M | Model Element (T+ Model) | A Three Plus Model, Mesh, or Brep
Mm | Metalness Map (Bitmap) | The blue channel of this texture is used to alter the metalness of the material. (A System Drawing Bitmap or full file path to an image.)
A | Metalness (Number) | How much the material is like a metal. Non-metallic materials such as wood or stone use 0.0, metallic use 1.0, with nothing (usually) in between 0-1.
M | Model Element (T+ Model) | The updated Three Plus Model Element
