Hello. I found an issue with Lumen SWRT. I Launched ThirdPerson project with 5.5.2 and have almost all lumen mesh cards missing with lumen SWRT enabled. I debugged some shaders and found that adding the next code inside the SortObjectGridCell() (GlobalDistanceFieldObjectGrid.ush) fixes the issue. Can you please help me to figure out what is going on wrong?
+if (ObjectGridCell.PackedIndex4[ElementIndex + 1] != 0xFFFFFFFF) +{ ObjectGridCell.PackedIndex4[ElementIndex] = MinIndex; +}
Steps to Reproduce
Open third person project with 5.5.2, disable lumen HWRT (r.Lumen.HardwareRayTracing 0)
Hello,
Thank you for reaching out.
Keep in mind that Unreal Engine 5.5.2 has a known critical issue, which is fixed in Unreal Engine 5.5.3
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Can you please send us a minimal test project that demonstrates Lumen SWRT culling nearly every surface?
The guide for test projects: [Content removed]
Hello. Here is the project. But actually i have this issue on any project
Hello,
We were unable to reproduce this issue, using Unreal Engine version 5.5.2 (CL: 39378466) and your test project.
[Image Removed]Can you please make sure your graphics drivers are up to date?
If the latest graphics drivers do not solve the issue, can you please share what graphics card and driver version you are using?
Can you please share the logs from the test project where you do not see the Lumen Scene properly populated?
Hello. I’m using latest driver for RTX5080. The log file is attached
Hello,
What is the value of “r.DistanceFields.SupportEvenIfHardwareRayTracingSupported”? If it is 0, can you try changing it to 1? Please note that you cannot change this CVar at runtime - you can change it with the command-line argument“-dpcvars=”r.DistanceFields.SupportEvenIfHardwareRayTracingSupported=1”.
From your logs, we can see you are turning Lumen hardware ray tracing off during the session. Can you please try turning it off at startup with the command-line argument “-dpcvars=”r.Lumen.Reflections.HardwareRayTracing=0,r.Lumen.HardwareRayTracing=0”?
As a test, can you also check if there is a difference between “r.Lumen.TraceMeshSDFs” 0 and 1, with regards to the culled surface cache?
As a test, can you also try setting “r.RayTracing” to false to see if the issue reproduces in that scenario?