DEM – Generating TIN from DEM Using MacOSX/Unix Tools

Question

I'd like to generate a 3d terrain model moving from a DEM dataset (currently in shp and GeoTIFF format).

As far as I understand it, the first step of the better path would be generating a TIN, but I can't find the way to do.

I found a lot of references to ArcGIS 3D Analyst, but no tools in MacOSX/Unix world.

Are there any?

Answer 1

You have a few options:

1. PostGIS 2 has support for TIN and some other 3D objects.
2. GRASS has support via an add-on. See this how-to document.
3. QGIS has an Interpolation plugin (see here)
4. Roll-your-own by importing the GDAL libraries into a 3D modelling package such as Blender (I do it this way a lot because I want interactive 3D model rather than for analysis - but you can always export the result to DXF or Collada).

All these approaches should be possible on Linux and I think on Mac too.

EDIT: I've just remembered another two for you: Terragen (commercial and free versions) and LD3T. LD3T theoretically works on Linux but they recognize that there are issues. I've only ever run it under Windows. It's worth noting that the Terragen format is readable/writeable by Blender, Landserf (see SS_Rebelious' post) and LD3T.