Miscellaneous Changes

• The shelf's IPR button has a submenu to select the IPR resolution. By default, picking a new resolution with restart the IPR, but this can be disabled by toggling "Restart IPR on change".
• IPR does not have to be stopped to render again. Just press the IPR button again to force updates when geometry positions are changed.
• Added improvements to the way the IES browser handles files.
• There is a new "Rebuild Shelf" menu item in the RenderMan menu, under Diagnose. This will destroy the previous shelf and rebuild it. This is useful if after installing or uninstalling your shelf has been corrupted. Note this does not rebuild previously added user options.
• The intensity of IES profiles has changes to be more in line with the real world. A new "IES Ignore Watts" switch has been added to the Advanced tab of the render globals, in a Compatibility section, should you wish to revert to the previous behaviour.
• The preset browser now includes a preference pane.
• The preset browser now stores all its assets inside a "RenderManAssetLibrary" directory. If the directory doesn't exist, it will be created for the user.
• OSL shaders can now register themselves as a node in the hypershade. To do this, a nodeid and classification string needs to be added to the shader's metadata. Ex:

 shader OSLShaderExample
[[int rfm_nodeid=1200405, string rfm_classification="rendernode/RenderMan/pattern"]]
(
        float f1 = 0.2
        [[string page="Float Input1", float min = 0, float max = 1]],
        float f2 = 0
        [[string page="Float Input2", float min=0.0, float max=1.0]],
       ...
)

• Bxdf "PxrBlack" is assigned to mesh lights by default. This can be overridden by assigning a Bxdf to the light or the geometry source. PxrBlack is assigned to prevent secondary scattering from the light itself.

• txmake no longer manipulates input images to conform to the OpenEXR latlong specification. An input image is converted directly to an OpenEXR format latlong texture with no image manipulation. The -extraargs exrlatlong flag is no longer needed or supported.

• Originally introduced in 20.6 as an option, PxrPathTracer now tracks the diffusedepth and speculardepth separately from each other based on which lobe of the BSDF is sampled. Previously rays that have both diffuse and specular contributions increment both the diffuse and specular depths. The new behavior is more intuitive and produce expected results when adjusting the trace:maxdiffusedepth and trace:maxspeculardepth attributes. This comes at the cost of, in some cases, effectively doubling the number of indirect ray bounces which can cause look differences and/or increase render times.

Known Limitations

RenderMan for Maya

• Modifying light visibility while in IPR mode does not change light visibility
• Maya fluids will currently only render if you add RenderMan volume controls. Select the fluid shape and in the AE, do Attributes->RenderMan->Add Volume Controls
• Creating a mesh light during IPR will retain the old geometry (non-mesh light). A refreshed IPR session will remove the old geometry.
• Prior versions of RenderMan for Maya are not compatible with RenderMan 21.0. Trying to load the version 20.0 plugin with RenderMan Pro Server 21 installed will cause the following warnings: "rfm Warning: skipping unknown Slim keyword: requires" when loaded. The 20.0 plugin will not function correctly.
• Preset Browser : pattern nodes with array parameters and displacement patterns will not be correctly saved. This will be corrected in 21.1.
• Deselecting "Receive Shadows" does not work.