just wanted to report potential NAN (flickering black pixel) rendering artifacts on the automotive material pack car paint when using multiple, overlapping point lights (moveable) with source length and radius set.
I was able to isolate it to the material’s normal channel (i.e. disconnecting the normal, the artifact went away), but identifying the root cause is beyond my material expertise
I was able to reproduce it by adding the Automotive Material pack added to a default photoStudio project with ray tracing enabled in the launcher version of UE4.25.3. Windows 10, Nvidia Quadro RTX5000 (vR450 U3(452.06)).
Not sure if this would help, as it’s been a long time since this question was asked.
But I ran into a similar issue as well. One of the normalMap files (T_MetalWear_Wear02_N.uasset) has a few texels with a normal value of the form (nx, ny,0). It’s pretty unrealistic for this material since nz is exactly zero, and one of my custom nodes were doing this operation on it:return normalize(normal * float3(intensity, intensity, 1));. This op leads to NaN normals if intensity=0. Changing it to return normalize(lerp(float3(0,0,1), normal, intensity));fixed the issue.
Since this particular fix might not be relevant for your case, I would suggest that you make sure that any function ran after sampling this normal does not lead to a NaN if the normal value has z=0.
