GLTFExporter: jpeg textures on export binary and embedImages=false cause validation error

Heya,

when exporting a material with a jpeg texture as a .glb with these options:

{
    binary: true,
    embedImages: false
}

The resulting .glb has a validation error:

      {
        "code": "IMAGE_MIME_TYPE_INVALID",
        "message": "Recognized image format 'image/jpeg' does not match declared image format 'image/png'.",
        "severity": 0,
        "pointer": "/images/0"
      },

It seems three.js exports the texture with the image/png mime type, regardless of what type the image actually is: ...,"images":[{"mimeType":"image/png","uri":"data:image/jpeg;base64,....

I had a brief look around but couldn’t find a way to set the mime type manually (but maybe I missed something…).

Working example: https://framer.tz1and.com/ Source: https://github.com/tz1and/image-framer/blob/main/src/index.js

Thanks!

[elalish]

I’m in favor of removing that option. Single-file GLBs are way more popular anyway, and if someone really wants to separate them they can always use gltf-pipeline or similar.

[852Kerfunkle]

@Mugen87 Thank you for resolving this bug.

And just to leave a related comment: #23592 works great. I suppose it would be nice to have some way of preserving the source image. Quality loss on jpeg recompression and all that. Maybe something akin to #23592 can be done - store the original texture in userData. Just an idea, I’m certainly happy with the status quo.