Importing a Material in 5.8

Summary

Usage Flags Overrides for Material Instances Imported from Older Engine Versions are Not Serialized/Packaged Correctly

What Type of Bug are you experiencing?

Rendering (Graphics / Niagara)

Steps to Reproduce

  • In 5.7, create a material instance, with a parent material that does not have the nanite usage flag enabled.
  • Use the material on a nanite mesh.
  • Upgrade the project to 5.8 (or migrate the mesh + material instance to a new 5.8 project).
  • Open the material instance and notice that the Nanite usage flag override appears to be enabled.
  • Add the mesh to a level, package and run the game, and open the level.

Expected Result

The mesh should display correctly in-game, not using the nanite fallback mesh, and there should be no warnings in the logs about missing usage flags.

Observed Result

Mesh uses nanite fallback in-game. Logging shows a warning about missing nanite usage flag despite showing as enabled in the editor.

Re-saving the material instance asset in 5.8 produces the expected result.

Affects Versions

5.8

Platform(s)

Windows