Last Updated 5-15-98


Normals control how a face and, inevitably, how the 3DO will look. It is a vector (a line that points in a certain direction) scaled to a length of 1.0.

Some people have asked how to calculate them so Here we go: All you have to do to calculate the vector of a face is to take the cross product of two vectors defined by 2 edges of the face. Huh? Well I didn't get it the first time either :-) Ok, you have your face. Now look at a vertex, two lines come off from this vertex. Each of those lines define a vector (represented with arrows):

So we have U and V (our two vectors). But wait, how do you find U and V? Easy: U.x = Vert4.x - Vert0.x, U.x = Vert4.x - Vert0.y, U.y = Vert4.z - Vert0.z. And V = Vert1 - Vert0