The development of 3D technology in oblique photogrammetry and laser point cloud reduced the difficulty and cost of data collecting, but increased the frequency of data upgrading. BIM technology provides meticulous 3D model, and makes the 3D management become possible. The transformation of 3D data collection enables users to collect large amount of 3D data. With the accumulation of 3D data, the multi-source data integrated technology becomes especially important.
With the rapid development of data collecting technology, spatial multi-resource data brings new challenges to GIS data integration and application. The efficient integration of spatial data from different sources and resolutions has important practical meaning for reducing the construction cost of GIS application systems and improving the efficiency of using spatial data.
SuperMap 3D Designer's 3D geographic design engine further strengthens the construction, calculation and processing capabilities of oblique photogrammetry models, TIN terrain, BIM and other data, and makes breaking through in the limitations of traditional GIS software in multi-source 3D spatial data integration, analysis. These progresses help users to build accurate large-scale 3D scenes and to solve various difficulties in the data processing of GIS applications, as well as effectively shorten the project construction cycle.
To integrate and match multi-source data in 3D scene, the first thing is coordinate transformation and data registration. That is to unify BIM, oblique photogrammetry model, point cloud and other GIS data into one coordinate system. SuperMap provides various 3D data coordinate transformation, including: models, grid, images, point clouds, oblique photogrammetry models, etc.
Single coordinate system can only solve the plane issues. Due to the various data precisions, there are deviations in the Z direction that needs to be processed.
1. Terrain and mountain integration
Terrain (TIN) operation includes cropping, tessellation, burrowing, intersections with 3D solid models, and supports real-time previews.
2. Oblique photogrammetry model and the roads, water surfaces integration
The oblique photogrammetry model supports the operations of cropping, burrowing, inlaying, culling suspended objects, and supports real-time preview. Users can view the effect of data processing before the operation.
For instance, when users build road on oblique photogrammetry model, they can inlay 3D road surface with oblique photogrammetry model and set slope parameters based on the designed 3D road centerline to expand the 3D road surface. After that, the final effect of the road map can be checked. What’s more, according to the 3D surface and the oblique photogrammetry model, the amount of excavation and filling can also be calculated, in order to provide a reference for construction.
BIM, oblique photogrammetry model and TIN terrain integration
Through the functions of cropping, burrowing and inlaying of TIN terrain and tilt photography models, the effects of BIM, oblique photogrammetry model and TIN terrain integration can be easily achieved.
BIM data and oblique photogrammetry model usually use different coordinate systems. Before integrating and matching, the conversion operation of coordinate system is conducted. SuperMap not only supports the conversion function of the model data, but also supports the registration function of the model data. These functions can automatically match the BIM model with the specified coordinate system, which requires the inlaying and flattening operation onto the oblique photogrammetry model in BIM model area and to set the slope parameters to achieve smooth transition of data connection.
The height of the large scene terrain and the oblique photogrammetry model may be different and they may cover each other when using together. SuperMap provides two solutions. One is to generate DSM from oblique photogrammetry model and to change the values of terrain grid. This modifies the terrain height by the height of the oblique photogrammetry model. The other one is to generate TIN terrain from terrain data. Then the terrain data can be burrowed and inlayed by the vector data. At the same time, the TIN terrain inlaying function supports the gentle slope parameter setting that can help achieve smooth transition of data connection.