See the following UDN for a good visual explanation of the bug:


Seems like this was introduced around CL 5639656.

Steps to Reproduce
  • Create 3 cubes
  • Assign each cube a different material (red, green, blue)
  • Select the 3 cubes and merge them to create a new static mesh with 3 sections that each reference one of the material
  • Place an instance of this new static mesh (let's call it merged mesh) in your scene
  • Select it and create a proxy mesh, notice how the proxy mesh is identical to the merged mesh.
  • Now, change the assigned materials on the merged mesh for each section to 2, 1, 0 (or any other combination really)...
  • Create a new proxy mesh - notice how the colors assigned to each cubes doesn't match those found in the merged mesh.

Have Comments or More Details?

There's no existing public thread on this issue, so head over toAnswerHub just mention UE-77524 in the post.

Login to Vote

ComponentTools - MeshEditing
Affects Versions4.22.3
Target Fix4.24
Fix Commit8214461
Main Commit9420574
Release Commit9552237
CreatedJul 18, 2019
ResolvedAug 22, 2019
UpdatedOct 28, 2019