臺灣博碩士論文加值系統

浮雕貼圖技術提供一個新的方法利用一張高度資訊圖讓一個簡單的模型可以描繪出複雜的物件的模樣，然而，因為效能並不夠快，所以浮雕貼圖目前還不能廣泛的使用在各種應用程式，而且在高度資訊圖高低差很大的時候，浮雕貼圖會產生出一些描繪的瑕疵。在這篇論文中，我們對浮雕貼圖提出一個新的演算法，我們提出的演算法利用一張極大極小材質來大量的減少算交點時候的搜尋空間，我們利用前處理產生這張極大極小材質，因此我們可以大幅度的減少搜尋交點所需要的次數，最後就可以同時改善效能以及視覺效果。

實驗結果指出，我們提出的方法同時在效能以及視覺效果上贏過其他的浮雕貼圖技術。

Relief texture mapping is a novel technique that creates an illusion of complex
geometric objects on a simple polygonal surface using a height-field texture.
However, relief texture mapping method cannot be used in applications such
as games because the performance is not fast enough. It also has artifacts
if the height-field is with high-frequency. In this thesis, we proposed a new
algorithm for relief texture mapping. This algorithm greatly reduces search
area when finding the intersection between rays and height-field by exploiting
the min-max information. In the preprocessing step, we create minmax texture
to store min and max-min depth values that intersected by the rays passing
through the texel. Thus we can reduce the search steps and then improve the
performance and the visual quality.
As the experimental results show, we proposed method have the better
results for both performance and visual quality than other RTM algorithms.

1 Introduction 1
2 Related Work 5
3 Proposed Method 13
4 Minmax Texture Creation 19
5 Finding Intersection 25
5.1 Why not using adaptive steps? . . . . . . . . . . . . . . . . . . . 27
6 Experimental Results and Evaluation 29
6.1 Quality and Speed Comparisons . . . . . . . . . . . . . . . . . . 29
6.2 Related Work Comparisons . . . . . . . . . . . . . . . . . . . . 36
6.3 Discussion on parameter . . . . . . . . . . . . . . . . . . . . . 38
6.4 The preprocess time . . . . . . . . . . . . . . . . . . . . . . . . 39
6.5 Adaptive steps vs. static steps . . . . . . . . . . . . . . . . . . . 41
7 Conclusions and Future Works 43
7.1 Encoded the minmax texture to a normal map . . . . . . . . . . 43
7.2 Automatic parameter computation for different meshes . . . . 44
7.3 Improving the preprocessing time . . . . . . . . . . . . . . . . . 44
Bibliography 45
A Shader Code in HLSL 49

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