可有效描繪半透明度材質之快取技術

Abstract

本論文提出一個可有效描繪半透明度材質的快取技術。此快取技術主要靈感來源為 irradiance caching。我們首先採用irradiance caching的基本架構當作我們的基礎。接著提出分割圓(split-disk) 模型決定cache的分布並且轉換dipole diffusion approximation方程式，推導出gradient of subsurface illuminance，最後利用已存好的cache以及gradient of subsurface illuminance來內插圖像。實驗結果顯示，我們只需要很少量的cache便可內插出整張圖像，整體加速約為5~15倍，且內插所產生的視覺誤差幾乎可以忽略。

This thesis presents an efficient rendering technique for translucent materials using caches. The proposed caching scheme, inspired by the irradiance caching method, is integrated into a hierarchical rendering technique for translucent materials. We propose a split-disk model to determine the cache distribution and derive the subsurface illuminance gradient used for interpolation by reformulating the equation of dipole diffusion approximation as a 3D convolution process. Our experiments show that only a few caches are required to interpolate the entire image, while the visual difference is negligible. The speedup could be achieved up to one order of magnitude.