以L-system為基礎的3D植物性裝飾造型產生系統

在3D特效電影-阿凡達中的森林場景係由一個3D CAD工具軟體-SpeedTree所建造而成，這類軟體是為了給創建和渲染植物的遊戲使用所開發的軟體，並提供使用者一個1000種植物骨架模型的資料庫，除了SpeedTree之外，有好幾種相似的開發工具軟體去模擬3D植物，例如：Xfrog，所有的這些軟體都可以幫助使用者去建造植物的3D擬真圖像。在本篇論文中，我們開發了一個不同的系統，目的是生成 3D非擬真圖像的植物，我們的系統提供使用者以互動方式去產生L系統的L文法和創建3D裝飾性植物骨架的功能。 L系統是電腦圖學領域中模擬植物的主流方法之一，因為其自我擴展的結構是非常適合創建複雜的器官結構元件，然而，使用者很難在沒有合適的工具支援下從無到有去創建。因此，在我們的系統中，開發及整合三個核心組織來支援使用者在不同階段的創建，包括建構植物的3D骨架模組並自動轉換成L文法，Leaf-CAD系統則以互動式設計樹葉的紋理和形狀，及一個圖形引擎RSim-Eco，負責載入L文法並模擬裝飾性的3D植物圖像。

關鍵字

參數化L-System ； 3D 植物模型；電腦圖學；裝飾性藝術

並列摘要

The forest scenes in the amazing 3D movie, Avatar, are built from a 3D CAD toolkit called SpeedTree. This software is developed for creating and rendering vegetation in games, and provides users a database with about 1000 plant surface-models in it. In addition to the SpeedTree, there are several similar toolkits developed for modeling 3D plants, such as Xfrog. All these software can help users create 3D Photo-realistic images of plants. In this paper, we develop a different system which aims to generate 3D Non Photo-realistic images of plants. Our system provides users capabilities to interactively build the L-Grammar of L-System and create 3D ornamental models of plants. L-System is one of the mainstream approaches used for modeling plants in the field of Computer Graphics, because its self-expandable structure is very suitable for creating complicated components of organic structure. However, it is very difficult for users to go through the process of growing out of nothing without appropriate tools. Therefore, our system develops and integrates three core components to support users in different stages of creation, including a module for constructing plant’s 3D skeletons and converting them into the format of L-Grammar automatically, a Leaf-CAD tool for interactively designing the textures and shapes of leaves, and a graphics engine, RSim-Eco, for loading L-Grammar and rendering 3D ornamental plant images.

並列關鍵字

Parametric Lindenmayer system ； 3D Plant simulation ； Computer Graphics ； Decorative pattern

參考文獻

[1] Wojciech Pałubicki, Kipp Horel, Steven Longay, Adam Runions, Brendan Lane, Przemyslaw Prusinkiewicz, Radom’ır Mˇech, “Self-organizing tree models for image synthesis”, ACM Transactions on Graphics, Vol. 28, No. 3, Article 58, August 2009.