Easy modeling of realistic trees from freehand sketches  

作　　者：Jia LIU Zhiguo JIANG Hongjun LI Xiaopeng ZHANG 

机构地区：[1]Image Processing Center,School of Astronautics,Beihang University,Beijing 100191,China [2]NLPR-LIAMA,Institute of Automation,Chinese Academy of Sciences,Beijing 100190,China [3]College of Science,Beijing Forestry University,Beijing 100083,China

出　　处：《Frontiers of Computer Science》2012年第6期756-768,共13页中国计算机科学前沿（英文版）

基　　金：Acknowledgements This work was supported in part by the National Natural Science Foundation of China （Grant Nos. 60970093, 60902078, 6117210, and 61072151）; by Natural Science Foundation of Beijing （4112061）, and by the Scientific Research Foundation for the Returned Overseas Chinese Scholars of State Education Ministry of China.

摘　　要：Creating realistic 3D tree models in a convenient way is a challenge in game design and movie making due to diversification and occlusion of tree structures. Current sketch-based and imagebased approaches for fast tree modeling have limitations in effect and speed, and they generally include complex parameter adjustment, which brings difficulties to novices. In this paper, we present a simple method for quickly generating various 3D tree models from freehand sketches without parameter adjustment. On two input images, the user draws strokes representing the main branches and crown silhouettes of a tree. The system automatically produces a 3D tree at high speed. First, two 2D skeletons are built from strokes, and a 3D tree structure resembling the input sketches is built by branch retrieval from the 2D skeletons. Small branches are generated within the sketched 2D crown silhouettes based on self-similarity and angle restriction. This system is demonstrated on a variety of examples. It maintains the main features of a tree： the main branch structure and crown shape, and can be used as a convenient tool for tree simulation and design.Creating realistic 3D tree models in a convenient way is a challenge in game design and movie making due to diversification and occlusion of tree structures. Current sketch-based and imagebased approaches for fast tree modeling have limitations in effect and speed, and they generally include complex parameter adjustment, which brings difficulties to novices. In this paper, we present a simple method for quickly generating various 3D tree models from freehand sketches without parameter adjustment. On two input images, the user draws strokes representing the main branches and crown silhouettes of a tree. The system automatically produces a 3D tree at high speed. First, two 2D skeletons are built from strokes, and a 3D tree structure resembling the input sketches is built by branch retrieval from the 2D skeletons. Small branches are generated within the sketched 2D crown silhouettes based on self-similarity and angle restriction. This system is demonstrated on a variety of examples. It maintains the main features of a tree： the main branch structure and crown shape, and can be used as a convenient tool for tree simulation and design.

关 键 词：virtual reality tree modeling SKETCH 

分 类 号：TP391.72[自动化与计算机技术—计算机应用技术] S718.43[自动化与计算机技术—计算机科学与技术]