Summary: IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS, VOL. 6, NO. 3, JULY­SEPTEMBER 2000, PAGES 253­264 1
Perturbation Methods for Interactive Specular
Reflections
Min Chen, James Arvo
Abstract--- We describe a new approach for interactively
approximating specular reflections in arbitrary curved sur­
faces. The technique is applicable to any smooth implicitly­
defined reflecting surface that is equipped with a ray inter­
section procedure; it is also extremely e#cient as it employs
local perturbations to interpolate point samples analytically.
After ray tracing a sparse set of reflection paths with respect
to a given vantage point and static reflecting surfaces, the al­
gorithm rapidly approximates reflections of arbitrary points
in 3­space by expressing them as perturbations of nearby
points with known reflections. The reflection of each new
point is approximated to second­order accuracy by applying
a closed­form perturbation formula to one or more nearby
reflection paths. This formula is derived from the Taylor ex­
pansion of a reflection path and is based on first and second­
order path derivatives. After preprocessing, the approach

Source: Arvo, Jim - Departments of Information and Computer Science & Electrical and Computer Engineering, University of California, Irvine

Collections: Computer Technologies and Information Sciences