Today I found that meshes, which I exported as .FBX files have different UV than in Blender 2.8. Previously there was no such issue. I made some tests and found that if you will use .OBJ format instead, UV exported correctly. Also, I tested models, which I previously exported correctly in older versions of Blender 2.8 and they also have issues with UV now. Anybody else has such issues? How to solve this or I have to wait an unknown amount of time until this will be fixed? Can’t use OBJ only because meshes have rigs/armature.
I did more research and found the following details:
If I repack UV and try to export it, I will get same results in FBX, like with old layout - looks like some old UV existed somewhere in .blend file and it exports instead of those, which shows in Blender 2.8.
I also tried to use Blender 2.79 and append problematic object in it - appended object also had the wrong UV, like in FBX export. Making UV unwrap again also didn’t help - old UV still exported somehow. Applying modifiers manually also didn’t help.
Finally found the issue. For some reason, some objects have multiple UV Maps (I didn’t create them manually, so I didn’t know that they existed, maybe some addon created them) and on some objects, not the first UV Map was selected. And when I exported such objects, I got first UV Map selected, which contained the wrong UV (because I did it for others). I removed all unnecessary UV Maps and it fixed an issue.
yeh as of now there is no manual way to re-arrange blender UV maps. In UE4 if you import as .fbx (grouped) it will only pick the first 2 UV maps, if non-grouped it will keep all the UV maps but your objects will be seperate (usually you want to use .fbx to pack multiple .obj’s into 1 and keep their respective UV maps).
There is an add-on called “Asset Creation Toolset for 2.8” which, has many cool tools, allows you to change the UV name/order: https://gumroad.com/mrven?recommended_by=library#
Thanks for posting your research findings here!!
I am having a similar issue and I’m pretty new to Blender. Could you expand on where / how you found / removed the multiple UV maps?
The UV maps are shown in the object data tab of the properties panel.
Isn’t there any way to avoid having to delete the additional UV map? I had the same issue even when my new UV map was active and the other was disabled.