Thread Subject: best way to do this?

Hi all,

Suppose I have a closed surface which is represented as a triangular mesh (all triangles have an outward pointing surface normal), how do I efficiently test whether a given point is inside or outside it? For example, the closes surface can be generated from an isosurface. Is there an existing Matlab code to achieve this? Please note that in general I have a lot of points to test, so efficiency is important.

Thanks a lot.