Materials and shading networks in RenderMan for Blender are built up pretty much the same way as Blender's builtin built-in renderers, using the Shader Editor. However, there are some shortcuts and UI widget differences.
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You can attach materials (bxdf's) to selected objects using the shortcuts in the Object Context Menu:
This will attach the selected material to the selected objects in the outliner.
You can also attach a material to an object in the usual way under the material properties within the Material Properties tab 
.
Click New:
Then click Add RenderMan Nodetree
Nodetree and select the RenderMan material you want to use.
RenderMan shading networks will always terminate at with a RenderMan Material Output node.
Here's an example shading network:
Patterns
Pattern nodes can be connected to materials or other patterns in the usual way using shader editor Shader Editor 
. You can also connect pattern nodes in the material properties . or directly within the Material properties Tab .
For parameters that can take a pattern connection, a 
will be shown next to the parameter value. This is our connection widget.
Clicking on the widget will show our connection menu. Here's an example:
Patterns will be broken up into categories for easier browsing. The __EXISTING__ section will show existing nodes in the shader graph that you can connect to. If the parameter is already connected some more options will appear.
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