UE 4.27 - Raytracing, shadow issues with RT shadows off

Development Rendering
, , , ,
1

Hi,

I’m trying to utilise RTXGI and raytraced AO for my project. Everything functions as expected including the issues with WPO foliage shadows. However I’m seeing some strange render issues with raytraced AO (I think)

With Raytracing on and raytraced shadows from my direct light source I have shadow issues using wpo foliage. When I place a mesh directly and tick adjust for wpo the issue goes away, but only at a certain draw distance.

Even if I disable raytraced shadows on all light sources the issue remains the same. Only way to get rid of it is to cull the shadows completely or untick cast RT shadows in the material, leaving me with no shadows at all, including a lack of AO.

I feel there must be a setting / command I’m missing since it works at a certain draw distance as shown in the video.

Camera is located above the pawn
X - 3100
Z +4600

2

I let this rest for a while and found the solution at a later stage.

I will leave it here in case anyone else has the same issue in the future.

The problem is related to the evaluate world position option for static meshes when RT shadows and/or RT AO is enabled.

Because of to distance between my camera and the character the WPO evolution effect is culled.

There are two culling options to disable, one of which is bugged and need a workaround to use with the foliage tool:
r.raytracing.geometry.instancedStaticMeshes.culling 0

The other is for static meshes not using the foliage tool (my specific issue)
r.RayTracing.Geometry.StaticMeshes.WPO.Culling = “0”

1 Like