Lumberyard 1.13 New Culling Bug

We recently updated to Lumberyard 1.13 and are now experiencing a culling bug. When you move or rotate the camera, meshes in the scene will flicker in strange ways. It usually happens to meshes in the distance but it can also happen to ones that are closer to the camera. A good repro case is to simply rotate the camera up and down (pitch up and down) while looking across our landscape (which is made of static meshes). As you do this, you can seen chunks of landscape flicker on and off. When a mesh is incorrectly culled, it never stays that way. If you stop moving the camera, the culling will always settle in a state where everything is drawn correctly so the bug is intermittent but very frequent and distracting.

Lumberyard 1.12 does not have this problem for us. I looked at the changes between 1.12 to 1.13 and I see that the multithreaded job code has been worked on. I’d bet there is a new race condition or something of that sort.

I have a video of the bug but the forum won’t let me attach an mp4 video file (6.6mb)