All 3Dmeshes and 3Dfaces in one layer are grouped into one X mesh , which gets the name of the layer (and the faces get their original color or the color of the 3Dmesh). If the mesh is included in a DXF block, then its name gets concatenated to the name of the block. Every DXF "insert" directive creates child X frame to the current parent frame. A number is added to the name of each child frame to guarantee it is unique in the frame hierarchy.
