BIM technology keeps developing and being applied in a lot of industries, such as planning, real state, architecture, water, electricity, transportation and so on. This is a new challenge to the 3D GIS. The 3D spatial information needs to make a closed loop from data access, processing, rendering to data analysis and the results in GIS platform and provides a solid technical basis for the applications of related industries and provides reliable basis for management and decision-making.
SuperMap provides the data export plug-in for the BIM mainstream design software, such as Revit, Bentley, CATIA and so on. It supports exporting data vertex and attribute information at one time and classifying the information according to type or layer. The exported data not only preserves the features of instantiated BIM data, but also generates multiple Levels of Detail, which can improve the performance of data loading and browsing in the 3D GIS platform. Meanwhile, the exported data also preserves the topological integrity and closure of BIM data. The topological 3D objects can carry out spatial operations, spatial relations query, spatial analysis, Boolean calculation with terrain data, etc.
After accessing, BIM data will be stored in the model dataset. Each record of dataset represents a BIM entity object, including model geometry information (GeoModel 3D) and attribute information. In order to meet the docking requirements of more BIM design software, the SuperMap GIS 9D component products provide the develop interface of GeoModel 3D. Users can parse the skeleton, material, texture and attribute information of each object of the BIM data, and construct the model object through the corresponding interface, and input the BIM data into the dataset.
BIM data editing and lightweight
BIM + GIS applications cover the whole life cycle of BIM. SuperMap partners completed a number of typical application cases in the planning, design, construction and maintenance of BIM based on SuperMap GIS. Besides, they also find technical difficulties in data accessing, data management, data matching and modal plotting of the BIM+GIS integration.
To solve the technical difficulties in BIM+GIS integration, SuperMap made a technical breakthrough in lossless accessing of BIM mainstream data, accurate matching between BIM data and GIS platform, real time plotting BIM model and seamless integration of BIM data and 3D model. Besides, based on 3D data model, SuperMap archived the analysis and operational capability in the GIS platform and developed the 3D GIS to the major engineering application fields like architecture, bridge, tunnel, water and dam. Those technologies and developments provide a powerful technical and platform support for the application of BIM+GIS.
BIM data editing
The SuperMap 3D platform can not only edit the geometric and attribute information of BIM objects, but also edit a sub object of BIM objects, such as the texture replacement and adjustment. SuperMap 3D platform also supports to export OSGB, S3M, GLTIF, STL, OFF, DAE and many other kinds of data formats. What’s more, SuperMap iDesktop 9D products provide the batch editing function of the model dataset, which can be used to translate and rotate the entire dataset layer. Thus the users can edit the BIM model location more conveniently.
BIM data lightweight
There are different accuracy requirements of BIM data in different fields, so there are different lightweight operations to import BIM data into 3D GIS platform according to project demands. SuperMap iDesktop 9D products provide various operations for BIM data lightweight and triangulation network (TIN), including the functions of extracting shells, TIN simplification, sub object simplification (delete), deleting duplicate vertex, normal calculation (delete), model split, model merging, etc. Let’s take TIN simplification as an example.
1. Boundary Constraint: Tick this option if you want to remain the boundary line of objects.
2. Simplification Condition: Click “Calc Triangle Cnt”to process a statistics, the result will be displayed in the [ ] which is the number of the biggest and smallest triangled plane.
3. Simplification Information: Adjust the scale bar of simplification rate and preview the simplification result on the window life-hand side. As shown below: display the number of triangled planes and the percentage of simplification.
Analysis operation based on BIM data
Based on 2D & 3D integration data model, SuperMap new generation 3D GIS added new functions of 3D entity data model, spatial operation of 3D entity objects, spatial relations query (including relations of cross, contain, within, overlap, disjoint, etc.), spatial analysis and seamless accessing between BIM mainstream data and 3D entity models. With the help of 3D entity data model, SuperMap new generation 3D GIS achieved analysis and computing capability of BIM data in the GIS platform.
1. Boolean operation
BIM data is processed by intersection, union and difference operation to get new 3D entity objects.
2. Spatial relations query
Spatial relations query between BIM data and 3D entity objects will be widely applied in urban design and architectural design
3. Get section
Sectioning the BIM data to get the 2D floor plans.
4. 3D boundary
BIM data extracts the boundary face to match the terrain and location accurately.
5. Boolean operation with terrain
The boolean operation between BIM data and terrain can make the tunnel in the mountain model.
6. Batch modify the objects’ color and visibility
Share and publish BIM data
In order to load and browse the BIM data in 3D scene more efficiently, we need to generate 3D tiles of S3M format though the ways of LOD (level of detail), instantiation storage and plotting and rough layer objects filtration. Thus the BIM data can be efficiently rendered in desktop, browsers and mobiles clients to solve the problems of BIM data publishing and loading on various clients for the users.
SuperMap iClient3D for WebGL based on HTML5 WebGL technology is a lightweight 3D client development platform. It supports hardware accelerated visual rendering technology and eliminates the dependence of 3D rendering on plug-ins. Users can review 3D service efficiently without downloading or installing any plug-ins.
BIM + GIS Integration Technologies has become a hotspot for urban planning and construction. The value of BIM could be extended by combining with GIS. SuperMap GIS will keep developing BIM industrial applications, supporting more BIM formats, carrying larger BIM data, providing more BIM functions, and cooperate with BIM partners to complete BIM and GIS combination technology solution.