Vertex Normal at Each Vertex:
Find the Vertex Normal at Each Vertex
If we stick simply to gray-scale values, the intensity of light at point P (Ip) can be calculated thus :
Is1 = Ic - (Ic - Ia). (y c - y scan)/ yc - ya
Is2 = Ic - (Ic - Ib). (y c - y scan)/ yc - yb
By performing 3 separate calculations, one for red, one for green and one for blue, a complete colour value can be achieved.