OpenSceneGraph

OpenSceneGraph can read directly from the GRASS database when the GRASS-GDAL plugin was installed.

Example:

 GRASSDATA=$HOME/grassdata/nc_spm_08/PERMANENT
 export GRASSDATA
 
 osgdem --xx 10 --yy 10 -t ${GRASSDATA}/cellhd/landuse96_28m \
        --xx 10 --yy 10 -d ${GRASSDATA}/cellhd/elevation \
        -l 4 -v 0.1 -o north_carolina.ive
 # you can already watch while the conversion is still running:
 osgviewer north_carolina.ive