I have encountered an issue with translucent shadow casting in Unreal Engine 5.7.When ray-traced shadows are enabled, the directional light Source Angle causes shadows to blur and disappear depending on camera distance.The issue is resolved when I set the Source Angle to 0.However, I still need soft blurred shadows.I would like to know the solution, and which console commands can fix this problem.
Would you be able to record video of the transition?
If I understand correctly, the problem is that the penumbra of the shadow is changing as the camera moves instead of staying consistent. Is that true?
This is a use case with so many different potential problems that it’s genuinely hard to name them all. The first thing is just making 100% certain that you’re using pure, normal RT shadows, not VSM, not megalights. Then, take a look at the acceleration structure, see if your object is dissapearing prematurely in the ray tracing view, which would explain the dissapearing shadows. Third, validate the scene via the path-tracer to see if there’s a difference in the RT shadow implementation that might explain some things.
Well, thank you for your reply. I will use the official sample level to give you a demonstration. Currently, I have only enabled ray-traced shadows for the sun light, and entered two command lines: r.RayTracing.Shadows.Translucency 1 and r.RayTracing.Culling 0. You can watch the process of its disappearance.
Of course, this happens with the default Source Angle value of the sunlight. When the value is set to 0, the shadows work properly. I have also tested path tracing, and the shadow performance remains completely normal.
If the light source is a typical sun, the shadow is also too blurry when the sphere is that close to the ground. When the camera is also close.