Are there any open source tools or libraries (ideally in python) that are available for performing lots of intersections with 3D geometry read from an ESRI shapefile? Most of the tests will be simple line segments vs polygons.
I've looked into OGR 1.7.1 / GEOS 3.2.0, and whilst it loads the data correctly, the resulting intersections aren't correct, and most of the other tools available seem to build on this work.
Whilst CGAL would have been an alternative, it's license isn't suitable. The Boost generic geometry library looks fantastic, but the api is huge, and doesn't seem to support wkt or wkb readers out of the box.
A bit late on answer but my python optical ray tracing programme pvtrace does exactly this. It would work like this:
1) Define polygon with a a list of points and make a Polygon object
points = [[0,0,0],[0,0.1,0],[0.1,0.1,-0.03],[0.1,0,-0.03]]
polygon = Polygon(points)
2) Get the intersection point(s) with a Ray object
ray = Ray(position=(0,0,0), direction=(0,0,1))
print polygon.intersection(ray)
来源：https://stackoverflow.com/questions/2549708/intersections-of-3d-polygons-in-python