Proposal: The goal of this project is to render the rocky pond above. The ripples on the surface of the water focus sunlight into bright lines on the rock bed. In computer graphics, the rendering of such "caustics" has traditionally been difficult. The recently developed technique of photon maps has been applied successfully to this problem; however, most computer generated images show caustics on flat geometry. The scene above is interesting because of the projection of caustics onto a complex, realistic surface.

Primary Goal

The primary emphasis of the project will be on caustic light effects generated by the focusing of sunlight through the undulating surface of the water. We intend to model the caustic effects with a photon map, as described by Henrik Wann Jensen. The geometry of the water surface will be modelled as waves from various point sources.

Secondary Goals (to be chosen from the following)

To model the rock bed geometry by placement of individual, texture mapped stones. Texture may be applied with a Ken Perlin noise function, as well as bump mapping.

To animate the scene by varying the surface of the water realistically.

To simulate the scattering properties within the water. One technique to do this might be volume rendering using a volume photon map.

To model the reflection from the sky (greater effect towards the horizon). This calculation would take into account the Fresnel effect.

To simulate the slight rainbox effect around caustics due to wavelength dependent refraction.

Task Allocation

The most important aspect of this project is implementing a photon map for simulation of caustics. Ren will implement the casting and storage of photons, and Prashant will render the scene from the stored photon map. After completion of this primary module, we will select individually from the remaining secondary goals outlined above.

References

Wann Jensen, H., A Practical Guide to Global Illumination Using Photon Maps.