1. Caustics Generation by using Photon Mapping Presentation by Michael Kaiser and Christian Finger
Advised by Dr. Marcus Magnor
Light and Color in Nature Seminar,
Max-Planck-Institut für Informatik
2. Motivation Create nice pictures with translucent objects and rendering nice effects on diffuse surfaces.
3. Overview Caustics
4. Light Transport Notation L Lightsource
S Specular reflection
D Diffuse reflection
(k)+ one or more k events
(k)* zero or more of k events
(k)? zero or one k event
(k|k’) a k or k’ event
5. Caustics Caustics are formed when light reflected from or transmitted through one or more specular surfaces strikes a diffuse surface.
In Light transport notation: LS+DE
6. Comparisons Classical Ray Tracing
Does not support Caustics.
Would be qualified for simulating caustics.
But: Probability of going through a series of LS+DE is small.
Bidirectional Path Tracing
Would be also qualified for simulating caustics.
Produces correct pictures, unbiased solution.
Takes too much time for same quality as photon mapping.
7. Comparisons Radiosity
Handles only diffuse reflections LD*E.
Not suitable for rendering caustics.
Handles all kinds of reflections.
It has the following possibilities: L(S|D)*D
Good for Caustics.
8. 2-Pass Algorithm First Pass:
Generating a Global Photon Map and Caustic Map.
9. Photon Maps Global Photon Map
All Photons with property L(S|D)*D are stored.
Only Photons with paths LS+D are directly stored.
Application of a projection map.
10. Photon Mapping Rendering equation is solved by a photon map.
11. Photon Mapping For the rendering part incoming radiance is divided into four parts:
12. Photon Mapping
13. Photon Mapping
17. Outlook Rendering participating media
Additional Volume Photon Map.
Rendering Volume Caustics.
18. Literature Henrik Wann Jensen, “Realistic Image Synthesis Using Photon Mapping”, A.K. Peters, 2001