A Study of Adaptive Radiance Estimating Radius of Photon Map

• Main Authors: Mon-Jen Chang, 張孟鈞
• Other Authors: Tsong Wuu Lin
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/08192309423434179807

碩士 === 中原大學 === 資訊工程研究所 === 90 === Photonmap is a global illumination algorithm proposed by Jenson，it uses a energy carrying particle or so called photon and shoot the photons into 3D realistic scene，record the photon hit position and relative information，and use these information to estimate the radiance；because the distribution of photon hit position in photonmap method is not smooth，so the radiance distribution of photonmap is not smooth，too。Furthermore the radiance estimation is the most time consuming procedure of photonmap algorithm，if we can reduce time cost here，we can accelerate the whole photonmap algorithm's computation。 This paper present a new radiance estimating method of photonmap，we compute the radiance coverage of each photon hit，this radiance coverage increasing with the distance of the photon travels in the 3D realistic scene。We also use two parameters Base and Rate to control the increase speed of the radiance coverage in order to fit different scenes。 By the experiment result，improved radiance estimating method no only accelerate the computation of photonmap algorithm but also have the distribution of radiance more smoothly。 Keyword：photonmap，radiance estimation。