[GRASS-user] Vector Overlay Map Disappears in 3D View

[Rich Shepard]

On Sat, 14 Jan 2012, Anna Kratochvílová wrote:

> in 3d view mode you can display points and lines only.

Anna,

   I did not know this, and don't recall reading it anywhere. I'm surprised
that nviz does no better. Of course, it's been a number of years since I had
need to drape vector maps over DEMs and I have no recollection of whether
there were any polygon maps at that time.

> The only solution I can see is quite complicated and I'm not sure if it
> would look good. You could create new raster map from the DEM which has
> different cell values where the lakes are placed. This means to rasterize
> the vector map lakes and then somehow combine this raster and DEM
> (r.patch?) and then change color rules so that the lakes are blue. Then,
> you display the original DEM in 3d view and change its color to use colors
> from the new raster. If the lakes are flat enough, it could help. Hope you
> understand what I mean.

   Looks like too much work for our needs. I'll work with r.profile and learn
how to place transects on the DEM map then use PSTricks to produce the plots
of the transects.

   The 3D perspective may be easier for a non-technical audience to
comprehend, but without the reservoir filled in the map is useless.

   Unless, ... I'll try making a copy of the lakes map and converting that to
a raster. There is really only one lake, the reservoir in the center of the
screenshots I provided. I'll have to see if I can then overlay that raster
lake with the DEM so there's only one raster file in the 3D map stack.

Thanks,

Rich