Game Development Reference
In-Depth Information
Let's now summarize the steps:
1.
Compute a normal, N, for each vertex of the polygon.
2.
From the bilinear interpolation, compute a normal, N, for each pixel.
(This must be renormalized each time.)
3.
From N, compute an intensity, I, for each pixel of the polygon.
Differentiating the shading models
The difference in the output of the shading algorithms is shown in the following
diagram. The Gouraud Lambert shaders do not have any specular highlight but
Gouraud Blinn-Phong uses specular color. Also, note that the object features are
more distinct around the edges in Phong Blinn-Phong shaders:
