[GRASS-dev] nviz: overlay two color raster maps?

[Hamish]

Markus wrote:
> Masking in NVIZ didn't have to seem an effect.
> 
> Any ideas?

Yeah, make a surface attributes mask & transparency map but with
values of 255 not 0/null. It's a bit of a pain but I've made
this work in the past. It seems like the sort of trick I would
have instantly added to the wiki/man page/ML, but I don't see
it right now (I only had a very quick look).

mmm. coming back to me now. have a look around bug #111 r.los
on WinGrass- with a 3D view of visibility from a spot in an
Italian valley draped over LANDSAT. screenshot is dated 1/1/10:
http://bambi.otago.ac.nz/hamish/grass/bugs/rlos_onearth.jpg

r.mapcalc rlos255 = "if(isnull(rlos), 255, rlos)"

I've still got the nviz state file and mapset's .bash_history
if you are still stuck & want to try and recreate what I did.

cut from the nviz state file:

7 7
1 1
poly
grid_wire
gouraud
surf*1262344157
map dtm at PERMANENT
0
map rlos at paolo
0
map rlos255 at paolo
0
map rlos255 at paolo
const 60.000000
unset
#888888
0.000000 0.000000 5.000000


ah, ok, that is a second raster surface added 5m above the
landsat DTM.

let me know if you are still stuck and I'll package up the
mapset as a tarball as an example.


Hamish