On the site http://frcprogetti.com are (section 'approfondimenti') published  interesting tutorial for revit architecture, and some rendering obtained with it.link

How can we draw contours in atocad 2004 or 2007

Surveyors, land-use engineers, and architects often need to create
contours that show the elevation of land. You can easily do this using
the SPLINE command.
First, set an easily visible point style. Choose Format > Point to do this. (This is the PDMODE system variable.)
Then
use the POINT command to insert the points into the drawing. If you
have a list of points in an external file, you can create a script file
that sets PDMODE, starts the POINT command, and inserts all the points.
You'll need to strip the external file of everything except the points
and then format them (in a text-only file) so that each one is on a
separate line.
Finally, use the SPLINE command. Use the NODE osnap variable to snap to the points.