Hi there,
I know this is a common question, but it did actually use to work for me and suddenly it doesn’t anymore.
If anyone could quickly help me out with this, I’d be more than grateful. I want to submit my work for a competition and the deadline is soon. 
In version 4.12.5, with which I started my project, I was able to important one obj mesh with several submeshes. I didn’t merge the single meshes in Maya and made sure they all had the same pivot point and aligned in the center. Then I selected all of them and exported them as one file. This worked for 4.12 and I was able to place a tree in my project and assign different textures (material slots) to the submeshes, without having to worry that I accidentally misclick and place the branches far away from the tree trunk.
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Besides I need this feature, because parts of the tree are animated, but obviously I don’t want the entire tree (including trunk) to wobble around.
Now I transferred my project to 4.15. In other projects I noticed that this feature didn’t work anymore, whenever I imported objs as I described above it would create several static meshes in my content browser. However, when transferring this project to a later version of unreal, the submeshes remained. I backuped my files, replaced them with new meshes, because I had some changes to make to the mesh, and then reimported the assets (I made sure the files are named the exact same). When I do this, unreal will give me one single mesh without any submeshes and ignores all the other material slots.
I tried reimporting my backuped files that did work with the submeshes, and everything went back to normal. I’m confused. Maybe it’s not even a problem with the version? But what am I missing? Any ideas?
