The railway 3D visual design plays an important role in checking the rail projects and improving the quality of railway design, because the key to implement Railway a 3D visual design is to build a 3D model of railway...The railway 3D visual design plays an important role in checking the rail projects and improving the quality of railway design, because the key to implement Railway a 3D visual design is to build a 3D model of railway line landscape. The study on the methods of building a 3D model of railway line landscape is of important academic significance and practical value. We constructed a 3D digital terrain model with aerial survey Data or manual survey data in the regional railway, utilizing plan, profile, cross section data and bridge, tunnel, railway bed data to create the 3D railway line model and merging the two models to form a 3D model of railway line landscape. Based on analyzing the algorithms of Delaunay triangulation creation in Domestic and abroad, in view of the situation of building DTM and the need of realizing railway 3D visual design, a divide and conquer algorithm of building DTM is presented. The algorithm uses square grids to manage disordered points, to form triangular meshes in grids, DTM can be obtained by merging the triangular meshes so that the work of sorting the disordered points before building DTM is reduced greatly; moreover, the algorithm utilizes sub area to control the vertices of convex hull so that the range can be predefined when searching support points, the workload of searching support points reduced and the speed of merging two triangulations raised. A method for inserting constrained boundaries in DTM based on the study of the generation of constrained Delaunay triangulation is presented. First, we searched for the diagonals not intersecting with the constrained boundaries. Then we used them to cut the influenced area. The method has the advantages of a plain principle and a fast speed. The method of utilizing plan, profile, cross section data and digital terrain model to establish the 3D model of the main construction of railway line and the terrain model is presented. It describes the irregular entity surfaces by cutting them into regular entity surfaces, so that it would be simple and raise for the drawing and display of the entities. The method does not only suit single track railway line but also the double track railway line. Merging terrain 3D model and railway line 3D model to build the 3D model of railway line landscape is the core of implementing railway 3D visual design. The key of merging the two models is to hide the ground where the railway line is to be constructed. The problem is studied and a divide and conquer method is presented. First, generating a regular quadrangular mesh by means of DEM data. Then finding the regions that railway bed is located and cutting the regions into grids. If the boundaries of a grid covers another grid, then delete the grid. If the grid contains the boundaries then forming two triangles using the four vertices of the grid. Finding out the points where the boundaries and the triangles intersect. Inserting the points and the vertices of the boundaries into the existing triangular mesh to form a new triangular mesh. At last deleting the triangles which is located in the boundaries and the ground is hided. Moreover, the problem of merging two railway beds which are interrelated and the terrain surface is solved by using the separate and intersect method and in the segment where the railway vary from a double track railway integral bed to two beds of single track railway or vice versa. Based on the mathematical model, the development of the railway 3D visual design system with object oriented programming is completed. The correctness is proved by using the software to make the 3D landscape model and animation of Xi′an Nanjing railway, Xi′an Yan′an railway and SuiLing ChongQing railway; in the meantime, the practicability and adaptability is discussed.展开更多
为提供一种科学化、规范化的露天矿爆破设计三维可视化技术和方法,对露天矿爆破计算机辅助设计技术和爆破机理进行了深入研究。以AutoCAD为开发平台,采用Visual Studio 2008中的visual C++环境,结合AutoCAD的二次开发工具ObjectARX对三...为提供一种科学化、规范化的露天矿爆破设计三维可视化技术和方法,对露天矿爆破计算机辅助设计技术和爆破机理进行了深入研究。以AutoCAD为开发平台,采用Visual Studio 2008中的visual C++环境,结合AutoCAD的二次开发工具ObjectARX对三维地质模型软件SMCAD进行了再次开发,研究出露天矿爆破设计三维可视化系统应用软件。通过在神宝能源公司一号露天煤矿的应用表明,该软件不仅可以通过多次演示,优化出最佳起爆顺序和爆堆形状,而且具有较强的适应性和扩展性,极大地提高了露天矿企业的爆破管理水平和设计效率,减轻设计人员的劳动强度,为爆破设计方案的有效决策及露天矿台阶爆破三维可视化设计的科学化、规范化提供了依据。展开更多
文中将Web技术与World Wind开源软件结合起来,通过三维建模技术和三维GIS技术开发设计一个具有交互功能的Web三维可视化平台。该平台采用B/S架构,应用空间数据库PostgreSQL储存管理三维数据和二维属性数据,使用Web World Wind软件实现...文中将Web技术与World Wind开源软件结合起来,通过三维建模技术和三维GIS技术开发设计一个具有交互功能的Web三维可视化平台。该平台采用B/S架构,应用空间数据库PostgreSQL储存管理三维数据和二维属性数据,使用Web World Wind软件实现三维数据的显示,开发完成了模型加载、空间量测、模型搜索、属性显示、飞行漫游和二三维联动等功能。利用该平台用户只需使用浏览器就能访问查看场景的三维效果,从而达到三维可视化目的。展开更多
文摘The railway 3D visual design plays an important role in checking the rail projects and improving the quality of railway design, because the key to implement Railway a 3D visual design is to build a 3D model of railway line landscape. The study on the methods of building a 3D model of railway line landscape is of important academic significance and practical value. We constructed a 3D digital terrain model with aerial survey Data or manual survey data in the regional railway, utilizing plan, profile, cross section data and bridge, tunnel, railway bed data to create the 3D railway line model and merging the two models to form a 3D model of railway line landscape. Based on analyzing the algorithms of Delaunay triangulation creation in Domestic and abroad, in view of the situation of building DTM and the need of realizing railway 3D visual design, a divide and conquer algorithm of building DTM is presented. The algorithm uses square grids to manage disordered points, to form triangular meshes in grids, DTM can be obtained by merging the triangular meshes so that the work of sorting the disordered points before building DTM is reduced greatly; moreover, the algorithm utilizes sub area to control the vertices of convex hull so that the range can be predefined when searching support points, the workload of searching support points reduced and the speed of merging two triangulations raised. A method for inserting constrained boundaries in DTM based on the study of the generation of constrained Delaunay triangulation is presented. First, we searched for the diagonals not intersecting with the constrained boundaries. Then we used them to cut the influenced area. The method has the advantages of a plain principle and a fast speed. The method of utilizing plan, profile, cross section data and digital terrain model to establish the 3D model of the main construction of railway line and the terrain model is presented. It describes the irregular entity surfaces by cutting them into regular entity surfaces, so that it would be simple and raise for the drawing and display of the entities. The method does not only suit single track railway line but also the double track railway line. Merging terrain 3D model and railway line 3D model to build the 3D model of railway line landscape is the core of implementing railway 3D visual design. The key of merging the two models is to hide the ground where the railway line is to be constructed. The problem is studied and a divide and conquer method is presented. First, generating a regular quadrangular mesh by means of DEM data. Then finding the regions that railway bed is located and cutting the regions into grids. If the boundaries of a grid covers another grid, then delete the grid. If the grid contains the boundaries then forming two triangles using the four vertices of the grid. Finding out the points where the boundaries and the triangles intersect. Inserting the points and the vertices of the boundaries into the existing triangular mesh to form a new triangular mesh. At last deleting the triangles which is located in the boundaries and the ground is hided. Moreover, the problem of merging two railway beds which are interrelated and the terrain surface is solved by using the separate and intersect method and in the segment where the railway vary from a double track railway integral bed to two beds of single track railway or vice versa. Based on the mathematical model, the development of the railway 3D visual design system with object oriented programming is completed. The correctness is proved by using the software to make the 3D landscape model and animation of Xi′an Nanjing railway, Xi′an Yan′an railway and SuiLing ChongQing railway; in the meantime, the practicability and adaptability is discussed.
文摘为提供一种科学化、规范化的露天矿爆破设计三维可视化技术和方法,对露天矿爆破计算机辅助设计技术和爆破机理进行了深入研究。以AutoCAD为开发平台,采用Visual Studio 2008中的visual C++环境,结合AutoCAD的二次开发工具ObjectARX对三维地质模型软件SMCAD进行了再次开发,研究出露天矿爆破设计三维可视化系统应用软件。通过在神宝能源公司一号露天煤矿的应用表明,该软件不仅可以通过多次演示,优化出最佳起爆顺序和爆堆形状,而且具有较强的适应性和扩展性,极大地提高了露天矿企业的爆破管理水平和设计效率,减轻设计人员的劳动强度,为爆破设计方案的有效决策及露天矿台阶爆破三维可视化设计的科学化、规范化提供了依据。
文摘文中将Web技术与World Wind开源软件结合起来,通过三维建模技术和三维GIS技术开发设计一个具有交互功能的Web三维可视化平台。该平台采用B/S架构,应用空间数据库PostgreSQL储存管理三维数据和二维属性数据,使用Web World Wind软件实现三维数据的显示,开发完成了模型加载、空间量测、模型搜索、属性显示、飞行漫游和二三维联动等功能。利用该平台用户只需使用浏览器就能访问查看场景的三维效果,从而达到三维可视化目的。
