In the UE5 case, we end up seeing very harsh lines in both the gradient and the distance to nearest surface examples whereas the results in 4.27 appear smooth. 

It was also interesting to observe changes in the distance field material results between Lumen GI and No GI.

Steps to Reproduce

In Unreal 4.27.2, create a new, blank, Blueprint project, and in the project settings activate Generate Mesh Distance Fields.

  1. Create a new material, M_DistanceToNearestSurface
    1. The material should be translucent and default lit
    2. Divide DistanceToNearestSurface by 500, saturate that result, and output it to Emissive Color
  2. Create a new material, M_DFGradien.t
    1. The material should be translucent, and default lit
    2. Normalize the output of DistanceFieldGradien.t and output that to Emissive Color
  3. In a new, empty level create one sphere, and one plane, which are at the same point in the world.
    1. Scale the plane up to 10, 10, 1
    2. In the plane's setting, uncheck "Affect Distance Field Lighting"
    3. Drag M_DistanceToNearestSurface from the content browser onto the plane
  4. Duplicate that setup and shift it over so the planes do not overlap
  5. Drag M_DFGradien.t onto the newly-created plane

Save the level, and exit Unreal.

Duplicate the project folder, appending "5" to the folder name. Open the new project folder, and change the engine version of the .uproject file to UE5.

Open the new UE5 project, change the Reflection and Dynamic Global Illumination Methods to Lumen. 

Open the test level, and compare the results with those from 4.27.

Have Comments or More Details?

There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-150397 in the post.

Login to Vote

ComponentUE - Rendering
Affects Versions5.0
Target Fix5.2
CreatedApr 27, 2022
UpdatedSep 22, 2022