hi there so this was a problem from blender fbx files, but now when importing the .blender file directly im getting the same issue. What is weird is that it is not switching all the materials UVS… but most of them, like about 80 - 90% if i had to guess.
This is a huge problem to me now as i need to target uploading textures from the viewer api to these materials diffuse and you have no means to siptulate which uv channel to target from the api.
The UV’s on index 0 where for those uploaded diffuse textures , the UV’s on index 1 were for surface patterns and normals set in the editor. This worked great…
Now these got switched in sketchfab , so the surface patterns/normals are on index 0 and the diffuse UV’s are on index 1.
If i upload any textures they will just be assigned to index 0 by default and will be incorrect. @james had a hunch it might just use the uv index already assigned for that channel, but here is the catch … there are no textures assigned to that channel in the editor and so it is not possible to select the UV index to use
I just had to fix up a heap of models for virtual studio because of muddled uv channels, I was told this could be because of some reprocessing but i even tried to reupload those models and they were still broken. So i had to fix all of them by hand.
This model im currently talking about had its UV’s inverted this morning while reuploading… please somebody get to the bottom of this issue. the model has a huge amount of materials, editing is really painful and long and in this case causing the model to be usable by your api for lack of ability to target uv index of channels.