If SketchUp is OK (assuming it's the FREE part of FOSS you're looking for), it's photomatch functionality is really handy for building and placing models, assuming there are linear edges in your background scene. There's some good tutorial videos on YouTube.
Generally, I've found you really don't want to try to model anything you can take a photo of. Just model the new stuff and composite it in with Photoshop/Gimp/etc. Marc Pfister _______________________________________________ Geowanking mailing list [email protected] http://geowanking.org/mailman/listinfo/geowanking_geowanking.org
