[ LiB ] |
Diffuse light reflecting across a surface is easily simulated using photon mapping because the photon map is constructed only by diffuse interactions. Figures 14.1 through 14.3 show some diffuse interactions that were rendered using photon mapping. Figure 14.1 shows an example of diffuse interaction and indirect illumination on a desk model with a pyramid-looking object on top of the desk. The scene includes one light source that casts a shadow for the pyramid object.
Figure 14.2 shows a scene with two lights that cast two shadows per object. If you look closely, you actually see the penumbra in the shadows.
Figure 14.3 shows diffuse interaction and indirect illumination on a textured desk model with a sphere, cup, and box. This scene has two lights that cast multiple shadows reflected on the desk from the three objects.
Triangles require a relatively low number of photons to look realistic, whereas spheres, due to their curved nature, require a minimum of 10,000 photons. Figure 14.4 shows a comparison of a photon and a sphere.
[ LiB ] |