RenderMan for Maya allows users to import custom RenderMan shaders.
RenderMan shaders are handled like regular Maya shading nodes, except they
cannot accept connections from other Maya Material nodes. Imported RenderMan
shaders must have been created previously, either written in the RenderMan
Shading language or created using a shading tool like Pixar's Slim.
Once imported into
Maya the parameters of these custom RenderMan shaders can be animated, but
other Maya Materials cannot be wired into them. These RenderMan shaders can
be connected to a top-level shading group, but these connections are
constrained by the three available slots: surface, displacement, and
volume.
Any RenderMan shader can be imported into RenderMan for Maya. The
representation of the shader in Maya will have the correct UI, with all of the
shader parameters. To import a custom shader follow these steps:
1) Open the Hypershade.
2) Create a RenderMan Shader node.
3) Open the RenderMan Shader node in the Attribute Editor.
4) For the Shader parameter, browse for your custom RenderMan
shader.
5) Attach to objects in your scene.
Custom RenderMan
shaders will render correctly only when use with the RenderMan renderer.
They will not display correctly in other renderers, including Maya's
interactive UI.
For more information about using RenderMan shaders with RenderMan for Maya,
check out the
RenderMan
Shaders tutorial. RenderMan Studio users should also consult the Slim
documentation.
In addition to individual RenderMan Shaders, you can create a Custom Shading
Group, by attaching a Custom ShadingGroup attribute to individual
nodes (including specific passes). This is particularly useful for doing things
like creating global atmospheres.
You can add atmosphere shaders to your scene on a Global,
Per-Pass, or Per-Shading Group basis. You can Add Atmosphere Shader via
the Attributes menu of any Shading Group.
To add a Global atmosphere, create a new Custom Shading Group in the Advanced tab of
the Render Settings, under Default Shading, then select Add Atmosphere
Shader from the Attributes> RenderMan> menu, and, finally, add
an atmospher shader (a compiled .slo file) via the browse button for the new setting.
To do it “Per-Pass,” select the Pass Settings subtab in the Passes tab of
the Render Settings, click on the Add/Remove Settings button and add the
Custom ShadingGroup setting, then proceed as above. Alternatively, you can
add a Default Atmosphere Shader via Add/Remove Settings. You will need
to provide an explicit path to the shader using the latter method.