Overwriting Revit's internal coordinates
Revit 2010's new project basepoint UI explained
Importing CAD elements under a shared coordinate system
Relocating a project vs moving the project basepoint
Pinning the project basepoint
Exporting to CAD with the correct coordinate system
In this video I walk through the relationship of the default Revit coordinate system (both in Revit 2009 and 2010) to your geometry, and show how to overwrite that coordinate system as well as make sure that the new system pushes through to exported files. After that, we walk through a comparison of how Revit 2010 visualizes the project basepoint as well as the differences in the importing interface with the earlier 2009 version.