When we run our game on Vulkan (SF_VULKAN_SM5, client, no editor), we sporadically get the big blocks of blackness, which tend to grow and consume the whole screen. I’ve traced the source of this corruption to the compute shader calculating Light Scattering 3D texture for Volumetric fog. See the attached screenshot of RenderDoc frame capture, API call 4334 vkCmdDispatch(60,34,32). As you can see in the screenshot, starting from slice 50 of this texture we have a block of INF (infinite) colors. After the fog is applied, these colors in Light Scattering texture result in NAN (not a number) colors in the frame buffer, which are then displayed as the black areas in the final frame.
We use the Unreal 4.21.2, NVIDIA GTX 1060, driver 24.21.13.9882.
Perhaps this is related to “UE-64142 Volumetric Fog causing Black Artifacting on Particle and Rect Lights”, which is claimed to be fixed in 4.21 preview 3?
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