[GRASS-user] importing TIN mesh in GRASS

[Hamish]

Jitendra Kumar wrote:
> I have a TIN mesh from a simulation model that I want to
> bring in the GRASS. I was able to bring in the grid nodes
> in the vector map

excellent.

run 'g.region vect=grid_point_map' then 'g.region -p' and
then 'g.region -a res=...'. Adjust the resolution so that
the rows x columns is about 2000 x 2000 (adjust for your
needs.

Finally use v.surf.rst to make a surface.

This will be a *huge* improvement over a TIN.


> but am not sure how to create the triangles. I know GRASS
> has routines for triangulation, but couldn't find how to to
> import a already triangulated mesh.

Generally GRASS doesn't 'do' TINs because it doesn't need to.
It's raster surface engine has traditionally been its strongest
suit, and TINs grew out of a system with a strong vector engine
but a rather weak raster engine. i.e. they are a quick & dirty
kludge to compensate for lack of a strong raster engine. (ie
being able to efficiently handle massive grids on the fly)

none the less if you really want them have a look in the wiki &
addons, you might find some TIN tools there if you really want
them.  see also the v.delaunay module for triangulation code.


Hamish