1. Ray Tracing CS 351-50 Nov. 19, 2003

2. Turner Whitted

4. No Bounces

5. One Bounce

6. Two Bounces

8. Reflection Ray R = ( -I. N) N + I + (-I. N) N = I - 2 (I. N) N N  -I n R  ( -I. N) N -I - (-I. N) N R ( -I. N) N -I + (-I. N) N I = incident ray = -d N = normal vector R = reflected ray

9. Adding an object: transparency

11. Refraction n sin  = n t sin 

12. Index of Refraction > 1

13. Index of Refraction < 1 total internal reflection

15. Algorithm Trace (ray){ For each object in scene intersect (ray, object) If no intersections return background_color For each light for each object in scene intersect(shadowRay, object) Accumulate local illumination Trace (ReflectionRay) Trace (TransmissionRay) Accumulate global illumination Return illumination }

17. Sampling

18. Ray Tracing Demos http://www.siggraph.org/education/materials/HyperGraph/raytrace/rt_java/raytrace.html http://www.cs.berkeley.edu/~efros/java/tracer/tracer.html

19. Sampling Demo

20. Texture & Materials

22. Links http://www.acm.org/tog/GraphicsGems/