pbrSpecularGlossiness sample?

Hi, is there maybe an example available how to use pbrSpecularGlossiness shaders? For example to create ‘best practice’ json https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_pbrSpecularGlossiness#best-practices

{
    "materials": [
        {
            "name": "gold",
            "pbrMetallicRoughness": {
                "baseColorfactor": [ 1.0, 0.766, 0.336, 1.0 ],
                "roughnessFactor": 0.1
            },
            "extensions": {
                "KHR_materials_pbrSpecularGlossiness": {
                    "diffuseFactor": [ 0.0, 0.0, 0.0, 1.0 ],
                    "specularFactor": [ 1.0, 0.766, 0.336 ],
                    "glossinessFactor": 0.9
                }
            }
        }
    ]
}

[vpenades]

If you’re using the Toolkit’s MaterialBuilder framework, you can set a fallback material.

So let’s say you want to create a material that has a main “specular glossiness” material, and a “metallic roughness” fallback material that will be used if specular glossiness is not available.

var fallback = new Materials.MaterialBuilder("material1 fallback")
                .WithMetallicRoughnessShader();

var primary = new Materials.MaterialBuilder("material1 primary")
                .WithSpecularGlossinessShader()
                .WithFallback(fallback) // sets "fallback" material for this material.

And then you use the “primary” material with MeshBuilders.

There’s also a unit test here.

[vpenades]

I’ve commited some improvements and API changes… the whole MaterialBuilder framework was more buggy than I expected, so I had to rewrite some code. I’m still not 100% confident, so I’ll keep writing more unit tests for a few days before uploading new packages.

In the meantime, if you could use the latest changes directly, it could help me identify any other bug or use case.