Glb weird flipped uvs?

hi my model has flipped UV when i upload my GLB file but inside blender everything looks fine , can you help ?

Hello, I can’t find the model in your profile. Did you delete it?

yes sorry, it’s this one now : Nil Sunna - 3D model by seimax [f89e98c] - Sketchfab

uv are still flipped so i flipped the maps

Hi @seimax

GLTF (GLB) stores textures in a different way than other tools like Blender or Sketchfab. When converting to GLTF, the model needs to have its texture flipped to match GLTF specification, and this operation can be done by two means:

  • Flip the image vertically
  • Invert the UVs on the vertical axis

Both ways lead to a valid glTF, and the model displays fine in glTF viewer or when loaded in other tools.

Blender GLTF exporter chose to flip the UVs.
On Sketchfab we prefered to flip the images because we don’t want to alter the source 3D data.

So when you export your model using Blender GLTF exporter, you get the UVs flipped, which explains why the texture is upside down when you add it through Sketchfab editor.
For textures provided with the model, it’s fine as they get flipped automatically by our processing. (Both the textures and the UVs are flipped, so everything aligns as expected)

In order to get a proper result, I would suggest to upload the .blend file directly, as our processing supports this format.

I hope it helps :slight_smile:

Edit: if you are curious about the code, it is available on github and the flip happens here


Good to know ! Thanks a lot for the informations i didn’t know it was supposed to behave like this, since i’ve flipped all my maps everything looks fine now thanks a lot !

When uploading mesh.glb from Blender, all UV Maps receives flipped while making use of PBR/Standard Material with texture.