A USD file with as much syntax details as possible

example.usda

#usda 1.0
(
    doc = """This is a docstring"""
    subLayers = [  # This is an in-line comment
        @./external_path.usda@,
        @/absolute/path.usda@,
        @uri:blah?extension=.usda:.usd:.usdc&meta=data@
    ]
)

class "_some_class_1" {}

over "root"
{
    def Xform "SomePrim" (
        doc = "Docstrings can also be single quoted"
        kind = "component"
        add references = @./base.usda@</Foo/Bar>
        prepend variantSets = "forwarding_variant_set"
        variants = {
            string forwarding_variant_set = "selection_1"
        }
    )
    {
        custom float some_property = 1

        variantSet "forwarding_variant_set" = {
            "selection_1" (
                payload = @some/thing.usdc@
            )
            {
                rel another = </Forwarder1.something>

            }
            "selection_2" {
                rel another = </Forwarder2.something>

            }
            "selection_3" {
                rel another = </Forwarder3.something>

            }
        }
    }

    def Mesh "card" (
        inherits = </_some_class_1>
    )
    {
        float3[] extent = [(-430, -145, 0), (430, 145, 0)]
        int[] faceVertexCounts = [4]
        int[] faceVertexIndices = [0, 1, 2, 3]
        rel material:binding = </TexModel/card/boardMat>
        point3f[] points = [(-430, -145, 0), (430, -145, 0), (430, 145, 0), (-430, 145, 0)]
        texCoord2f[] primvars:st = [(0, 0), (1, 0), (1, 1), (0, 1)] (
            interpolation = "varying"
        )
        double3 xformOp:translate:move.timeSamples = {
            0: (0, 0, 0),
            10: (0, 0, 20),
        }
        uniform token[] blah = ["thing"]

        def Material "boardMat"
        {
            token inputs:frame:stPrimvarName = "st"
            token outputs:surface.connect = </TexModel/card/boardMat/PBRShader.outputs:surface>

            def Shader "PBRShader"
            {
                uniform token info:id = "UsdPreviewSurface"
                color3f inputs:diffuseColor.connect = </TexModel/card/boardMat/diffuseTexture.outputs:rgb>
                float inputs:metallic = 0
                float inputs:roughness = 0.4
                token outputs:surface
            }

            def Shader "stReader"
            {
                uniform token info:id = "UsdPrimvarReader_float2"
                token inputs:varname.connect = </TexModel/card/boardMat.inputs:frame:stPrimvarName>
                float2 outputs:result
            }

            def Shader "diffuseTexture"
            {
                uniform token info:id = "UsdUVTexture"
                asset inputs:file = @./USDLogoLrg.png@
                float2 inputs:st.connect = </TexModel/card/boardMat/stReader.outputs:result>
                float3 outputs:rgb
            }
        }
    }

    def "typeless_child"
    {
        rel collection:Erasers:includes = [
            </Office_set/Desk_Assembly/Cup_grp/Pencil_1/Geom/EraserHead>,
            </Office_set/Desk_Assembly/Cup_grp/Pencil_2/Geom/EraserHead>,
            </Office_set/Desk_Assembly/Cup_grp/Pencil_3/Geom/EraserHead>,
            </Office_set/Desk_Assembly/Cup_grp/Pencil_4/Geom/EraserHead>,
        ]
    }
}