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ConsoleVariables.ini changes causes z-fighting

Hello, I have updated Engine\Config\ConsoleVariables.ini to have those settings:

[Startup]
r.ShaderDevelopmentMode=1
r.Shaders.Optimize=0
r.Shaders.KeepDebugInfo=1

so that I could debug shaders. I then noticed some z-fighting appearing. That is, removing above changes removes z-fighting. The problem is the behavior is not consistent. In one extreme case, previewing with Oculus Rift resulted in a glitch very similar to bad resource transition on console (weird black patterns showing up for only 1 frame). I was lucky to capture the problem in RenderDoc and notice z-fighting on the left eye. Vive, PC and editor were ok.

Can you comfirm this behavior? Is it possible to fix it?

Thanks.

Repro steps:

  • UE 4.18.2
  • Make changes to ConsoleVariables.ini
  • Create default project with minimal content (skybox and a floor).
  • Add TutorialTPP skeletal mesh (comes with engine content)
  • Make sure it has its Tutorial_Walk_Fwd animation (comes with engine content)
  • Preview in VR with Rift
  • Notice that, once in a while, black lines/dots/patterns are visible for 1 frame.

I came across the same issue in 4.20 and 4.22.