Quoting Wolfgang Zillig <wolfgang.zillig@web.de>:

1. I want to achieve that invisible parts are hidden (the surface grid on the backside of the hill). Is this possible? I would estimate that this is not possible with the format svx but what about vrml or 3dmf?

What operating system do you use? You can edit vrml by hand - there is some transparency switch. To view 3dmf effectively, you need a MacOS and Geo3D.

2. The overlay of a (half transparant) jpg graphic would also be nice. Possible?

Not yet in therion, but I am actually working on it.

3. Can you reccomend a good viewer for vrml and 3dmf? I use at the moment the cortona vrml plugin for the internetexplorer but I'm not completely happy with it. I don't have a player for 3dmf at all on my computer.

Well, to be honest - I do not know any good player, therefore I started to work on my own :) Release is scheduled to april'06 :(

4. Is it possible to get a 3d model of the cave by lrud data? Up to now I did not type these into the input files?

Yes, it should be. S.