from the latest maya api docs…my question is: are the global maya uvCoord and uvFilterSize shading variables “the shared global data” the docs talk about? And if so why wouldn’t that be mp safe? void MPxNode:: setMPSafe ( bool flag )
Description Set a flag to specify if a user defined shading node is safe for multi-processor rendering. For a shading node to be MP safe, it cannot access any shared global data and should only use attributes in the datablock to get input data and store output data.