the sequence is as follows :
• TEXT FILE from land survey
done with topographic instruments
• POINT CLOUD
• TRIANGULATION
• 2D DESIGN ALIGNMENT
• 3D TERRAIN PROFILE
produced by the INTERSECTION
of the 2D DESIGN ALIGNMENT
with the TERRAIN MODEL
• 2D TERRAIN PROFILE
obtained by SPREADING the
3D TERRAIN PROFILE
in the XY PLANE
• 2D DESIGN PROFILE
• 3D DESIGN PROFILE along which to "extrude" the sections
of the various components of the road and the sections that generate the volumes to add and subtract from the 3d terrain model,
made taking into account 2D DESIGN ALIGNMENT (X and Y) and 2D DESIGN PROFILE (where Y becomes Z)
• POSITIONING along the 3D DESIGN PROFILE of all the SECTIONS
• LINKING all these SECTIONS with the LOFT command
• CONVERSION of TRIANGULATION made with 3D faces, into a 3D SOLID
• 1 ADDITION and 1 SUBTRACTION of SOLIDS
• every thing, made with only few LISP commands
