Model coordinates are those coordinates that have not yet been transformed by any block inserts or views. One piece of model coordinate geometry can be contained in an unlimited number of block inserts. Most of the AcGi geometry methods use model coordinates. However, there are a few geometry methods that accept other coordinate systems.
When converting an entity's model coordinate geometry to world coordinates, the current net block transform is used. For example, if a piece of model coordinate geometry is in more than one block insert, then the net effect of being in the inserts is the net block transform.