This node creates an attribute which causes material textures to stick to surfaces deformed using other operations.
Rest can get the rest position in one of two ways:
By reading a file.
By attaching a second input.
The first input is the deforming geometry. The second input (or file) is the rest position data, which is typically a static, non-deforming surface. If no second input or rest file is provided the first input will be used for the rest values. This is useful when the rest SOP is used before deformation in the pipeline.
The topologies of the two geometries should match.
All primitives support the 'rest' attribute, but, in the case of quadric primitives (circle, tube, sphere and metaball primitives), the rest position is only translational. This means that rest normals will not work correctly for these primitive types either.
The 'rest' attribute is exported to RenderMan as the 'Pr' attribute. This is output for all surfaces as a 'vertex float attribute'.
Rest normals are required if feathering is used on polygons and meshes in Mantra. NURBs/Beziers will use the rest position to compute the correct resting normals.