Local Illumination Pictures

1. Local Illumination Pictures Gerda Kamberova

2. Lightinginteraction between objects’ materials and geometry, and the light sources Shadingthe process of performing the lighting computations and determining pixels’ color from them. Three basic models discussed Flat Gouraud Phong Programming OpenGL Updating the hierarchical scene model Summary: Intro to Lighting and Shading Gerda Kamberova

3. Lambert’s law Ip(L.N) Ip N L P It does not matter where the viewer is, he sees reflected light in the mount of Ip(L.N) Gerda Kamberova

4. Specular reflection N L R Ip V P Light reflected in direction of V = Ip(R.V) Each time viewer changes position must be recomputed  Gerda Kamberova

5. Specular reflection N L R Ip a a -b b P R = -b+a = -(L-a)+a = -(L-(L.N)N)+(L.N)N = 2(L.N)N – L If the relative position of light and object changes, must be recomputed Gerda Kamberova

6. Using the half-way vector to speed up computation N H L R Ip V P H=(L+V)/|L+V| 2(H.N) approximates (R.V), H is easier to compute than R Gerda Kamberova