Material

• https://github.com/ousttrue/UniGLTF/issues/12

PBR

StandardShader

Unity RenderType Tag	glTFのmaterial.alphaModeプロパティ
Opaque	OPAQUE (デフォルトなので出力は不要)
Transparent	BLEND
TransparentCutout	MASK

ToUnity

ToGLTF

Unlit

https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Khronos/KHR_materials_unlit/README.md

"materials": [
    {
        "name": "red_unlit_material",
        "pbrMetallicRoughness": {
            "baseColorFactor": [ 1.0, 0.0, 0.0, 1.0 ] // baseColor
        },
        "extensions": {
            "KHR_materials_unlit": {} // flag. treat as unlit
        }
    },
  {
        "name": "unlit_with_fallback",
        "pbrMetallicRoughness": {
            "baseColorFactor": [ 1.0, 1.0, 1.0, 1.0 ],
            "baseColorTexture": { "index": 0 },
            "roughnessFactor": 0.9,
            "metallicFactor": 0.0
        },
        "extensions": {
            "KHR_materials_unlit": {}
        }
    }
]

Unity	KHR_materials_unlit
Unlit/Color
Unlit/Texture
Unlit/Transparent
Unlit/Transparent Cutout	material.alphaCutoff

ToUnity

ToGLTF