Developer Notes

No post process settings affect the SSR for translucency for enabled materials. This is because SSR there isn't a post process and is compiled into the material.

Description

Screen space reflections on translucent materials are not affected by post process settings. Any changes made to SSR settings in the volume will do nothing to a material that is set to the translucent domain and has SSR enabled on the material even on low settings.

Found in 4.19 CL# 4033788. Reproduced in 4.18 CL# 3832480 and 4.20 Main CL# 4088075

Steps to Reproduce
  1. Open the editor
  2. Enable "Show Engine Content" in view options in the content browser
  3. Create a reflective material with the opaque domain
  4. Save the opaque material
  5. Create a reflective material with the translucent domain
  6. In the translucent material set the lighting mode to "Surface Translucency Volume" and enable screen space reflections
  7. Save the translucent material
  8. Place two meshes into the scene and apply the opaque material to one and the translucent to the other
  9. Place box reflection captures on each mesh and scale down to fit the mesh you choose
  10. Set the reflection source type to "Specified Cubemap" and set the cubemap to "DefaultCubemap"
  11. Place a post process volume in the level and enable intensity and quality settings under the screen space reflection options
  12. Set both intensity and quality settings to zero
  13. Move the camera into the volume

Results:
The mesh with the translucent material will still show screen space reflections.

Expected:
Both materials will no longer show screen space reflections.

 

Steps for project:

  1. Open the attached project
  2. Move camera into the post process volume

Results:
The mesh with the translucent material will still show screen space reflections.

Have Comments or More Details?

There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-59571 in the post.

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Fixed
ComponentUE - Graphics Features
Affects Versions4.184.194.20
CreatedMay 24, 2018
ResolvedJul 31, 2018
UpdatedJul 14, 2021