RenderMan for Houdini exposes a powerful system of AOV creation and light transport output called Light Path Expressions. To simplify usage, many of the most common AOVs are available as presets in the ROP node under Displays Output.

To specify an AOV you should provide the following information to RenderMan:

...

Lighting passes are the typical passes used when making visual adjustments during compositing. We also provide per-lobe LPE to extract specific lighting information from Pxr materials. Note that these are additive and physically correct. Compositing operations involve addition and subtraction to retain what happens during rendering. Multiplication and division may introduce artifacts and is not recommended in post operations at the pixel level.

Shadow AOVs require that we compute the Beauty render and are used for compositing shadows onto filmed plates/footage

...