With the rapid development of photogrammetry,computer vision and three-dimensional(3D)modeling technologies,it is possible to efficiently construct detailed 3D urban models.Accordingly,large corpora of 3D models,such ...With the rapid development of photogrammetry,computer vision and three-dimensional(3D)modeling technologies,it is possible to efficiently construct detailed 3D urban models.Accordingly,large corpora of 3D models,such as the Google 3D Warehouse,are now becoming freely available on the web.How to find the proper 3D urban models is a challenging research issue.In this paper,we join shape descriptors and color descriptors for 3D urban model retrieval.The query objects are localized and segmented automatically from the input images by using a new selective search voting algorithm.Through combining the normalization with the light field descriptor,the Horizontal Light Descriptor is introduced to measure the shape similarity among the normalized urban models.The color descriptors are used to represent the color information of the urban models.The two types of descriptors are joined to search 3D urban models similar to the query objects.Experimental results have shown the effectiveness of our approach.展开更多
将Unity3D技术应用于城市轨道交通培训领域,主要对城市轨道交通线路电子沙盘的建模和控制进行研究。利用Multigen Creator与3ds MAX建立了城市轨道交通线路场景模型,以Unity3D为三维驱动引擎,Visual Studio C#2015为脚本编译器,实现了...将Unity3D技术应用于城市轨道交通培训领域,主要对城市轨道交通线路电子沙盘的建模和控制进行研究。利用Multigen Creator与3ds MAX建立了城市轨道交通线路场景模型,以Unity3D为三维驱动引擎,Visual Studio C#2015为脚本编译器,实现了城市轨道交通线路沙盘的漫游,道岔的定位和反位的控制、信号机的变化、列车的运行控制以及人机交互的功能。展开更多
为解决城市轨道交通管线复杂且生成管道3D模型仍依赖人机交互的问题,提出一种自动生成参数化BIM(building information modeling)管道连接件的方法。针对因绘图不规范而导致管道的起点和终点坐标无法唯一确定的问题,该方法基于直管中心...为解决城市轨道交通管线复杂且生成管道3D模型仍依赖人机交互的问题,提出一种自动生成参数化BIM(building information modeling)管道连接件的方法。针对因绘图不规范而导致管道的起点和终点坐标无法唯一确定的问题,该方法基于直管中心线坐标,通过空间向量运算自动判断两根、三根和四根管线间应添加的弯头、三通、四通等连接件类型,然后结合标准构件尺寸表计算管件形状和位置参数。此外,利用IFC(industry foundation classes)表达模型,使用C++语言实现模型的自动生成。经验证,该方法可显著提高管道模型生成效率和自动化程度。展开更多
基金supported by the National Natural Science Foundation of China[Grant 41371324].
文摘With the rapid development of photogrammetry,computer vision and three-dimensional(3D)modeling technologies,it is possible to efficiently construct detailed 3D urban models.Accordingly,large corpora of 3D models,such as the Google 3D Warehouse,are now becoming freely available on the web.How to find the proper 3D urban models is a challenging research issue.In this paper,we join shape descriptors and color descriptors for 3D urban model retrieval.The query objects are localized and segmented automatically from the input images by using a new selective search voting algorithm.Through combining the normalization with the light field descriptor,the Horizontal Light Descriptor is introduced to measure the shape similarity among the normalized urban models.The color descriptors are used to represent the color information of the urban models.The two types of descriptors are joined to search 3D urban models similar to the query objects.Experimental results have shown the effectiveness of our approach.
文摘将Unity3D技术应用于城市轨道交通培训领域,主要对城市轨道交通线路电子沙盘的建模和控制进行研究。利用Multigen Creator与3ds MAX建立了城市轨道交通线路场景模型,以Unity3D为三维驱动引擎,Visual Studio C#2015为脚本编译器,实现了城市轨道交通线路沙盘的漫游,道岔的定位和反位的控制、信号机的变化、列车的运行控制以及人机交互的功能。
文摘为解决城市轨道交通管线复杂且生成管道3D模型仍依赖人机交互的问题,提出一种自动生成参数化BIM(building information modeling)管道连接件的方法。针对因绘图不规范而导致管道的起点和终点坐标无法唯一确定的问题,该方法基于直管中心线坐标,通过空间向量运算自动判断两根、三根和四根管线间应添加的弯头、三通、四通等连接件类型,然后结合标准构件尺寸表计算管件形状和位置参数。此外,利用IFC(industry foundation classes)表达模型,使用C++语言实现模型的自动生成。经验证,该方法可显著提高管道模型生成效率和自动化程度。
