Import 12D File
This function imports project data from the 12D modeling program
into Carlson format. Linework geometry from the 12D file is drawn
as polylines. The routine also draws any text, symbols and points.
Project data for centerlines, profiles, sections, pipe networks and
surfaces are saved into Carlson project files.
Keyboard Command: 12d_import
Prerequisite: A 12DA file
to import