Got it... it was a DFO error... Depending on the type of curve you choose, will determine the type of formatting you have to do. cmd.curve(bez=True, p=[(point1_XYZ), (point1_handle_XYZ), (point2_handle_XYZ), (point2_XYZ)]) but if you do: cmd.curve(p=[(point1_XYZ), (point2_XYZ), (point3_XYZ), (point4_XYZ)])