基于非流形几何与特征树的异质材料实体可视化方法  

Heterogeneous Object Visualization Based on Non-manifold and Feature Tree Representations

作　　者：寇欣宇[1,2] 王以忠[1] 彭一准[1] 

机构地区：[1]天津科技大学电子信息与自动化学院,天津300222 [2]香港大学机械系,中国香港

出　　处：《计算机辅助设计与图形学学报》2008年第4期532-539,共8页Journal of Computer-Aided Design & Computer Graphics

摘　　要：提出一种异质材料实体可视化的方法.采用边界曲面细分技术减小材料分布的突变视觉效应;在不损失渲染质量的前提下,采用自适应曲面细分和冗余曲面滤除方法解决异质实体可视化效率差、难以实时显示的问题.给出了详细的异质实体边界网格生成算法,以显示异质实体的外部几何信息及其内部材料组分的三维分布.该算法采用基于特征树的曲面网格自适应细分策略,通过对异质实体特征树的拓扑结构分析来判定待渲染曲面的材料分布特性,仅对确实需要细分的曲面进行额外的网格细分,有效地减小了实体渲染中所需的计算量;利用非流形异质实体的表征方法,采用冗余曲面滤除方法直接滤除非相关的边界曲面,以满足实时可视化的要求.该方法已用于异质实体建模软件CAD4D中,实验结果表明,其可有效地实现异质实体的实时可视化显示.A novel heterogeneous object visualization approach is presented. Boundary surface sub-faceting is proposed to eliminate the abrupt material transition effects. Adaptive boundary sub-faceting and redundant face removal are further applied to speed up the visualization process. The boundary mesh generation algorithm is provided to render the external geometries as well as the internal material heterogeneities. The underlying ideas of the proposed approach include： 1 ） Using a feature tree based surface tessellation strategy, the material distributions of the boundary surfaces are first evaluated by means of a topological analysis on the heterogeneous feature tree structures; and additional surface sub-faceting is only applied where necessary. 2） Based on the non-manifold heterogeneous cellular representation, the redundant candidate surfaces are directly removed to cater for real-time visualization requirements. The proposed visualization scheme has been successfully implemented and tested in our heterogeneous CAD modeler （CAD4D）, and results show that the proposed approach can generate high quality renderings at interactive rates.

关 键 词：异质实体 可视化 非流形几何 特征树表征 渲染保真度 

分 类 号：TP391.72[自动化与计算机技术—计算机应用技术]