1. Range Profile Synthesis
SAMPL Group Meeting
10 October 2000
By Gerald Dalley

2. Overview Project Goal Ray Tracing Range Profiles and Range Images
Lighting Models
POV-Range

3. Project Goal
“Tanks Under Trees”

4. Ray Tracing -- 2D

5. Ray Tracing -- Math in 2D
Screen
Object Intersected  ds do xo xs

6. Ray Tracing -- 3D

7. Range Profiles -- Theory

8. Range Profiles -- Current Implementation

9. Range Images
Range
Intensity

10. Typical Lighting Model
Ambient
Background light level
Diffuse
Matte surface
Specular
The window on the apple

11. Bidirectional Radiance Distribution Functions (BRDFs)
Surface Normal
Plane of Incidence i i r
Plane of
reflection r
Figure adapted from Advanced Animation and Rendering Techniques, pg. 34

12. BRDFs Cont. i  r Physics-based lighting Example: Wet pavement
Polarized light
Example: Wet pavement
i  r
i and r both small

13. BRDF Simplifications Intensity independent of:
i (no polarization on incoming light)
r (no polarization on outgoing light)
i=r (light source and camera at same point)
I(i, r, i, r)  I()

14. POV-Range What is it? What platforms? Performance?
800x600: min. / 72 frames
8192x8192: hrs. / 1 frame

15. Demo
“POV-Range”
View range image in Matlab

16. Further Information…
Foley, Van Dam, Feiner, Hughes. Computer Graphics: Principles and Practice
Watt, Watt. Advanced Animation and Rendering Techniques
comp.graphics.rendering.raytracing