In my work flow I have ‘families’ of static mesh actors that have different geometry but use same sets of materials. Building wall with one window, similar wall but with two windows and so on, you get the idea.
When I am building my scene I duplicate static mesh actor in the scene and just replace static mesh in the details panel. Up to 4.14 all was working just fine.
In 4.15, replacing static mesh in the details panel or via right click menu will reset all the materials to default ones that mesh has assigned.
Short demonstration can be seen here http://imgur.com/a/lWR4d
Steps to reproduce:
- Duplicate static mesh actor in your scene
- Apply different material than it currently has.
- Drag different static mesh into corresponding slot in the details panel. It is possible to replace static mesh with rightclicking on the actor in the scene and then clicking on ‘Replace selected actor with’.
I’ve tested this bug in my work project, clean project and also on different computer with same results.