Example Usd files and mapping pair files

Simple Example

A very simple setup can be found in In the <REPO_ROOT>/files folder.

Before launching a Usd related software, you'll have to set these env vars:

export AR_SEARCH_PATHS=${REPO_ROOT}/files/generic
export AR_SEARCH_REGEX_EXPRESSION="(bo)"
export AR_SEARCH_REGEX_FORMAT="Bo"

The source setup.sh bash script in the root of this repo also does this for your automatically. After that load the box.usda in the application of your choice. Make sure to load box.usdaand not /path/to/repo/box.usda as the resolver only resolves paths that use the search path mechanism. You should now see a cube. If you set the resolver context to the mapping.usda file, it will be replaced to a cylinder.

Production Example

A larger example scene setup might looks as follows:

• The following files on disk:
  • /workspace/shots/shotA/shotA.usd
  • /workspace/shots/shotA/shotA_mapping.usd
  • /workspace/assets/assetA/assetA.usd
  • /workspace/assets/assetA/assetA_v001.usd
  • /workspace/assets/assetA/assetA_v002.usd
• The AR_SEARCH_PATHS environment variable being set to /workspace/shots:/workspace/assets

In the <REPO_ROOT>/files folder you can also find this setup. To run it, you must set the AR_SEARCH_PATHS env var as follows.

export AR_SEARCH_PATHS=${REPO_ROOT}/files/generic/workspace/shots:${REPO_ROOT}/files/generic/workspace/assets

And then open up the shots/shotA/shotA.usd file and set the resolver context mapping file path to shots/shotA/shotA_mapping.usd.

In Houdini this is done by loading the shot file via a sublayer node and setting the Resolver Context Asset Path parm to the mapping file path in the Scene Graph Tree>Opens the parameter dialog for the current LOP Network button.

You'll see the box being replaced to cylinder.

Content structure

Content of a USD file located at /workspace/shots/shotA/shotA.usd

#usda 1.0
def "testAssetA" (
    prepend references = @assetA/assetA.usd@</asset>
)
{
}

Content of the USD file located at /workspace/shots/shotA/shotA_mapping.usd

#usda 1.0
(
    customLayerData = {
        string[] mappingPairs = ["assetA/assetA.usd", "assetA/assetA_v002.usd"]
    }
)

Content of the USD files located at /workspace/assets/assetA/assetA.usd and /workspace/assets/assetA/assetA_v001.usd

#usda 1.0
def Cube "asset" ()
{
    double size = 2
}

Content of the USD file located at /workspace/assets/assetA/assetA.usd and /workspace/assets/assetA/assetA_v002.usd

#usda 1.0
def Cylinder "asset" ()
{
}