A procedural node that is capable of reading USD files.

Filename

The path to the USD file.

Namespace

Procedurals can declare a custom namespace. This can be used instead of the Procedural name to reference contents through absolute or relative paths. Multiple procedurals can share the same namespace by using the same custom name. Also, they can declare an empty name, and they will use the global namespace.

Object Path

Determines which USD primitives are rendered. When empty (default), it renders the whole USD file.

Override Nodes

Nodes inside the procedural can be replaced by other nodes with this parameter. This may be used, for example, to replace shaders in an existing .ass procedural. When the parameter is enabled, nodes in the immediate parent scope of the procedural will replace identically named nodes inside the procedural.

Debug

Enable extra debugging log output when loading the USD scene.

Threads

Sets the number of render threads.

Hydra

Uses Hydra to handle the translation of USD to Arnold, which makes the render consistent with the Hydra render delegate.

Operator Graph

To connect a Procedural Operator to an Arnold USD, you have to pick the operator ROP in the Arnold properties of the Arnold USD. Use the Arnold Properties top-level Arnold | Operator Graph parameter to pick the operator ROP, which can be anywhere in your scene.

_{Procedural Operator parameter in Arnold properties of Arnold USD}

File

Reads the bounding box from the Geometry File. This will only work for .obj and .ply files. Bounds for .ass files will be displayed if an .asstoc file is found alongside the .ass file.

Target SOP

Use an object in the scene to attach as a bounding box preview.

Display As

The assigned file can be displayed as Global Bounding Box, Bounding Box per Node, Points, and Polygons.

Proxy SOP

Provides a bounding box representation for visualizing the contents of a procedural when importing geometry into Houdini using a SOP.