| 3D point cloud data can be acquired rapidly and roundly with Vehicle Laser surveying technique. The data acquired includes the 3D information of reality, and it has advantage in its reality and locality. However, unlike 2D symbol, the 3D point cloud is not suitable for human eye interpretation, and can't be applied for data query and application analysis, etc. Integrating them organically into one program and making them responding each other is the best solution. The idea of the dynamic response discussed in this paper solved the respective limitation of 2D symbol and 3D point cloud, and combined the advantage of both 2D symbol and 3D point cloud.The dynamic response performs as following:before the symbolization of the point cloud, when we click any point in the 3D workstation, the corresponding symbol will be drawn automatically in the relevant position of the 2D map, after the symbolization, the symbol will be demonstrate bright. Similarly, if we select a 2D symbol, the related point cloud will correspondingly demonstrate brightly in the 3D scene.Substantively, the dynamic response of the 3D vehicle laser-point cloud and the 2D symbol is one kind of mapping between the two spatial set. To achieve the dynamic response, we must establish one-to-one mapping relationship between the 3D point cloud with the 2D symbol. In this paper, we realize the dynamic response by establishing the one-to-one mapping of the coordinate system and the geographic object using unique mark respectively. In the dynamic response process, we first realized the point cloud symbolization. The establishment process of the 2D symbol library and the 2D map were demonstrated in detail. Then we load datum, create geometric object and render unique value using the interfaces and methods of the ArcGIS Engine. We mainly used attribute inquiry and the spatial inquiry methods to implement the dynamic response, and used the global variable and the message mechanism during the programming.Finally, taking the 3D point could data acquired by the vehicle laser scanning system for example, we realized the dynamic response of the 3D point cloud and the 2D symbol, using ArcGIS Engine development kit and OpenGL based on the Visual C++platform. |
