Geometric Settings

When assigning instance attributes in Maya, they can be named like Primvars, where controls are found on the shape node. Or as attributes found on the transform node and variable per instance.

Example commands:

rfm2.ui.user_attrs.user_attrs_add(data_attr, nodelist, pdict) -> add to one or more nodes

rfm2.ui.user_attrs.user_attrs_del(data_attr, nodelist, attrlist) -> delete from one or more nodes

rfm2.ui.user_attrs.user_attrs(node) -> list all user attributes

Common

Name	Type	Default	Description
bake:activeudims	string	empty	Active udims for Integrator baking of texture atlases. Lists and ranges of udims can be provided in the string, for example: Attribute "bake" "string activeudims" "1001,1003,1005-1006". The default is "" which means all udims get baked.
bake:udimresolutions	string	empty	Udim texure resolutions for Integrator baking of texture atlases. Lists and ranges of udims can be provided in the string, for example: Attribute "bake" "string udimresolutions" "1001 512 512 1002,1003 64 32 1005-1006 16 16" If the string is empty (the default) then the Display Format resolution will be used.
grouping:id	int	0	Grouping id used for raytrace disambiguation purposes. Value range: 0 to 15.
grouping:membership	string	empty	Grouping membership used for linking.
identifier:id	int	0	Lower 32 bits of 64 bit object id.
identifier:id2	int	0	Upper 32 bits of 64 bit object id.
identifier:lpegroup	string	empty	Grouping membership used for light path expressions.
identifier:name	string	empty	Object instance name.
stats:identifier	string	empty	Identifier string used by the stats system when referring to this instance.

Shading

Name	Type	Default	Description
curves:widthaffectscurvature	int	1	Indicates whether curve width should be used when computing curve curvature. If turned off, only the curvature along the curve spline will be calculated.
lightfilter:subset	string	empty	Active light filter groups in lighting.
lighting:excludesubset	string	empty	Exclude light groups from lighting.
lighting:mute	int	0	Mutes light emission.
lighting:subset	string	empty	Light groups active in lighting.
Ri:Matte	int	0	Indicates matte object.
Ri:ReverseOrientation	int	0	Flip shading normals.
Ri:Sides	int	2	Geometry can be one or two sided.
shade:indexofrefraction	float	-1	Override material IOR for nested dielectrics.
shade:minsamples	int	1	Min Pixel Samples. For fine-tuning adaptive sampling.
shade:relativepixelvariance	float	1	PixelVariance multiplier for camera visible objects. For fine-tuning adaptive sampling.
trace:holdout	int	0	Indicates holdout object.
trace:intersectpriority	int	0	Raytrace intersection priority for nested dielectrics. Value range: 0 to 31.
trace:maxdiffusedepth	int	1	Maximum diffuse light bounces.
trace:maxspeculardepth	int	2	Maximum specular light bounces.
trace:reflectexcludesubset	string	empty	Exclude object groups from relections.
trace:reflectsubset	string	empty	Object groups visible to reflections.
trace:shadowexcludesubset	string	empty	Exclude object groups from casting shadows.
trace:shadowsubset	string	empty	Object groups active in shadows.
trace:transmitexcludesubset	string	empty	Exclude object groups from refractions.
trace:transmitsubset	string	empty	Object groups visible to refractions.
visibility:camera	int	1	Indicates if object is visible to camera rays.
visibility:indirect	int	1	Indicates if object is visible to indirect (reflection and refraction) rays.
visibility:transmission	int	1	Indicates if object is visible to shadow rays.

Added notes:

Emit Color Sets - Emits color sets assigned to objects, this is especially useful when rendering MASH objects with procedural coloring.

Prevent Polygon Cracking - Typically it's expected that you displace subdivision surfaces. However, should you need to displace a polygonal surface with "hard" normals, this option will attempt to prevent the object from coming apart once it's displaced.

Emit Face IDs - This is allows surfaces to make use of Ptex texturing.

Reference Object - _WPref and the place3d with the reference object should be parented below the object that you are animating. _WPref is necessary for instances to have the texture stick in the same way. However, during IPR if you move/translate your object and it does not deform, it is not re-evaluated and the _WPref is not updated if only the transform has changed. You will only see the correct values if you restart the render or trigger an update on the mesh somehow (for instance, tweaking the displacement bound).