draping vector polygons over topography

[Ken Hickey]

G'day all   This is probably an basic question, but what do I have to do to get some vector polygons (defining a geological unit) to drape correctly over a DEM in #D mode. When I try, the topography "cuts thru" the vector polygons in 3D views. I though maybe I have to save the polygons as raster regions to get them to drape correctly, but when I use the "save as" option in the "tools" dialog box I get an error saying "dataset header file for region output doesn't exist". What does this mean? How do I convert a set of vector polygons intot raster regions?   Thanks in advance   Cheers Ken Hickey ------------------------------------------------------------------ Dr Kenneth Hickey Mineral Deposit Research Unit (MDRU) Department of Earth and Ocean Sciences University of British Columbia 6339 Stores Rd, Vancouver, BC  V6T 1Z4, Canada phone +1-604-822-3765; Fax +1-604-822-6088 email: [EMAIL PROTECTED]   .