基於多層次精細度之預先計算輻射轉換

Abstract

在圖學領域中，為了讓及時顯像系統具有全域照度影像品質，預先計 算區域輻射轉換技術在場景中散佈光源樣本，將頂點的顯像方程式轉換為求諧係數加以儲存。由於過程中必須對所有頂點進行計算，為了節省時間與資料量，本論文提出以多層次精細度為基礎的方法，將模型以頂點階層表示，在前置計算階段根據點光源決定裁切線以減少頂點數量。同時運用同樣的資料結構，在系統執行階段根據視點與幾何與光效誤差減少顯示的頂點數量。

To apply global illumination quality image into a real-time rendering system, techniques of pre-computed local radiance transfer sample light source in the scene, and convert the render equation of vertices into spherical harmonics coefficients. All vertices are pre-computed during pre-processing. To lessen the pre-processing time and the data amount, in this thesis, we propose a level-of-detail based method. We convert the model into a vertex hierarchy. We decide a cut depending on the light source sample to reduce the vertices amount during pre-process time. Also we use the same hierarchy to reduce the vertices depending on the view and considering the geometry and lighting error during run-time.