Light Source Interpolation for Sparsely Sampled Reflectance Fields


Billy Chen

Stanford University

Hendrik P. A. Lensch

Stanford University


10th International Fall Workshop on Vision, Modeling, and Visualization 2005




In this paper we address the problem of relighting with sparsely sampled reflectance fields. We present a technique that approximates the correct result of relighting from intermediate light source positions. The acquisition of reflectance fields is a time consuming process, and typically the sampling resolution in the light source positions is rather limited. As a consequence, smoothly moving highlights and shadows due to relighting with a moving light source are hard to generate. Using light source interpolation, densely sampled reflectance fields can be simulated, enabling relighting with area light sources and smooth animation of highlights and shadows. Using light source interpolation we can relight with arbitrarily sampled 4D incident light fields from complex or near-by light sources.



Comparison between naive blending (left) and compositing after shadow warping and stenciling (right) half-way between two key frames. While the left image shows cross-fading between two shadows we obtain a single shadow using our pipeline.

Simulation of an area light source. By integrating over 15 interpolated frames (3 of them key frames) we can generate a soft shadow without banding.

Illumination with a 4D incident light field. Using the presented interpolation framework, arbitrary high resolution light fields can be projected into the scene. By projecting the same checkerboard pattern from a small but densely sampled range of positions we simulate a projector with an extremely wide aperture having only a small focus region in the middle of the scene.


Adobe Acrobat PDF (2.25 MB)

Color plate

Adobe Acrobat PDF (1.06 MB)



(uses Windows Media Player 9 codec)

A demonstration of light source interpolation (AVI 2.36 MB)