Richard,
What are you trying to do? We have a product that computes the moments of
inertia and CG for items drawn with 3D faces & surface meshes (It'll work
with AME solids too). It'll also generate & draw x-sec's and compute area
monents of inertia and centroid.
Lots of other stuff too, but I won't deluge with info (at least not
yet<g>).
Ang