Encapsulates 2D parameterization for pattern generators. Allows transformations and selection of arbitrary variables bound to primitives. Uses a simple struct to represent bundled dataflow of outputs. @parameters
coordsys: Name of coordinate system transform (e.g. place3dTexture node in Maya). Standard coordinate systems : 'object', 'world', 'screen', 'NDC'.
traceSet: A trace set for occlusion testing
angle: Rotation angle around origin
scaleS: Frequency of feature in S
scaleT: Frequency of feature in T
offsetS: Offset from origin in S
offsetT: Offset from origin in T
invertT: Flip along T.