Optional per-point or per-segment parameters for Polyline Primitive that overrides the polyline primitive's global parameters. Define per-segment parameters by creating an instance of 
PolylinePrimitiveOptionalParameters, then calling the desired methods to define per-segment parameters, and finally passing the object to the polyline's Set or SetPartial method.  Initialize | Initializes default polyline primitive optional parameters. All per-segment parameters are initially empty. | 





