hi sorry for late reply.
I checked F3D and as you said it has the same behavior as VTK.
I tried the first method and it loads the texture but not the way I want the textures to be loaded. I think it’s because the texture coords need to be consistent with what’s specified in .gltf file.
I think the workaround is to get the model using other formats(.obj for example). Or I need to dive into how .gltf is handled behind the scene and see if there’s a fix.
Thanks for your time and help anyway.