In this video Tore will explain how to export part of a WMS to GeoTIFF.
We need a total of 2 files to drape Orthophoto on terrain in the GeoTIFF format.
Remember:
* With a correctly created GeoTIFF, you will only have the .TIF file. However, if a .TFW file was automatically generated along with the .TIF file, you should include it in the folder along with all the other files to be zipped. The .TFW file contains spatial information.