陳炳宇臺灣大學：資訊網路與多媒體研究所喻至瑋Yu, Chih-WeiChih-WeiYu2007-11-272018-07-052007-11-272018-07-052006http://ntur.lib.ntu.edu.tw//handle/246246/58434在本篇論文中，我們主要的目標就是改善傳統三維繪圖引擎的運算效率，針對其演算法上的瓶頸做修正。我們針對傳統三維繪圖引擎的每個流程階段，提出新的演算法來對運算效率或是繪圖品質做改進。 幾個主要且創新的演算法包括了：1．可視度偵測演算法，大量的減少了z-buffer所需要用的讀取與寫入的運算，同時也減少了繪圖引擎中所需要做的三角形頂點的位置轉換；2•一個新的z-buffer架構，可以減少一半的清除buffer運算；一個新的計算三維模型光影的流程，效果能夠逼近Phong的效果，但是運算複雜度接近Gouraud。 利用模擬器以及手持裝置的測試，整體的運算效率在經過這些演算法的改進之後，有了大幅度的提升。The limited display resolution,small amount of memory, slow memory access rate and narrow bus bandwidth are critical issues that make the rendering performance and quality undesirable. This thesis will mainly focus on improving the performance bottleneck of the traditional graphics pipeline. In addition, in each stage, we present some new algorithms to either speedup the rendering performance or the rendering quality. There are some key innovations included in this thesis : I) The cone-based visibility-test algorithm, which reduces a signi‾cant amount of read/write operations on Z-buffer, and diminishes the number of vertex transformation; II) The view-flipping Z-buffer scheme that avoids half of z-buffer clear operation; III) a lighting system with rendering quality closes to Phong Shading while the computation cost is almost the same as Gauroud Shading. The performance comparisons on software simulator and real devices show that these innovations greatly improve the rendering capabilities on the mobile devices.1 Introduction 6 1.1 Overview 6 1.2 Motivation 7 1.3 Thesis Organization 7 2 Previous Work 8 2.1 Visibility-Test Algorithms 8 2.1.1 Z-Buffer Algorithm 8 2.1.2 Scan-Line Algorithm 11 2.1.3 Visible-Surface Ray Tracing Algorithm 12 2.1.4 List Priority Algorithm 13 2.1.5 Area Subdivision Algorithm 14 2.2 Shading Models for Polygons 16 2.2.1 Gouraud Shading 16 2.2.2 Phong Shading 16 2.3 Silhouette Clipping 17 3 Improved Visibility-Test Algorithm 19 3.1 Cone-Based Visibility-Test Algorithm 19 3.1.1 Hierarchical Visibility-Cones Construction 19 3.1.2 Runtime Algorithm 22 3.1.3 Discussion 25 4 Other Improvement to the Graphics Pipeline 26 4.1 Index Array Acceleration 26 4.2 Hierarchical Early Culling 28 4.3 Modified Shading Model 28 4.3.1 Lighting-Triangle Detection 29 4.3.2 Adaptive Lighting Sampling 30 4.3.3 Pre-computed Shininess Cosine Map 31 4.4 View-Flipping Z-Buffer 32 4.5 Integer Z-Buffer 34 4.6 Jumping Index Rasterization 36 5 Result 37 6 Conclusions and Future Work 41 6.1 Conclusions 41 6.2 Future Work 41 A Alternated Visibility-Test Algorithms 44 B Different Rasterization Directions 46553701 bytesapplication/pdfen-US三維繪圖引擎手持裝置可視度偵測3D graphics enginemobile devicevisibility-testthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/58434/1/ntu-95-R93944004-1.pdf