臺灣博碩士論文加值系統

在中國水墨畫中，山岳的畫法是一個相當重要的部份。在這篇論文中我們提出了一套半自動化的「虛擬景觀導覽生成系統」，此系統能夠將人造衛星所拍攝的數位標高圖(Digital Elevation Model)轉化為具有中國山水畫風格的虛擬景觀，並且可讓使用者在即時的狀態下自由的瀏覽。

這套系統首先會以使用者的的視角自動地找出整個三維模型的輪廓線，這包含了找出模型中每個邊是否輪廓線的判斷，再經由分析Depth-Buffer的內容將不可見的輪廓線剔除，以及連接相近的輪廓線使之成為一完整的筆觸線條。

在自動完成筆觸線條的連接後，我們提供了一個讓使用者能自由創作水墨畫風格的介面。這介面允許使用者調整畫面上可見的筆觸線條的筆法與粗細、陰影位置與高度，以及是否要加上附加物如樹木、草或石頭。除此以外，藉由本身隱藏在地理圖形裡面的幾何資訊，本系統會輔助使用者在輪廓線之間輕易的點畫出內部的陰影線條(Hatching)，而完成一幅3D的山水墨畫。

使用者在這幅山水墨畫中移動瀏覽時，由於視角的改變，將會有許多新的線條產生，本系統會經由簡單的記憶和推理方式，系統程式自動產生新增加的筆觸樣式，讓整個瀏覽過程流暢而且平順。

Mountain drawing is an essential part of Chinese water-ink painting. This thesis developed an interactively rendering technique and a real-time touring procedure for landscapes with water-ink painting styles in which the geometric information of the landscapes were acquired from DEM (Digital Elevation Model) terrain files shot by satellites.

According to the user’s viewing direction, this system automatically finds the silhouettes of the 3D terrain, which includes the detection of the edges, the determination of the edge’s visibility, and the connection of the near edges to form a complete stroke.

After connecting the strokes, this system provides an intelligence interface for users to create stylish painting strokes. Users can adjust the stroke’s texture, the stroke’s thickness, and the stroke’s shadow position and height. They can add some accessories, such as trees, grasses, and small stones, to enhance the stroke’s style as well. Moreover, the system can assist users in painting the inner hatching between the silhouette strokes. The final result is a 3D landscape painting with water-ink styles.

When users observing the 3D painting, there are many new strokes being generated due to the change of the viewing direction. This system can record the styles of the existed strokes and randomly compute the styles for the new strokes. In such the way, smooth touring into the 3D painting is possible.

摘要 i
Abstract ii
誌謝 iii
目錄 iv
圖目錄 v
第一章 導論 1
1.1 研究動機 1
1.2 相關研究 1
第二章 輪廓線的搜尋與連接 7
2.1 輪廓線的分類 7
2.2 輪廓線搜尋演算法 10
2.3 剔除不可見的輪廓線 14
2.4 連接可見的邊線線段 16
第三章 互動式水墨繪畫系統 19
3.1 輪廓筆觸線條的屬性 19
3.2 輪廓之間的筆觸線條 26
3.3 人物與鳥獸繪畫的應用 31
第四章 具水墨畫風的虛擬景觀導覽 34
4.1 背景圖的附加 34
4.2 虛擬景觀的導覽 34
4.3 成果展示 35
第五章 結論及未來方向 39
5.1 結論 39
5.2 未來發展方向 39
參考文獻 41

[1] Tobias Isenberg, Nick Halper, Thomas Strothotte, “Stylizing silhouettes at interactive rates: From Silhouette Edges to silhouette strokes,” Eurographics 2002, vol. 21, no. 3, pp. 249-258

[2]Tobias Isenberg, Bert Freudenberg, Nick Halper, Stefan Schlechtweg, Thomas Strothotte, “A Developer''s Guide to Silhouette Algorithms for Polygonal Models,” IEEE Computer Graphics and Applications, 2003, vol. 23(4), pp. 28-37

[3] Aaron Hertzmann , Denis Zorin, “Illustrating smooth surfaces,” SIGGRAPH 2000, pp. 517-526

[4]Matthew Webb, Emil Praun, Adam Finkelstein, Hughes Hoppe, “Fine Tone Control in Hardware Hatching,” NPAR 2002, p. 53-58

[5]P. Rustagi, “Silhouette Line Display from Shaded Models,” Iris Universe, Fall 1989, pp. 42-44

[6] John Buchanan, Mario Costa Sousa, “The Edge Buffer: A Data Structure for Easy Silhouette Rendering,” NPAR 2000, pp. 39-42

[7] Emil Praun, Hugues Hoppe, Matthew Webb, Adam Finkelstein, “Real-Time Hatching,” SIGGRAPH 2001, pp. 579-584

[8] D. Kirsanov, P. V. Sander, and S. J. Gortler, “Simple silhouettes over complex surfaces,” Eurographics Symposium on Geometry Processing, 2003, pp.102-106

[9] Li-Yi Wei, Marc Levoy, “Fast texture synthesis using tree structured vector quantization,” SIGGRAPH 2000, pp. 479-488

[10]Youetsu SATO, Tadahiro FUJIMOTO, Kazunobu MURAOKA, Norishige CHIBA, “Stroke-Based Suibokuga-Like Rendering for Three-Dimensional Geometric Models - Ten and Shun Touches -,” 芸術科���挼蚺撱x, 2004, vol. 3, no. 4, pp. 224-234


[11]Thomas Luft, Oliver Deussen, “Non-Photorealistic Real-Time Rendering of Characteristic Faces,” Pacific Graphics 2004, pp. 339-347

[12]Robert D. Kalnins, Philip L. Davidson, Lee Markosian, Adam Finkelstein, “Coherent Stylized Silhouette,” SIGGRAPH 2003, pp. 856-861

[13] Michael P. Salisbury, Michael T. Wong, John F. Hughes, and David H. Salesin, "Orientable Textures for Image-Based Pen-and-Ink Illustration," SIGGRAPH 1997, pp. 401-406

[14] Doug DeCarlo, Anthony Santella, “Stylization and Abstraction of Photographs,” SIGGRAPH 2002, pp. 769-776

[15] James Hays, Irfan Essa, “Image and Video Based Painterly Animation,” NPAR 2004, pp. 113-120

[16] Nelson S.-H. Chu, C.-L. Tai, "Real-time Painting with an Expressive Virtual Chinese Brush," IEEE Computer Graphics and Applications, September/October, 2004, Vol. 24, No. 5, pp. 76-85

[17] W. Baxter, V. Scheib, M. Lin, and D. Manocha, "DAB: Interactive Haptic Painting with 3D Virtual Brushes," SIGGRAPH 2001, pp. 461-468