CCL:Inside or outside of a polyhedron

["W. Todd Wipke" <wipke "at@at" SECS.UCSC.EDU>]

 There are a few quick checks:
 If the x coords of all vertices are all less than or all greater than the
 x coord of the pt, then the point must be outside.  Similarly for y and z.
 Find the center of an enclosing sphere for the polyhedron.  If the point
 is outside the enclosing sphere, then it is outside the polyhedron.
 Find the center of a maximal enclosed sphere for the polyhedron.  If the
 point is inside the enclosed sphere, then it must be inside the polyhedron.
 There is also the scheme of shooting out a ray from the point.  If it
 crosses the polyhedron surface an odd number of times, then it is inside,
 if an even number of times, then it is outside.
 -Todd Wipke
  Molecular Engineering Laboratory
  University of California
  Santa Cruz, CA
  wipke "at@at" chemistry.ucsc.edu