摘要
基于分割—归并思想将线路三维实体分为现状景物实体和虚拟景物实体,分别研究各子实体的三维造型方法,并应用约束Delaunay三角化理论研制拼合算法,实现将各子实体快速拼合成三维整体模型。在此基础上,提出并实现铁路线路三维模型的视相关简化算法,该算法首先应用累进网格技术构建出网格顶点的层次结构,然后依据视锥截取,背面剔除和屏幕投影误差三个视相关简化准则,从层次结构中实时计算出当前视相关简化网格,最后应用真实感图形绘制技术实现铁路线路三维场景的实时交互式仿真。实践证明,该技术可实时生成具有高度真实感的铁路线路三维场景并可通过鼠标或键盘操控浏览路径,从而实现设计成果与设计过程的可视化。
According to the thought of dividing and converging,the railway alignment 3D design is divided into the actual scene and virtual scene first.Then the 3D modeling method of each subentity is worked out respectively.Then use the constrained Delaunay triangulation theory to develop the converging algorithm,thus we can quickly assemble the various subentities into a whole 3D model.Based on the 3D model,the paper puts forward and realizes the video related simplification algorithm of the 3D railway alignment model.The algorithm first uses the technology of progressive mesh to create a hierarchy structure of mesh vertex.Then,it extracts the current viewdependent meshes realtime from the hierarchy according to such three viewdependent simplification criteria as viewfrustum culling,backface culling and screenspace projection error threshold.Finally,the realtime interactive simulation of railway route 3D scene is realized with the technology of realimage mapping.Practice proves that the whole technology stated in this paper could not only create highly realtime railway route 3D scene but also control the browsing path with a mouse or keyboard.So the visualization of both design progress and the design result is realized.
作者
蒲浩
宋占峰
詹振炎
PU Hao;SONG Zhan-feng;ZHAN Zhen-yan(School of Civil Engineering and Structure,Central South University,Changsha Hunan 410075,China;State-assigned Key Lab of Information Engineering for Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan Hubei 430079,China)
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2003年第5期56-60,共5页
China Railway Science
基金
铁道部科技发展计划基金项目(97G23-F)
关键词
线路设计
三维可视化
实时显示
三维建模
仿真
Railway alignment design
3D visualization
Real-time display
3D modeling
Emulation
