DESCRIPTION
Outputs Raster maps in VTK-ASCII format. Map's are
valid Raster map's in the current mapset. output is the name of
an VTK-ASCII file which will be written in the current working directory.
If output is not specified then stdout is used.
The module is sensitive to region settings (set with g.region).
Special features are that elevation, scaling, point/celldata and RGB Data are supported.
If no elevation map is given, the user can set the hight of the map by one value.
Pointdata or celldata are availible. Also scaling is supportet for this elevation value.
The RGB input requires 3 raster maps: red, green, blue - in this order.
The maps must! have values between 0 and 255, if not you will get lots of warnings!
More than 1 RGB Dataset (3 maps) is not supported. For now, RGB is only supported if
you choose an input map too, that may be changed in the future.
NOTES
This filter generates:
- structured points with celldata or pointdata if no elevationfile is given
- structured grid (not recommendet) with pointdata if a elevationfile is given
- polydataset with pointdata if an elevationfile is given (default)
And puts this in a simple VTK-ASCII file. Nor XML or
binary output are supported. It is possible to choose more then one raster map
to be written in the VTK-ASCII file. Each cell-/pointdata is named like the raster map it represents.
You can visualize this file with the
VTK Toolkit,
Paraview and
MayaVi which are based on VTK.
If you have a raster map with partly no data, use the threshold filter in paraview to
visualize the valid data. Just filter all data which is greater/lesser than the
choosen null value in the VTK-ASCII file.
If elevation map is choosen, a polygonal grid is created with quads,
but the user can choose also triangle strips or vertices.
These dataformats a documented at VTK Toolkit.
Difference between point- and celldata
r.out.vtk can export raster cells with different representations.
-
pointdata -- the cells/values are represented by the center of the cell.
Instead of cells, points are created. Each point can hold different values,
but the user can only visualize one value at a time. These points can
be connected in different ways.
-
celldata -- is only provided if no elevation map is given.
The cells are created with the same hight and width as in GRASS. Each cell
can hold different values, but the user can only visualize one value at a time.
SEE ALSO
r3.out.vtk
r.out.ascii
g.region
AUTHORS
Soeren Gebbert
Last changed: $Date$