- double (converted to float)
Katana only has four values for arbitrary attribute "scope": primitive, face, point, and vertex. For the most part, these scope values map to the RenderMan primvar tags as follows: primitive = constant, face = uniform, point = varying, and vertex = facevarying. Subdivision meshes support different interpolation of primvars with the "point" scope using the "interpolationType" attribute. If geometry.arbitrary.<group>.interpolationType is set to "subdiv", the primvar will be "vertex", otherwise the primvar will be "varying".
Here is an example OpScript showing how to set an arbitrary constant color primvar: