...

PrmanSignalVisualizer has two modes - select port and signal input.  The signal input mode is not available for materials created with NetworkMaterialCreate in Katana 3.2+.

Material Location 

The scenegraph location of the material that you wish to inspect

...

"Select Port" mode-only parameters

Set from Scenegraph Selection Selection

With a material location selected in the Scene Graph, press this button to populate the Material Location, Shading Node, and Output Port parameters.  These

Shading Node

The name of the selected pattern. This will be automatically filled when you select an output port in the window that pops up when the Set from Scenegraph Selection button is pressed pressed.

Output Port 

The name of the selected output. This will be automatically filled when you select an output port in the window that pops up when the Set from Scenegraph Selection button is pressed pressed.

Clear Node and Port 

This button will reset the read-only Shading Node and Output Port parameters

Using the node

Select Port mode

1. Add the node

...

1. in the Node Graph downstream of where your material is created
2. Select a location in the Scene Graph - a material location or a location with a local or inherited material assigned
3. Press the Set from Scenegraph Selection button on PrmanSignalVisualizer
4. A window will pop up and display the shading network of the material at the selected location.  The nodes are automatically laid out by Katana, so the layout may not match the layout of your original material.
5. In this window, choose the output of a shading node that you wish to visualize
6. All locations with that material assigned will now render with the isolated signal

Signal Intput mode

The signal input mode is not available for materials created with NetworkMaterialCreate in Katana 3.2+.  There is no way to connect an output of a shading node to a node outside the NetworkMaterialCreate group.

1. Add the node in the Node Graph downstream of where your material is created.  Right after the NetworkMaterial node works well for this mode.
2. Wire a shading node output into the signal input of PrmanSignalVisualizer
3. Add the scenegraph location of the material into the Material Location parameter
4. All locations with that material assigned will now render with the isolated signal

...