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raster3dintro.1grass

3D Raster data (voxel) in GRASS GIS

3D Raster (voxel) import

The module r3.in.ascii supports generic x,y,z import. Alternatively, voxels are be interpolated from 3D point clouds as transformed from 3D point vector data (v.to.rast3). Always the full map is imported.

Voxel region settings and 3D MASK

GRASS 3D raster map processing is always performed in the current 3D region settings (see g.region), i.e. the current region extent, vertical extent and current 3D resolution are used. If the 3D resolution differs from that of the input raster map(s), on-the-fly resampling is performed (nearest neighbor resampling). If this is not desired, the input map(s) has/have to be reinterpolated beforehand with one of the dedicated modules. Masks can be set (r3.mask).

Voxel operations

Powerful 3D map algebra is implemented in r3.mapcalc.

Voxel conversion

3D vector point data can be converted to a GRASS 3D raster map (v.to.rast3). Layers from a 3D raster map can be converted to a 2D raster map (r3.to.rast).

Voxel interpolation

From 3D vector points, GRASS 3D raster maps can be interpolated (v.vol.rst). Results are volumes, or 2D raster maps can be also extracted.

Voxel export

GRASS 3D raster maps can be exported to VTK (r3.out.vtk). VTK files can be visualized with the VTK Toolkit, Paraview and MayaVi. GRASS 2D raster maps can be exported to VTK with r.out.vtk, GRASS vector maps can be exported to VTK with v.out.vtk.

Alternatively, GRASS 3D raster maps can be imported and exported from/to Vis5D (r3.out.v5d).

Finally, export to 3D ASCII is also possible (r3.out.ascii).

See also

Introduction to GRASS raster map processing

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