How can I stop my meshes from flickering/popping in when turning a corner?

Hello everyone!

I’m having problems with some of my geometry seeming to flicker when I turn a corner and the skybox appearing through them (even though there is other geometry behind it in the forms of other corridors and hallways). All the geometry intersects with one another and there is no light leaking so I do not know what the problem is. All the meshes are two sided and the material is two sided as well (not efficient but hasn’t stopped the problem). If anyone can help that would be very much appreciated!

Problem is illustrated here:

I have tried a few things to fix the problem however they have not worked:

  • Placing a hollow bsp volume around the level to block off the skybox and directional light (however the skybox still flickers through
  • Toggling on and off double sided geometry and double sided material
  • Placing in a precomputed visibility volume encasing the whole level (it’s a very small level however still hasn’t worked)

Additional info: All meshes are instanced and are all modular pieces that fit together with a tiny bit of overlap. However the problem still happens to big pieces of geometry which aren’t overlapping.

The problem also seems to be aggravated by speed and looks much worse at higher look rotation speeds, even though we’re using a slower look rotation speed the problem still persists.

Thank you very much for your time!

Hi Dfairburn,

This is caused by occlusion culling to help optimize the level by not rendering what is not visible within their bounds.

I’ve covered this in this post here: How does object occlusion and culling work in UE4? - Rendering - Epic Developer Community Forums

I’ve also got a quick video that covers occlusion culling, different tricks, and pointers here: PBF: Brief Overview of Occlusion Culling - YouTube

Hope this helps!


1 Like

Hi Tim,

Thank you very much for your response! This solution has worked perfectly!

Again thanks for your time and help,