[GRASS-user] Generate 3D raster from two surfaces

[grass at sundquist.imapmail.org]

Hamish:

I looked at that before and the only thing I could think of was to use
r.to.rast3 by first generating a whole series of horizontal surfaces
with r.mapcalc, one for each foot of elevation, with each cell getting a
value of "1" if the "elevation" for that particular new surface lied
between the corresponding cell values of the top and bottom surfaces. 
Then taking those whole bunch of surfaces and feeding them to
r.to.rast3.  But that seemed pretty inelegant.  But it may be only way
to do it.  I would only be about 25 rasters to generate and then merge.

J.S.

On Sun, 20 Feb 2011 17:14:39 -0800 (PST), "Hamish" <hamish_b at yahoo.com>
said:
> J.S. wrote:
> > I want to generate a 3D raster (and display in nviz) that is
> > the volume between two 2D elevation rasters.  The application
> > is to visualize the subsuraface area that will be subject to
> > environmental remediation.
> 
> maybe this summary helps,
>   http://grass.osgeo.org/wiki/Help_with_3D
> 
> 
> Hamish
> 
> 
> 
>