Method for automatically extracting CityGML LOD models from IFC model

Abstract

A method for automatically extracting CityGML LOD models from an IFC model comprises the following four steps of: analyzing the IFC model, and filtering the IFC model, the IFC model geometric reconstruction and the IFC model geometric semantic reorganization on the basis of the semantic mapping relationship; filtering the entity elements based on semantics on the basis of analysis; filtering out entity elements having a mapping relation with the CityCrMLLOD4, wherein the geometry of the entity is the self-defined geometry information of the IFC model; carrying out coordinate conversion and expression mode conversion on the geometric information; generating first layer middle geometric information; secondly, carrying out corresponding geometric reconstruction on the first layer of middle geometric information to generate second layer of middle geometric information, carrying out reorganization on the second layer of middle geometric information, outputting the reorganized geometric information and semantic information to generate a CityGML LOD4 model, and finally generating a CiTyGML LOD3-LOD1 model according to a coordinating relation of the LOD4 and LOD3-LOD1.. Automatic extraction and generation from the IFC model to the CityGML LOD4 model are achieved, and the defect of a coordination conversion method between CityGML LOD4 and CityGML LOD3- LOD1 is overcome.

Description

technical field [0001] The invention relates to a method for GIM model analysis and model automatic extraction, in particular to a method for automatically extracting CityGML LOD 1-LOD4 models from an IFC model. Background technique [0002] The IFC (Industry Foundation Classes) standard is a widely used standard in the field of Building Information Model (BIM), and the City Geography Markup Language (CityGML) is a standard in the field of Three Dimensional Geographic Information System (3DGIS). , the two belong to completely different fields, so there are great differences in geometry, semantics, LOD level, application scenarios, etc. The semantic expressions of IFC and CityGML are almost completely different. The semantic information expressed by IFC is far more than that of CityGML. To convert the IFC model to the CityGML model, there are currently some studies on the conversion of the IFC model to the CityGML LOD1-LOD3 model. The IFC model is converted to CityGML LOD1-L...

AI Technical Summary

Problems solved by technology

[0004] The present invention provides a method for automatically extracting the CityGML LOD 1-LOD4 model from the IFC model, which overcomes the fact that there is no conversion tool in the prior art and can only realize partial conversion from the IFC model to the CityGML LOD1-LOD3 model, and cannot realize the conversion from the IFC model to CityGML The automatic extraction and generation of the LOD4 model, and the lack of a coordinated conversion method between CityGML LOD4 and CityGMLLOD3-LOD1, the technical solution is as follows:

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