Large gaps in Lumen Scene

[antoninehomes]

When I run my UE5 windows build on a remote A5000 pixel streamed instance, I’m seeing huge gaps in the lumen scene (using debug console command “r.Lumen.Visualize 1” to see final lighting)

For reference, this is how it looks when it runs fine on my local machine:

In addition, when I visualize the Lumen scene’s indirect lighting (using console command “r.Lumen.Visualize 12”), the gaps in the Lumen scene appears to be filled with tiles of discrete color blocks.

Whereas the healthy looking indirect lighting on local machine looks like this:

The remote machine is using RTX A5000 GPU with 24GB VRAM, which at least on paper seems comparable if not more powerful than my laptop’s RTX 3070. Any ideas on how I might be able to debug this? Thanks!

[jblackwell]

While I have currently no idea what could be causing this, the errors look like products of the lumen surface cache probes being corrupted somehow- visualize the radiosity probes and see what they look like to help diagnose.

That said, an A5000 supports HWRT, doesn’t it? I’d enable HWRT at least to test the scene, to see if the SDF system is somehow causing issues as well.

[antoninehomes]

Thanks for the reply. Just to close the loop here for anyone encountering similar problems, it seemed that this problem was caused by our cloud provider upgrading their runtime from DirectX 11 to DirectX 12. Reverting the runtime back to DX11 solved the issue for us. (This is still a bit weird though since our cooked package had DX12 enabled and it works fine with DX12 on my local machine… but alas, that’ll be an problem for another day…)