e: [GRASS-user] raster slices to volume

[Tomas Lanczos]

hanks,

I experimented a lot with this, Your way described below was the easiest 
and fastest but the result is not very satisfying for me becasue the 
produced "stripes" in the vertical cross section (see the picture). I 
also tried to extract points using r.random (3%), and interpolate using 
v.vol.rst, but after 12 hours of computing and reaching approx. 20% I 
gave it up. What is the best optimalization method for interpolation in 
v.vol.rst?

Thank You again

Tomas

Hamish wrote:
 > Tomas Lanczos wrote:
 >> I have contour maps converted to rasters (rock temperatures) in 
different depths (-500, -1000, -1500, -2000, -2500, -3000, -4000, -6000 
meters below sea level). What is the best way to interpolate them to one 
3d raster (volume)?
 >
 >
 > for evenly spaced raster slices first set the 3D region, e.g.
 >   g.region t=-500 b=-6000 tbres=500
 >
 > then use the r.to.rast3 module to make the 3D raster volume map.
 >
 > but you would need to interpolate intermediate levels for missing slices.
 > For -3500 you could use r.series method=average, for 4500,5000,5500 
you would
 > have to use r.mapcalc manually.
 >
 > v.vol.rst could be used to interpolate from 3D points, but 
RST+contour lines
 > usually is prone to artifact problems do to the uneven spatial 
distribution of
 > data points.
 >
 > see also the 3D help page on the wiki site:
 >   http://grass.gdf-hannover.de/wiki/Help_with_3D
 >
 >
 > Hamish
 >
 >
 >
 > 
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