I am using UE5.1 and UE5.2, and in both when I import an FBX from either Daz or Blender I get fine textures under lumen without raytracing hardware support. As soon as I turn it on and rebuild shaders, I get this ugly black patches on my mesh. I have tried it with different meshes, and it is the same. I tried changing the default anti alias settings, but nada. This is a big blow to my workflow since I have so many daz props, and dazto unreal stopped working a few weeks ago out of the blue for no reason…just fails everytime. I also tried using glb format, and it is the same. Any ideas?
this is a total guess but perhaps something funny about the edge smoothing?
can you put model in a 3d program and soften/harden the edges and see if that makes a difference?
as a test you can get some other models from somewhere else and see if the problem exist on them as well.
I tried it with a model from production crate , Blender, and Daz3d…they all were the same. It works with lumen only lighting, but not with hardware raytracing. Thank for your response, by the way. I don’t know how to smooth the mesh–would that be like applying a smooth modifier in blender?
sorry i don’t know about blender. smooth modifier there could mean like subdividing and smoothing the mesh (that’s what it would mean in maya).
What I am talking about it how the normals of the edges is calculated, however I had misread your post. I thought you had said that it works with normal lighting but not lumen.
It sounds like its something specific to ray tracing but I have no clue about that.
It has to do with hardware raytraced shadows and lumen.
If you disable Ray Traced Shadows it should be fine.
Project Settings → Rendering → Hardware Ray Tracing → Ray Traced Shadows
The issue is due to the mesh triangulation . When you import a mesh inside Substance 3D Painter, it automatically triangulates the mesh in the backroom. Therefore, some visual issues may happen when you apply your new textures on the non triangulate object.
Actually, when I imported the mesh as a skeletal mesh it worked fine. No problems after that.