Algorithm for simplifying 3d surface?

Question

I have a set of 3d points that approximate a surface. Each point, however, are subject to some error. Furthermore, the set of points contain a lot more points than is actually n

Answer 1

I'd approach this by looking for vertices (points) that contribute little to the curvature of the surface. Find all the sides emerging from each vertex and take the dot products of pairs (?) of them. The points representing very shallow "hills" will subtend huge angles (near 180 degrees) and have small dot products.

Those vertices with the smallest numbers would then be candidates for removal. The vertices around them will then form a plane.

Or something like that.