Study On Feature Oriented Modeling Of Traditional Artistic Design

The importance of traditional culture heritage protection is growing rapidly world wide, researchers are paying more attention on the modeling of traditional culture heritage. As part of traditional culture heritage, traditional artistic designs are of big values both aesthetically and practically. The modeling process of traditional artistic design includes analyzing the shape as well as artistic characteristics, implementing storing them in computer and showing them to users if necessary. Such modeling research prompots the research how those designs are organized and transform them into methmatical expressions. Potential applications of the resultant models are advertisement, computer animation and entertainment industry. In this dissertationwe present a novel artistic effect named 3D paper-cut, on which 3D mesh models are decorated with 2D paper-cut patterns. We model the paper-cut pattern with feature-oriented modeling paradigm and store them with vector graphics form. We solve the mapping problem that may arise between paper-cut patterns and mesh model during mesh surface editing phase. Specifically we make the following contributions:(1) We present a feature oriented paper-cut pattern modeling pardigm. The paper-cut patterns contain structure with varying form, thus they can not be described in a simple model. We analyse paper-cut pattern features and extract them to comstruct the model with rules of variation. The models are stored in the format of vector graphics for the purpose of reuse.(2) A layer based mesh surface editing method is proposed to simplify the mesh surface editing with different vector graphics, we construct a mapping between vector graphics and local layers which is a sub mesh of original mesh. Layer based mesh surface editing modifies both geometric and topological information of whole mesh. Our method preserve the consistence of topological information during re-meshing phase. Our method can be also used as layer based texture mapping and generating mesh model decorated with both texture and vector graphics. (3) We proposed a hybrid parameterization optimization method utilizing the gradient field manipulation which combines features generated by different parameterization methods. Traditional parameterization methods minimize a single target metric in parametric domain, and get different results. Based on differential theory, we choose the parameterization method for each vertex with less distortion in different methods, and calculate differential coordinates in correspondence parametric domain. Those differential coordinates make a new gradient field which is then used to reconstruct a new mesh model in parametric domain to get the final optimized parameterization result .(4) We present an 3D paper-cut generating system by which we create expressive 3D mesh models with paper-cut effect. These models are build with the layer based mesh surface editing algorithms. Besides we improve a triming algorithm to preview cut out effect in traditional paper cut crafts. We also provide a semiautomatic editing method to accelerate the generation of 3D paper-cut models. The resultant system can be used by artists to make paper-cut animations with ease.