Unlit textures looking washed out

[jamsutton]

Hi all,
I'm having an issue with my unlit textures in model viewer. I bake lighting into my textures for added realism, but when I load my glb files into model-viewer the textures seem to loose contrast and become flatter? I've read through issues on here and think it could be a bug where tone-mapping is being applied to the unlit texture?

Here's a screenshot of the unlit texture and how it displays in model-viewer. You can see the loss of definition, especially in the highlights.

Could there be a work-around?
Thank you,
Jam

[samaneh-kazemi]

Hi @jamsutton, thanks for reaching out. This is a known issue. We are currently applying tone mapping to unlit models, which we shouldn't.

[elalish]

Fixed in #3152. Once this is merged, please verify in our editor (since it uses the latest master).

[jamsutton]

Thanks so much for fixing this, amazing work you guys are doing! Some of my unlit baked textures use emissive textures (luminance with a black base colour) and not the KHR_materials_unlit extension - The tone mapping is being applied to emissive textures - is there an easy way to fix this? Thanks so much.

[elalish]

hmm, that's getting in pretty weird territory. What does emissive get you that unlit baseColor does not? We may need to add custom tone mapping support eventually...

[jamsutton]

Custom tone mapping option would be great! I have an AR app and use a few different ways of displaying AR content, they display an emissive texture and don’t seem to support the unlit extension. What is the best way of applying the KHR_materials_unlit extension to my model? I’ve tried to find a guide but haven’t had much luck…

[elalish]

It's a pretty simple piece of JSON in the glTF; the unlit spec shows what to do. I'd recommend the glTF VSCode extension for hand editing.