[GRASSLIST:559] Re: raster 3d from DEMs

"Sören Gebbert" soerengebbert at gmx.de
Tue Apr 4 06:28:32 EDT 2006


> --- Ursprüngliche Nachricht ---
> Von: "Maciej Tomaszczyk" <mtom at pgi.gov.pl>
> An: <GRASSLIST at baylor.edu>
> Betreff: [GRASSLIST:555] raster 3d from DEMs
> Datum: Mon, 3 Apr 2006 12:25:05 +0200
> hello
> I created a couple DEMs from drillhole data, DEMs represent a geological
> boundary (e.g. Triassic/Jurassic), now i want  to fill space between this
> boundary and create a raster 3d. Is it possible to do, i suppose - yes,
> how to do it. Can anyone help me.

GRASS can only handle raster 3d data with one top and bottom elevation
But if you want to visualize the geological boundaries filled with data, you
use a combination of r3.mapcalc, r3.out.vtk and Paraview.

Create for each geological boundary a g3d map with at least 2 depths,

1. g.region t=100 b=0 tbres=50
2. r3.mapcalc "triassic = 1"
3 r3.mapcalc "jurassic = 2"

the use r3.out.vtk to export the data with top and bottom surface

r3.out.vtk -s input=triassic output=/tmp/triassic.vtk bottom=dem1 top=dem2

r3.out.vtk -s input=jurassic output=/tmp/jurassic.vtk bottom=dem2 top=dem3

Now visualize this data with Paraview
available at www.paraview.org

If you have some point  data within this geological boundaries, you can
interpolate them within a high resolution g3d map (depth > 40) with
and make slices of a specific elevation with r3.cross.rast.
The slices created with r3.cross.rast can be converted to g3d maps with

High res 3d region
g.region b="the lowest dem" t="the highest dem" tbres="a useful resolution"

Now use v.vol.rast to generate the g3d volume data, output is

extract the data with r3.cross.rast
r3.cross.rast input=generated_volume elevation=dem1 output=datadem1
r3.cross.rast input=generated_volume elevation=dem2 output=datadem2

Set a 3d region with only two depths
g.region t=100 b=0 tbres=50
r.to.rast3 input=dem1,dem2 output=triassic_data

Now export and visualize this data with Paraview
r3.out.vtk -s input=triassic_data output=/tmp/triassic_data.vtk bottom=dem1
Paraview --data=/tmp/triassic_data.vtk
Maybe this helps a bit

> regards
> maciej  
> Maciej Tomaszczyk
> Polish Geological Institute
> Geological Mapping Department

Analog-/ISDN-Nutzer sparen mit GMX SmartSurfer bis zu 70%!
Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer

More information about the grass-user mailing list