在裝飾紋路當中，雲紋裝飾圖樣扮演著一個十分重要的角色，它是十分常見的一種設計元素，而東方人對於雲紋裝飾圖樣的表現手法有別於西方，以簡單的曲線抽象地呈現雲朵的姿態。非相片寫實電腦繪圖技術(Non-photorealistic Rendering)不同於傳統上的電腦圖學技術，NPR著重於產生各式各樣非傳統光學物理的繪圖效果，最重要的是如何分析各種藝術的結構和技巧，進而加以統整之後，建立系統性的演算法，將其重現於數位空間。本論文便是針對自古所流傳下來的東方雲紋圖樣的設計去做分析，進而發展出一套系統，讓使用者輸入一些簡易的筆畫線條，以此資訊作為雲紋圖樣生成的初始設定，然後自動地產生出具有東方風格雲紋圖樣特徵的結果。 / Cloud patterns are very common design elements used in the oriental decoration, and can well harmonize with other ornament patterns. The expression of oriental cloud patterns uses simple curves to abstract the natural phenomenon. Non-photorealistic computer graphics (NPR) technology focuses on analyzing and integrating the principle of the various arts and skills to establish a systematic method to reproduce the stylization. This thesis tries to analyze the structure of the traditional cloud patterns, and building a system to generate the similar style cloud patterns. The system allows users to sketch some simple strokes lines as an initial setting, and then automatically generate various results with the stylization of the oriental cloud pattern.

本篇論文對於傳統的東方風格雲紋進行分析，歸納其中的生成規則與排列特性，並將雲紋圖樣作簡單的分類，發現雲紋圖樣具有自我相似與遞迴組成的特性，此點特性非常符合原本用於模擬植物生長的L-system，所以我們就針對所蒐集的眾多雲紋圖樣參考資料所分析出的資訊定義了一個適用於立體東方風格雲紋的生成生長規則，以L-system之技術為基礎進行撰寫規則語法，利用所定義結構化之規則循序地在三維空間中動態模擬雲紋的生長與變化。更進一步地，加入具時間序列的參數調整，可以使得雲紋隨著時間軸的變化產生東方風格立體動態雲紋。 / Cloud Pattern is an important and common element in oriental decoration art, it is a challenge to extend the 2D abstract line into 3D objects. In this thesis, we try to induce the pattern generation rule and the feature of oriental cloud by analyzing the ancient oriental cloud pattern. We make classification from the oriental 2D cloud pattern, and discover the pattern is combined with symmetric, self-similar and repetitive features. These characteristic are the core of L-System, which is a suitable framework for plant growth and simulation, so we generate a new rule with specific parameter from the feature of 2D cloud pattern to generate oriental cloud pattern in 3-dimention space, simulating the growth of cloud and variety in structure. Further, we add the time temporal parameter to control the 3D oriental cloud pattern generation process dynamically.

傳統的裝飾紋路，如獸面紋和雲紋，是經過工匠藝術家將其對於自然的變化與鳥獸的形態加以抽象化，藉由這些精妙的花紋傳遞豐富的訊息，形成具有象徵意義的紋路。本論文針對傳統中國雲紋進行分析，發現其保有高度的自我相似性，以此特性為基礎，我們發現到L-system也常被運用於此類特性紋路之創建，本論文以此語法為基礎撰寫生長規則，配合parametric L-system參數化的特性，不但可以讓雲紋達到很好的多樣性，同時配合非相片寫實電腦繪圖技術強化風格效果，讓我們的結果更忠於傳統雲紋，更進一步透過具時間序列的向量場資訊影響L-system之成長，產生具東方風格之動態雲紋。 / Traditional decorative patterns, such as animal mask and cloud patterns, are the art heritage from the abstraction of the changing nature and the shape of animals. These decorative patterns are not only exquisite art, but also meaningful symbolic patterns. In this thesis, we analysis the traditional Chinese cloud patterns, and find out the structure of self-similarity in cloud pattern. In this thesis, we design the growth rules base on the grammar of L-system and the parameterization of parametric L-system. We also combine the stylized line drawing to achieve a good variety of cloud patterns, and our results are faithful to the traditional art. Furthermore, we can generate the dynamic oriental cloud patterns with a time-varying vector field to affect the growth rule.