The MPxDeformer class deform method's third argument is an MMatrix that represents the world matrix of the corresponding input geometry. The documentation does not specify how the deformer obtains this value. None of the default attributes in the node accept a matrix input. How does the deformer node get this value? Does it look for a reserved plug name (geomMatrix, perhaps?) and use it if it exists? If so, why isn't this behavior documented?
