Unreal Engine Issues

Spline mesh can not cast shadow when raytracing enabled.

Crash in editor when loading a procedural mesh that has multiple sections and raytracing is enabled

Validation error in FSkeletalMeshSceneProxy::GetDynamicRayTracingInstances due to wrong LODSection.SectionElements count

The following condition is sometimes not met: LODSection.SectionElements.Num() == MeshObject->GetRayTracingGeometry()->Initializer.Segments.Num() ...

Editor crashes when using decal material on Instanced Static Mesh with Raytracing

This issue can occur when setting the Decal Material to Instanced Static Mesh in a Raytracing enabled project. (If there is a cache, it will not crash.) The cause is that DefaultDeferredDecalMateria ...

Disabling Shadow Denoiser causes raytraced shadows from Rect Lights to disappear

Disabling Shadow Denoiser causes raytraced shadows from Rect Lights to disappear ...

Raytraced reflection doesn't work with high roughness

Even when the max roughness for raytraced reflections is set to 1, they seem to be blended away at far below that value. For projects (e.g. film,vfx) where quality trumps speed it would be valuable ...

Back-face culling not working when translucency is set to Ray Tracing

While enabling Ray Tracing from the start of the project, when user sets GlobalPostProcess Translucency to Ray Tracing, the back-face of the plane is not culled. However, when the translucency is se ...

Ray Tracing Translucency - Sample settings have no effect

Ray tracing translucency samples per pixel settings have no visible effect.  Reported and tested in version 4.25.3(CL 13942748). Tested and found in versions 4.25.3 and 4.26.0 Preview 2(CL 14419252 ...

Ray traced shadows appear even after the mesh is hidden

bCastHiddenShadow flag in UPrimitiveComponent doesn't affect ray tracing shadows ...

Crash enabling Stochastic Rect Light with Ray Tracing

Enabling Stochastic Rect Lights with Ray Tracing causes the project to crash. Reported and tested in version 4.26.0(CL 14419252). Tested and not found in version 4.25.3(CL 13942748).  ...