Research On Object Oriented Semantic Mapping Of Architectural Structures

With rapid economic and social development,China has entered the stage of urban smart construction.The urban 3D model is the key data for urban smart construction.How to effectively obtain the urban 3D model and achieve accurate 3D reconstruction and display of all elements of modern architecture is a key link in achieving green and intelligent buildings,and also an important foundation for achieving urban smart management.Building Information Modal(BIM)records all data information throughout the entire lifecycle of a building,providing a detailed description of the internal information of the building.However,Three Dimensional Geographic Information System(3D GIS)focuses on model construction in macro scenarios,with limited description of the internal information of the building.The integration of data interaction between the two can achieve complementary advantages and jointly provide a data foundation for the construction of smart cities.However,the two belong to different fields,and there are significant differences in geometric expression,semantic description,topology implementation,and other aspects.Therefore,it is particularly important to achieve the interaction and integration between the two.Industry Foundation Classes(IFC)and City Geography Markup Language(CityGML)are important data formats for BIM and 3D GIS.How to achieve the conversion of IFC to CityGML models is a key challenge in the integration of BIM and3 D GIS.The existing transformation methods can complete the transformation of geometric structure and Semantic information,but there are the following shortcomings in Semantic information expansion and topological information transformation:(1)The current transformation methods often only complete the extension of attribute Semantic information of building components,but do not complete the extension of geometric semantics,such as the extension of stairs,beams,columns,etc.,which makes the Semantic information of this part of building components cannot be accurately expressed after transformation;(2)The topology relationship in IFC is very complex,and direct mapping and transformation is very difficult,so current transformation methods still cannot effectively complete the mapping and transformation of topology information.In view of the existing mapping and transformation mechanism can not effectively solve the complex semantic and topological relationship,this paper establishes a model mapping and transformation logic model from IFC to CityGML,and implements an object-oriented multi-level mapping and transformation system:(1)Expand CityGML data standard based on the multi-level semantic extension model(Building ADE),which overcomes the lack of accurate expression of Semantic information of building components in CityGML after transformation;(2)Reorganize the topological relationship in IFC,and realize the mapping and transformation of topological relationship between models based on the redefined support,embedding,connection,combination,suspension and inclusion of six topological relationship classes.This article focuses on urban buildings and establishes a comprehensive semantic mapping transformation method.The experimental results demonstrate that the method proposed in this article can ensure the conversion of geometric,semantic,and topological information from IFC to CityGML.The converted CityGML model contains the geometric,attribute,and topological information of the IFC model,which can be used for the integration of 3D geographic information systems and building information models,and contributes to the intelligent management of cities.