1. Lighting and Shadows CSIS 5838: Graphics and Animation for Gaming

2. “Directional” Lamp Type Point source at “infinite” distance (like sun) Shadows based on orthographic projection – All rays essentially parallel at that distance

3. “Point Source” Lamp Type Intensity falls off with distance d – K = 1/ad 2 Shadows based on perspective projection – “Elongated”

4. “Spot” Lamp Type Illuminates elliptical area in direction of lamp – Centered in direction ϴ of lamp – Out to some maximum angle d Illumination decreases with distance from center – Proportional to cos(ϴ/d) ϴ d -d

5. “Skybox” Light Source Light from “all directions” (ambient light) – Represents light reflected from other surfaces – No shadows

6. “Skybox” Light Source Often combined with sun for “outdoor lighting” Different spectrum: – Sun: yellow (1.0, 0.95, 0.5) – Hemisphere: “sky blue” (0.8, 0.9, 1.0) Less intensity than sun (around 0.2)

7. Movie Lighting 3-point lighting – Key light: Simulates main illumination in scene Sun, overhead lamp, etc. Only source that casts shadows – Fill light: Prevents self-shadowing In front of subject, but on other side of camera Much less intense than key light – Back light: Insures entire body of subject illuminated Behind subject, less intense 4-point lighting: Adds source to illuminate background

8. Move Lighting © MovingImageEducation.org