Rendering Caustics on Non-Lambertian Surfaces, Henrik Wann Jensen

Rendering Caustics on Non-Lambertian Surfaces

Henrik Wann Jensen

The Technical University of Denmark

A cardioid caustic on a glossy surface. The receiving surface changes from diffuse (left) to glossy-specular (right).
Note how the photon map can capture the changing appearance of the caustic.


This paper presents a new technique for rendering caustics on non-Lambertian surfaces. The method is based on an extension of the photon map which removes previous restrictions limiting the usage to Lambertian surfaces. We add information about the incoming direction to the photons and this allows us to combine the photon map with arbitrary reflectance functions. Furthermore we introduce balancing of the photon map which not only reduces the memory requirements but also significantly reduces the rendering time. We have used the method to render caustics on surfaces with reflectance functions varying from Lambertian to glossy specular.

Key words: Caustics, Photon Map, Ray Tracing, Rendering


Henrik Wann Jensen: "Rendering Caustics on Non-Lambertian Surfaces". In Proceedings of Graphics Interface '96, pp. 116-121, Toronto 1996.

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