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Henrik Wann Jensen

Computer Graphics Laboratory
Computer Science and Engineering
University of California, San Diego
CSE 4116 (map)
9500 Gilman Drive
La Jolla, CA 92093-0404
(The best way to reach me, note)

Realistic Image Synthesis using Photon Mapping

My area of interest is computer graphics with a focus on realistic image synthesis in particular appearance modeling, global illumination, and rendering natural phenomena.

Translucent marble bust (Diana the Huntress) illuminated from behind Appearance modeling is an active area of research in computer graphics. Understanding the complex and diverse appearance of materials is essential for rendering compelling images. I have worked on subsurface scattering, where light scattering inside translucent objects is taken into consideration. This is important for rendering materials such as marble, milk, and human skin. Recently, we developed a generalized Lorenz-Mie theory for computing the optical properties of translucent materials and scattering media from the basic elements within the materials.

Cornell box with a glass sphere and global illumination Global illumination is another area of research that involves the simulation of all types of light scattering in a model. My PhD research addressed the simulation of global illumination including caustics by introducing the concept of photon mapping. The key features of the photon mapping algorithm are the use of photon tracing and the photon map. The photon map is decoupled from the scene geometry, and it can be used in models with millions of objects and complex materials. Photon mapping is a practical technique capable of simulating color bleeding, caustics, participating media, subsurface scattering, and motion blur. Today, photon mapping is implemented in most high-end rendering software, and it is being used in architectural simulations, computer games, and movies. As an example there was a nice caustics sequence (light focusing through a glass of whisky) in Final Fantasy. I have mostly been concerned with the caustics formed as light is focused through a glass of cognac.

An image of the night sky Rendering natural phenomena is a growing area of research in computer graphics. Examples include a physically based model of the night sky. The goal of this project was to simulate all important visual elements of the night sky (the moon, stars, the atmosphere, the Zodiacal light etc.) including their appearance to the eye (loss of color and blue shift). For this purpose we used multi-spectral rendering combined with an accurate simulation of light scattering in the atmosphere. Another project addresses the simulation and rendering of smoke and fire.

I have been fortunate to work with the following great students: Toshiya Hachisuka (PhD, University of Tokyo), Iman Sadeghi (PhD, Google), Wojciech Jarosch (PhD, Dartmouth University), Craig Donner (PhD, Google), Aleks Palatnik (MSc, Google), Marlena Fecho (MSc, Pixar), Phi Nguyen (MSc, Qualcomm), Jorge Schwarzhaupt (MSc, Weta), Timothy Martin (MSc, startup), Zhe Fu (MSc, Google), Oleg Bisker (MSc, Canfield Scientific), Krystle de Mesa (MSc, Microsoft), Joachim De Deken (MSc, Pixar), Marios Papas (MSc, ETH Zurich), Carlos Caballero (MSc, Papaya Studio), Robert Thomas (MSc, Blizzard Entertainment), Cameron Chrisman (MSc, Blizzard Entertainment), Andrew Watson (MSc), Arash Keshmerian (MSc, Limbic Software), Bin Chen (MSc, Microsoft), John Rapp (MSc, Microsoft), Cyrus Jam (MSc, Industrial Light & Magic)

Our research has been funded by NSF, as well as funding and/or graphics hardware from ATI, CalIT2, NVidia, Photometria, The Sloan Foundation, and Walt Disney Animation Studios. Back in the days we also received an espresso machine from Rhythm+Hues studios (never underestimate the power of good coffee).

Henrik Wann Jensen