顾及角度误差的三维建筑模型边折叠简化算法

A Simplification Algorithm for Edge Collapse of 3D Building Model Considering Angle Error

随着城市三维场景应用日益增多,海量的三维建筑模型数据给计算机的存储、显示、传输和实时渲染带来了巨大压力,在保证Web 3D展示质量的前提下,有条件地对三维模型进行适度简化,降低复杂模型计算复杂度的有效途径。针对三维建筑模型简化至低分辨率时模型表面细节特征丢失、网格质量降低导致的视觉退化等问题,提出了一种顾及角度误差的三维建筑网格模型边折叠简化算法。该算法在选取收缩边时加入了顶点约束条件,并对生成新面片的旋转方向进行了角度误差控制,提高了模型特征区域顶点的误差度量。研究结果表明,该算法在保留场景中建筑模型的几何特征的前提下,有效地减少了系统绘制的图元数目,适用于渲染大规模三维城市场景。

Objectives:With the increasing application of urban three-dimensional scenes,the huge amount of three-dimensional building model data has brought tremendous pressure to the storage,display,trans-mission and real-time rendering of the computer.On the premise of ensuring the quality of Web 3 D display,moderately simplifying of the three-dimensional model is an effective way to relieve the pressure on computer.Methods:To reduce the visual degradation caused by the loss of detail features and the degradation of mesh quality when the three-dimensional building models are simplified to a lower resolution,a simplification al-gorithm for three-dimensional building mesh model was proposed based on angle error in this article.Results:The vertex constraint was considered in the selection of contractible edges,and the rotation direction of new faces was controlled based on angle error,thereby improving the error metrics of vertices in the fea-ture region of the model.Conclusions:The experimental results show that the proposed algorithm can ef-fectively preserve the geometric features of the building model and reduce the number of elements drawn by the system with acceleration strategies such as in-core and out-of-core exchange,view frustum culling and occlusion culling.