Sdf Plugin

Sdf plugins allow OpenUSD to transparently read and write foreign file formats. guc comes with its own plugin, usdGlTF, which needs to be enabled with the GUC_BUILD_USDGLTF CMake option.

After building, the plugin has to be copied to the USD installation tree:

cmake --install . --component usdGlTF --config Release --prefix <USD_INSTALL_DIR>/plugin/usd

Following file format arguments are exposed:

Name	Type	Default Value
emitMtlx	bool	false
skipValidation	bool	false

Transparent file I/O

With the plugin installed, glTF files can be opened with USD tooling such as usdview and usdcat.

Arguments may be encoded into the path as follows: usdview Asset.gltf:SDF_FORMAT_ARGS:emitMtlx=true

Composition arcs

glTF files can further be referenced by USD layers, optionally with arguments, as documented in Dynamic File Formats.

#usda 1.0

def "Root" (
    references = </Params>
    payload = @./Asset.gltf@
)
{
}

def "Params" (
    emitMtlx = 1
)
{
}