Maybe a bit late on this one, but you could generate a terrain in GeoControl 2 with thin flow sediments or a similar erosion filter and then use the available selector to map a lava flow in the Vue materials editor.  I imagine that would work pretty well ...

This will get you started:

http://www.cornucopia3d.com/forum/viewtopic.php?t=7078&highlight=hdr

Yes, fantastic tutorial Artur.  I have only ever used NURBS (Rhino3d) which I love but this is very interesting because of the sculpting capabilities and their implications for Vue scenes.  Thanks so much for taking the time ....