基于特征保持的半自动化动态网格简化方法

Semi-automated and dynamic mesh simplification algorithm based on feature preserving

传统的网格简化方法都是按照某种简化算法,通过对模型参数的计算来决定简化的序列和结果,无法进行人为的干预。而在很多情况下,对于某些模型,用户干预可以很大程度地提高简化效果。基于半边折叠和二次误差度量算法,创新性地提出一种半自动化的网格简化方法。简化系统提供自动误差修正和用户误差修正两种误差修正途径,不仅对已有的简化算法进行了改进,而且还提供了一个友好的用户交互平台,通过用户对简化误差的修正来达到用户期望的简化效果。使用动态半边树状层次结构满足了实时仿真的需求,该方法可不绑定特定算法,适用于各种模型简化算法。最后通过对不同类型模型的对比实验,发现与传统的特征保持的网格简化算法相比,使用改进的自动误差修正算法可以很大程度地提高较规则模型的简化质量;而对于构造复杂的模型,通过用户误差修正算法,在优化的基础上结合用户的意愿,对模型指定的特征区域可以完好地保留,很大程度地提高了简化后的外观特征。

In the traditional mesh simplification algorithm, the sequence and the result of the simplification are always deter- mined by the calculation of the model＇ s parameters according to the algorithm, and can＇ t be changed by human. However, the simplification results may be greatly improved by the user＇ s intervention in many cases for some models. This paper presented a semi-automated mesh simplification algorithm based on half-edge collapse and QEM algorithm, to allow displaying the user＇s interest field in high-resolution. It provided automatic error correction and user-controlled error correction, not only improved the result of the simplification, but also provided a user-friendly interactive platform to correct the error according to the user＇ s desire. This paper also applied the dynamic hierarchical structure to store the simplification information for real-time applica- tions, and it could be added in to different algorithms as the different types of the model. Comparative experiments on different types of models show that, the automatic error correction system does better than the regular simplification algorithm on the reg- ular shape models, while the user-controlled error correction system performs better on the irregular shape models. The quality of simplified model has been improved.