Hello,
JFYI i have created a grass python module which uses the
vtkGreedyTerrainDecimation algorithm from VTK 5.4 to create a TIN from
a raster height map.
This algorithm can approximate a raster hight map based on several criterias
i.e.: the number of triangles used to approximate the height field of
the raster map.
It may be quite useful for TIN creation and visualization pruposes of
large raster height maps.
The created TIN is written back to the grass vector database.
The module is called r.to.in.py. An example with screenshots is available here:
http://code.google.com/p/vtk-grass-bridge/wiki/rToTinResults
The Code is available here:
http://code.google.com/p/vtk-grass-bridge/source/browse/trunk/Examples/r.to.tin.py
Have fun
Soeren