In this episode, I discuss lighting in WebGL: Normals.
* Surface color by diffuse reflection = light color * base color of surface * cos A
* Diffuse reflection = reflection differs by light position
* Angle(A) = between the light and surface
* Surface color by ambient reflection = light color * base color of surface
* Ambient reflection = same reflection at any position
* Surface color by diffuse and ambient reflection = surface color by diffuse + surface color by ambient