[vtkusers] Trouble with ModifiedBSPTree

[David Doria]

I work about half time on two different computers, both running Ubuntu
11.10. On one of them, my code that uses ModifiedBSPTree to perform a
bunch of ray/mesh intersections works perfectly (in a test case of a
10x10 grid of rays aimed at a plane, all of the rays intersect the
plane, as they should). On the other computer, however, about half of
the exact same rays on the exact same plane do not intersect! (there
doesn't seem to be a pattern to which rays in the grid do not
intersect). I realize this is a pretty vague problem statement, but
can anyone think of a reason why the results would be different on
different computers? The computers are both using git master VTK.

Any thoughts of why this would happen or what else I can do to
troubleshoot are appreciated!

David