Here are the screenshots I made for the talk I previously mentioned. They show how the rendering evolves through the choice of shading. The setup consist of a close yellowish punctual light on the up right, and a distant red-ish punctual light on the back left, as well as a dim blue ambient. The objects only differ by the specular exponent, which jumps by a times two factor from one object to the next one, left to right.
![](/blog/wp-content/images/shading/screenshot-diffuse.jpg)
One light, Lambert diffuse only.
![](/blog/wp-content/images/shading/screenshot-diffuse-two-lights.jpg)
Two lights, Lambert diffuse only, with variance shadow map.
![](/blog/wp-content/images/shading/screenshot-diffuse-two-lights-albedo.jpg)
Two lights, Lambert diffuse only, with albedo.
![](/blog/wp-content/images/shading/screenshot-phong.jpg)
Two lights, diffuse and Phong specular. Notice the color on the left.
![](/blog/wp-content/images/shading/screenshot-phong-only.jpg)
One light, Phong specular only. Notice the discontinuity on the left.
![](/blog/wp-content/images/shading/screenshot-blinn-phong.jpg)
Two lights, diffuse and Blinn-Phong specular.
![](/blog/wp-content/images/shading/screenshot-blinn-phong-only.jpg)
One light, Blinn-Phong specular only. Notice the absence of discontinuity.
![](/blog/wp-content/images/shading/screenshot-normalized-phong.jpg)
Two lights, diffuse and normalized Phong specular. Notice the highlight intensity.
![](/blog/wp-content/images/shading/screenshot-normalized-blinn-phong.jpg)
Two lights, diffuse and normalized Blinn-Phong specular.
![](/blog/wp-content/images/shading/screenshot-fresnel-schlick.jpg)
Two lights, diffuse and normalized Blinn-Phong specular, Fresnel term with Schlick
![](/blog/wp-content/images/shading/screenshot-anisotropic.jpg)
Two lights, Heidrich-Seidel anisotropic specular.
Next steps: getting used to the Fresnel version, experimenting with the exponent as a texture lookup, and normalizing the Heidrich-Seibel specular.