As mentioned here 5 months ago, Roblox Studio has been having issues uploading TGA files through the 3D importer window. They just simply refuse to upload, with the error code -1:
However, PNG files do work fine, which means the issue is specific to the way the Editor handles TGA files, and not related to the model itself:
It is easy to reproduce the bug. Simply export a FBX with a TGA texture applied to it, and try to upload it.
Expected behavior
The textures should upload fine with the TGA textures applied. They used to apply properly but after certain updates to Roblox Studio, they stopped uploading entirely. Given that TGA is an industry standard, and the advantages it has given how it works with alpha channels instead of transparency, it’s a no brainer that it is a format that should not be discarded from Roblox
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