surface normal calculations

As long as all the vertices are in the same order (CW or CCW, it doesn't matter which), then this is easy.

If you have clockwise A, B, C, then (A-B) x (C-B) will be outward. If CCW, (C-B) x (A-B) will be outward.

Remember the right hand rule: take your right hand and extend the fingers forward with your thumb 90 degrees to them (on the same plane as your palm), almost like you are about to give a high five. If your thumb is in the direction of u and your fingers are in the direction of v, then your palm is in the direction of u x v.

thx!
looks like i need to recheck my vertices again then

just a small hack to avoid rechecking vertices,if your object is centered
on a point called Center and the surface is convex, you can simply do a dot product between the normal you calculated N, and V=position_of_vertex-Center :
if (V dot N)>0 then Normal is going out of the object, otherwise normal is going in.
However this won't work in most cases.
snoozeman