1. computer graphics & visualization

2. Raytracing … or where did my performance go? M.G. Chajdas

3. Ray-tracing Name says it all: Trace rays – Lots of rays – And some more Hardware vendors love it!

7. Ray-tracing

10. Goal

12. The rendering equation 5D: BRDF 5D: BRDF 4D: Light Result

13. Rendering equation If you think it‘s complex … It doesn‘t capture: – Phosphoresence – Flurorescence – Intereference – Subsurface scattering

14. Solving the equation Maple? Matlab?

15. Rendering equation What makes it complicated to evaluate? Outgoing light depends on incoming light I.e. it‘s recursive

16. Direct illumination

17. Global illumination … Loss of energy with more bounces!

19. Global illumination Mirror-BRDF:

21. Global illumination Diffuse-BRDF:

23. How to get it fast? Clever sampling Clever intersections

24. Sampling

26. Intersections

27. Classic search problem Trees to the rescue – Space partitioning: Subdivide the space – Object partitioning: Group objects

29. BSP

30. struct Plane { float normal [3]; float dist; }; struct Node { int plane; int children [2]; int boundingBoxMin [3]; int boundingBoxMax [3]; }; struct Leaf { int cluster; int area; int boundingBoxMin [3]; int boundingBoxMax [3]; int firstFaceIndex; int faceCount; int firstBrushIndex; int brushCount; }; Use the source, Luke!

34. BVH

39. Raytracing, recap Raytracing can solve the rendering equation – It can simulate all light transport paths Requires lots of rays – Sample the important directions only, so less rays are wasted – Build acceleration structures so each individual ray is cheap

40. Raytracing, limitations