I'm trying to use c_intersect() for determining whether a ray intersects a bounding box.
I didn't have any luck with it, though.

This might by due to me not quite understanding a term in the function's description in the manual: Namely, I'm not sure how to interpret the term "ray distance vector".
But I don't want to rule out the possibility that there might be other reasons why it doesn't work.

I've posted a topic about this on the programming forums: http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=350764#Post350764

Perhaps you could have a look?