When using a DM that has Crumble Smallest and Impact damage enabled there will be instances where the residual mesh before fracture is left behind. What appears to happen is there is a force large enough to crumble the chunks but this does not wipe the original unfractured mesh from the view. This residual mesh has no collision and cannot be removed from the scene.

This also only happens within a specified range of the mesh as well. If the mesh is far enough away from what would be the impact of the chunks that are crumbled this will not affect the others. Disabling Impact damage or Crumble Smallest will resolve this issue.

Attached: Video demonstration and project with this set ups for comparison.

Steps to Reproduce

1. Open UE4
2. Create a DM and fracture it
3. Enabled the Flag Crumble Smallest
4. Enable Impact damage with damage to 1 and depth to 1
5. Use a projectile to apply damage (line trace with apply radial damage)
6. Place several of these in very close proximity
7. Shoot one of them.

Expected: When using crumble smallest anything that is hit with a force large enough to remove the chunks from the scene will be removed.

Results: The chunks are removed from the scene when enough force is applied but if enough force is applied the chunks are removed leaving behind the unfractured base depth mesh. This has no collision and cannot be removed from the scene.

Have Comments or More Details?

Head over to the existing Questions & Answers thread and let us know what's up.

Login to Vote

Cannot Reproduce
CreatedJan 28, 2015
ResolvedAug 2, 2016
UpdatedJul 14, 2021