Hey ambi
A little experimenting today. Using Solidworks. Not looking at assemblies which seem to work ok, but single parts which contained multiple bodies.
Start with the basics. Cube with a material assigned (thus the colour to the entire part) and a colour override assigned to one face.
Saved it as a step file, imported via STEPper no worries.
I added another cube to the part in Solidworks, not touching the first. Two detached cubes. The second cube, because it’s still part of the part, would have the overall part appearance by default. I set another colour to one of its faces.
Imported them via STEPper. Lost the colour of the face on the first part, second one came through. I could separate by loose parts. This didn’t bring back the missing face colour of course.
Now I added two more bodies to the part which were not merged in Solidworks but each shared a face with one of the two cubes. I assigned both bodies a new colour, and one face on each a new colour too.
These came into Blender as one mesh which could only be separated by loose parts into two - the pairs with common faces had been merged. All individual face colouring was gone.
Importing the step files into Rhino they were exactly as designed.
So I’m guessing this is either a limitation of OpenCASCADE or some kind of configuration problem with how you’re using it.
STEP files attached if you feel like having a play. In Rhino this is how they look:
This feels so close to working. I’m on the verge of getting one of my grads to build a blender materials library that matches the Solidworks appearances tree, in the hope we can match by STEP colour for a much simplified export/import/rig/render workflow. This issue is the only thing stopping me at the moment, you’ve got everything else working so well (especially the ability to reload and bring in a hierarchy)
Keep up the great work!
2CubePairsSpaced.STEP (62.2 KB)
2CubesSpaced.STEP (26.6 KB)
SimpleCube.STEP (14.2 KB)