Textured .obj and .glb / .gltf files not always working about rerun HOT 2 OPEN

I think the red color has to do with the texture for this mesh being single channel.

from rerun.

To extend on that, the issue is concrete that we're using TextureFormat::R8Unorm as a format here which as the name implies is a red channel texture.

To make matters worse, we actually also should probably take the OETF (gamma curve ;)) into account: Gltf specifies that any information in the texture data should be ignored and we should always assume the data is OETF encoded https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#metallic-roughness-material
It specifically talks about RGB values though, so it's a good bet this applies. The tricky bit of all this is that we quickly approach the the complexity of our tensor decoding and I believe we don't want to be that well-supporting on the mesh for the time being until we're in a situation where we can easily convert "tensors to textures" on the gpu as a separate, but still on-the-fly step. I.e. in the limit we'll need the ability to map all of our tensor decoding to a texture that also includes mipmapping, allowing us to have a very classic render pipeline from that step on and separating these concerns!).

That said, it shouldn't be too bad if for this unfortunate case of single-channel textures we just do the texture sampling in gamma space and convert it afterwards.

from rerun.