Thank you!

I know this comment could be less valuable than 2 cents but I had the very same problem as Shirk but I solved because in Project Setting → Rendering → Early Z-pass I had forgotten “Decide automatically” instead of “Opaque and Masked meshes” and in my case the decal is scaled x:2 y:13.5 z:13.5 (so really tiny)

I tried your suggestion, an although now the flickering is gone, the decals can appear through other objects.


I dunno if laugh more for the decals through the objects or for the trump target dummy! :'D

-serius mode on- it’s strange because my decals haven’t that problem: may the decal volume too big (in this case too high)? I know it’s another 2cents suggestion…

I’m getting this but also a big translucent sphere on the left that rotates as I move around. I changed the primitive in the decal’s material editor to a plane and noticed it changed in the viewport too!

A very strange bug.