Combining Equations 1, 2 and 3,
we obtain Equation 5.

Expanding this into the individual components, and using the definition of vector
cross-product, we obtain the three Equations 6 to 8.

In order to normalise these values, we find the scalar value , using
the values for , and found in Equations
6 to 8.

The values , and given in Equations 10 to 12 are now the , and coordinates of the normalised surface normal to the triangle with vertices , and .

2000-08-22