隨著電腦動畫技術的進步與普及，以電腦合成出的影像已無所不在，尤其在電影或遊戲工業上的運用，提供繪畫般的超現實空間和擬真世界的影像是同等重要。就像電影美夢成真(What Dreams May Come)的場景中，男主角由現實空間一腳踏入繪畫中如夢似幻的世界帶給觀眾的震撼，或是電視遊樂器上的Legend of Zelda: The Wind Waker以卡通色調呈現出活靈活現的幻想風格，種種技術將不可能化為可能，帶領觀眾與玩家走入另一個世界。

本論文描述一種在點取樣表面上展現非相片寫實顯像風格的架構，針對不同的繪畫風格，選擇相對應的繪圖法則和基本繪圖元素，將三維空間的物體表面產生即時互動的影像。在繪圖的過程中，主要分為何處要下筆和畫出哪一種筆觸這兩大步驟。首先將點取樣表面以階層式樹狀表示，依所需要的筆觸大小和明暗遠近為基準，在階層式樹狀架構中遊走，選出抽象化多層次的候選顯示節點，再依照曲面變化以及色彩差異度，改變顯示節點的分佈密度特性，以此做為下筆的位置。再整理繪畫中的相關技法，應用於繪畫、影線法、半色調以及中國水墨畫等四種技巧上，將形形色色的筆觸繪製其中，呈現多樣化的非相片寫實風格。

This paper describes an interactive Non-Photorealistic Rendering system for point-sampled geometry. This system generates images with various painting style by choosing appropriate rules and stroke patterns.

There are two main components during the painting process. One is where to draw strokes; the other is what stroke to paint.

For a given 3D model, we build a hierarchy presentation of
points. Using an abstract algorithm to traverse the hierarchy architecture to find multi-layers display nodes from coarse to fine based on the multiple-sized brush strokes. Besides, we can apply various distribution density properties as the painting rules, finding candidate display nodes to draw stokes.

Then, we formulate the techniques in painting, hatching, half-toning, and Chinese painting styles, and use various stroke patterns to represent each styled images.

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