[GRASS-dev] NVIZ volume revisited

Hi,

with help from Roberto Flor (analysing the togl changes), I have
modified togl_flythrough.c to avoid atoi() crash, a rather simple
change.

Testing with Slovakia3d [1], now it
- goes into endless loop (but no longer crashes) with
    nviz el=dem500 vol=precip3d.500z50
  Maybe easy to fix?

- works fine with
    nviz el=dem500
  and loading the volume from menu.
  Note: the volume rendering is MUCH faster now. Funny.

We are getting close(r)...

Markus

[1] http://mpa.itc.it/grasstutor/data7/slovakia3d.tar.gz