在廣域照明領域中，熱輻射成像法能模擬虛擬場景中複雜的能量傳遞過程而產生相當逼真的影像。然而，其高成本的計算量必須花費許久的時間才能繪製出成像結果，因此無法適用於強調即時性與互動性的應用上。在本篇論文中，我們分別提出三種方法來加速熱輻射成像法的計算時間及成像回應時間，以提昇動態場景的計算效能速度。
在前兩種方法中，我們針對熱輻射成像法中最耗時的鏈結可見度計算步驟及熱輻射成像法的計算流程作為改進目標。第一個方法中我們利用空間分割的方式，配合過去提出的階層式可視度測試(Hierarchical Visibility Testing，H.V.T.)演算法，將判斷所需重算可見度鏈結的計算量減到最低，以減少鏈結可見度的計算回應時間。而第二個方法則是將動態熱輻射成像法加上色調重製(Tone-Reproduction)機制，以降低鏈結(link)細切的數量，並利用能量發射之近似解法(Shooting method) 以達到在單位時間能顯示固定畫框數的計算方式。

此外在複雜的場景中，熱輻射成像法產生的綴片數目相當龐大，可能需要極為昂貴的硬體上才能達到即時遊走的效果，但這些計算卻是由大片的綴片(patch)細切產生，我們提出的第三個方法是將熱輻射成像法計算過程中使用的綴片結構改為材質貼圖的mip-map結構，如此不但不會增加計算所需的時間，同時能加快成像速度，這個方法尤其在動態熱輻射成像法計算(dynamic scene radiosity computation)這種對時間斤斤計較的計算上更顯重要。

本研究除了學理的推導外，並經實例驗證上述三種方法不但可行，且明顯地改善動態場景的成像速度。

In the field of global illumination, the radiosity method has been used to produce some of the most realistic image. However, the cost of its computation time is too much so that it’s not applicable to dynamic environments, that is, virtual scene whose objects are subject to be modified interactively. In this thesis, we propose three approaches to accelerate the computation of traditional radiosity method for dynamic scene.
The most time consuming stage of traditional hierarchy radiosity is visibility testing. In our first approach, we estimate the difference of energy transferred from the links after the scene modified. By ignoring insignificant links, the numbers of links’ visibility testing can be greatly reduced. In the second approach, we propose visibility buffer data structure to approximate link visibility. The basic notion of visibility buffer is to store the visibility distribution of each region in the whole scene. Then, link’s visibility can approximated rapidly by querying it’s associated visibility buffers.

In our third approach, we propose ray buffer data structure extended from visibility buffer to deal with complex scene radiosity which always contains huge numbers of links. The ray buffer data structure stores not only visibility but also energy distribution. Through these information and appropriate energy transfer methods, energy can be redistributed rapidly after dynamic objects are modified which is irrelevant to the amount of links.

Finally, some empirical tests are given to show that our proposed approaches are not only feasible but also achieve interactive frame rate.

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