Method for generating LOD1-grade GIS model through municipal road BIM design model based on ADE

Abstract

The invention discloses a method for generating an LOD1-grade GIS model based on an ADE municipal road BIM design model, and relates to the technical field of municipal road three-dimensional design and geographic information, and the method comprises the steps: reading a road IFC file; obtaining component codes; reading standard component code classification and an LOD level component list; classifying the road components according to the component codes and adding LOD level attributes; generating IFC models corresponding to different LOD levels; basic attributes required by the GML are added; geometric transformation is carried out; extracting a geometric object type required by the GML; discretizing the geometry to form a triangulation network; simplifying the geometric model, and extracting a road basic line type; constructing a virtual stretching body according to the line type of the road foundation; geometric transformation is carried out; based on the ADE, expanding and defining Aligments; and generating the CityGML file. According to the method, the integrity and accuracy of integration of the LOD1-level GIS data and the municipal road BIM data can be improved.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional design of municipal roads and geographic information technology, and particularly relates to a method for generating a LOD1-level GIS model from a BIM design model of a municipal road based on ADE. Background Art

[0002] In the context of the rapid development of smart cities and digital twin technologies, three-dimensional models of municipal roads play an important role in planning, design, management, and maintenance. As two core technologies, Building Information Modeling (BIM) and Geographic Information System (GIS) play important roles in the design stage and the spatial management stage respectively. However, there are significant differences between BIM models and GIS models in terms of data expression, modeling accuracy, and standard specifications. How to achieve efficient conversion and integration between the two has become one of the current research hotspots.

[0003] BIM models provide high-precision geometric and attribute information in the design stage, but directly using them in a GIS environment may lead to data redundancy and performance issues. The LOD1-level GIS model emphasizes simplified expression, especially the abstraction of road routes, which is in sharp contrast to the detailed expression of BIM design models. Therefore, converting a BIM design model into a LOD1-level GIS model not only helps to achieve data lightweighting but also provides more efficient data support for urban planning, infrastructure management, and smart city applications. For this purpose, it is necessary to simplify and process the BIM design model in terms of route extraction, geometric simplification, attribute mapping, etc.

[0004] As an important part of urban infrastructure, the model of a municipal road not only needs to express spatial geometric information but also needs to contain professional attributes such as route design, cross-section structure, and traffic facilities. As a widely used standard for three-dimensional urban models, CityGML provides model expressions at multiple levels of detail. The LOD1 level, as the basic layer of the model, is usually used for regional planning and large-scale scene visualization, mainly focusing on the route and basic geometric form of the road. However, the standard mode of CityGML has incompleteness in the expression of municipal road elements and lacks support for core elements such as routes and cross-sections. For example, it is difficult to express the horizontal alignment (such as straight lines, curves, and transition curves) and vertical section information (such as slopes and elevation changes) of roads in the standard mode. Therefore, it is necessary to define the dedicated semantics and geometric structure of municipal roads based on the Application Domain Extension (ADE) of CityGML to meet the specific requirements of municipal road models.

[0005] In summary, extending CityGML based on ADE and converting the BIM design model of urban roads into a GIS model at LOD1 level is an important technical path to meet the model expression requirements of urban roads. In this process, it is necessary to overcome the limitations of the CityGML standard mode and the difficulties in simplifying the BIM model to the GIS model. By extending semantic definitions, optimizing geometric conversions, and ensuring data consistency, high-quality urban road model data support can be provided for smart city and digital twin applications. Summary of the Invention

[0006] Aiming at the problems of simplification and processing of the BIM design model of urban roads to the GIS model at LOD1 level and the incompleteness of CityGML urban road elements, the embodiments of the present invention provide a method for generating a GIS model at LOD1 level based on ADE for the BIM design model of urban roads, which can improve the integrity and accuracy of the integration of LOD1 level GIS data and urban road BIM data, provide a technical route and a feasible method for the integration of urban road BIM and GIS data, and promote the informatization and intelligent management of urban road projects.

[0007] In the first aspect, the present invention provides a method for generating a GIS model at LOD1 level based on ADE for the BIM design model of urban roads, including:

[0008] Parsing the IFC element categories involved in road components from the road IFC file, classifying the components and attribute data according to the element categories, and obtaining the IFC elements classified by category containing the components and attribute data, where the IFC elements are divided into component elements and attribute elements;

[0009] Querying the extended attributes and extended attribute set data of the components from the attribute elements, connecting the extended attributes and extended attribute set data to the component elements, screening out the component coding data, and connecting the component coding data to the component elements;

[0010] Reading the standard component coding classification and the LOD level component list, classifying the road components according to the component coding and adding the LOD level attributes, generating the IFC models corresponding to different LOD levels according to the component elements with the added LOD level attributes, and selecting the component elements with the LOD level attribute value of LOD1;

[0011] According to the screened LOD1 component elements, adding the basic attributes required by GML, and performing geometric conversion on the LOD1 component elements after adding the GML attributes;

[0012] According to the geometric elements after geometric transformation, set the geometric object types of the geometric elements according to the geometric coding parameters, discretize the geometry to form a triangular mesh, simplify the geometric model according to the triangular mesh, extract the basic road alignment, construct a virtual extrusion body according to the basic road alignment, and perform geometric transformation on the virtual extrusion body;

[0013] Modify the underlying Schema file of the CityGML Transportation theme, inherit from the Road element, and create a new Alignment element to express the route elements at LOD1;

[0014] Import the custom Schema file, construct an Alignment writing module, input the elements after geometric transformation of the virtual extrusion body, write the file, and generate the RoadADEOfLod1.gml file, which is the GIS model at LOD1 level.

[0015] In some instances, various component geometric entities and basic attributes are stored in the component elements, and the extended attributes and extended attribute set data of each component entity are stored in the attribute elements.

[0016] In some instances, querying the extended attributes and extended attribute set data of the component from the attribute elements, connecting the extended attributes and extended attribute set data to the component elements, filtering out the component coding data, and connecting the component coding data to the component elements includes:

[0017] Construct a FeatureJoiner module, input various component elements and attribute elements, query the extended attributes and extended attribute set data of the component from the IfcPropertySet of the attribute elements according to the ifc_property_set{} data of the component elements, and connect the extended attributes and extended attribute set data to the component elements, and output the connected component elements;

[0018] Construct a Tester module, input the connected component elements, and use ifc_property_set_name = basic attribute as the filtering condition to filter out the component elements with component coding, where the attribute value of the basic attribute is the component coding;

[0019] Construct an AttributeManager module, input the component elements with component coding, add the component coding attribute, add the component coding data to the component elements, and output the component elements.

[0020] In some instances, the reading of the standard component coding classification and the LOD-level component list includes:

[0021] Build a component coding classification table reading module to read the component classification and coding rules, and the LOD classification rules. The component classification and coding rules comply with the requirements of the "Unified Standard for the Application of Highway Engineering Information Model" (JTG / T 2420-2021), and are divided into 4 major categories: route, subgrade components, pavement components, and traffic engineering and roadside facility components, and output the component classification and coding, and the LOD classification.

[0022] In some instances, the classification of road components according to component codes and adding LOD level attributes includes:

[0023] Build a FeatureJoiner module, input the component features with added component coding data, the LOD classification rules, and the component classification and coding, perform a comparison query through the component codes to determine the LOD level of the component features, add the LOD level attributes to the component features and output.

[0024] In some instances, the geometric transformation of the LOD1 component features after adding GML attributes includes:

[0025] Build a GeometryPartExtractor module, input the LOD1 component features after adding GML attributes, and extract the selected geometric features based on geometric XQuery;

[0026] Build a GeometryCoercer module, input the selected geometric features, and reset the geometric object type of the features;

[0027] Build a Deaggregator module, input the geometric features after resetting the features, and form components after decomposing the aggregate features;

[0028] Build an Aggregator module, input the geometric features after decomposing the aggregate, and merge the geometric shapes of the features into heterogeneous or homogeneous aggregates;

[0029] Build a GeometryRefiner module, input the merged geometric features, and refine the geometric shapes of the features.

[0030] In some instances, the discretization of the geometry to form a triangular mesh includes:

[0031] Build a Triangulator module, input the extracted geometric objects, perform triangular mesh processing to form discrete triangular meshes;

[0032] Build a MeshMerger module, input the discrete triangular meshes, and perform aggregation processing.

[0033] In some instances, the simplification of the geometric model according to the triangular mesh to extract the road foundation line type includes:

[0034] Build the HullReplacer module, input the aggregated triangular mesh, reconstruct the geometric shape with a convex polygon, and form the outer contour.

[0035] Build the CenterlineReplacer module, input the generated outer contour, extract its centerline to form the road basic alignment and output it.

[0036] In some examples, the construction of the virtual extrusion body according to the road basic alignment includes:

[0037] Build the GeometryExtractor module, input the road basic alignment, and extract its geometric shape.

[0038] Build 2 Extruder modules respectively, input the geometric shape, and stretch it successively from the two normal directions of its vertical section to build a virtual extrusion body.

[0039] In some examples, the geometric transformation of the virtual extrusion body includes:

[0040] Build the GeometryCoercer module, input the virtual extrusion body, and reset the geometric object type of the feature.

[0041] Build the Deaggregator module, input the reset geometric feature, decompose its aggregated feature, and form its components.

[0042] Build the Aggregator module, input the decomposed geometric features, and merge the geometric shapes of the features into heterogeneous or homogeneous aggregates.

[0043] Build the GeometryRefiner module, input the merged geometric features, and refine the geometric shapes of the features.

[0044] Build the GeometryExtractor module, input the refined feature, and extract its geometric shape.

[0045] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following beneficial effects can be achieved:

[0046] For the components involved in the BIM design model of municipal roads, classification and coding are carried out according to the provisions of the "Unified Standard for the Application of Highway Engineering Information Model" (JTG / T 2420-2021), and division is carried out according to the LOD level; on this basis, for the component models corresponding to the LOD1 level, a series of data converters are developed, and at the same time, the Alignment element is defined based on the CityGML ADE extension framework, and the BIM design model of municipal roads is generated into a LOD1 level GIS model. This method can improve the integrity and accuracy of the integration of LOD1 level GIS data and municipal road BIM data, and provides a technical route and feasible method for the integration of municipal road BIM and GIS data. It can solve the problems of simplification and processing of the BIM design model of municipal roads to the LOD1 level GIS model and the incompleteness of CityGML municipal road elements, improve the integrity and accuracy of the integration of LOD1 level GIS data and municipal road BIM data, and promote the informatization and intelligent management of municipal road projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0048] Figure 1 is a schematic flowchart of the method provided by the embodiment of the present invention;

[0049] Figure 2 is a schematic diagram of the original model provided by the embodiment of the present invention;

[0050] Figure 3 is a schematic diagram of the LOD1 level GIS model provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0052] In the following description, specific embodiments of the present invention will be described with reference to steps and symbols executed by one or more computers, unless otherwise specified. Therefore, these steps and operations will be referred to as being executed by a computer several times. As used herein, computer execution includes operations of a computer processing unit on electronic signals representing data in a structured form. This operation transforms the data or maintains its position in the computer's memory system, which can reconfigure or otherwise change the operation of the computer in a manner well known to those skilled in the art. The data structure in which the data is maintained is a physical location in the memory, which has specific characteristics defined by the data format. However, the principles of the present invention are described in the above text, which is not intended to be limiting, and those skilled in the art will understand that the following various steps and operations can also be implemented in hardware.

[0053] As used herein, the term "module" or "unit" can be regarded as a software object executed on the computing system. Different components, modules, engines, and services herein can be regarded as implementation objects on the computing system. The devices and methods herein are preferably implemented in software, but of course can also be implemented in hardware, all within the protection scope of the present invention.

[0054] Those skilled in the art of the present technology can understand that, unless specifically stated otherwise, the singular forms "a", "an", and "the" used herein can also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present invention means the presence of features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, "connected" or "coupled" as used herein can include wireless connection or wireless coupling. The phrase "and / or" used herein includes all or any unit and all combinations of one or more related listed items.

[0055] In an embodiment of the present invention, a method for generating a LOD1-level GIS model based on an ADE for a municipal road BIM design model is provided. As Figure 1 shown, it includes the following steps:

[0056] S1, reading the road IFC file: constructing a road IFC file reading module, the original model is as Figure 2As shown, read the road IFC file, parse out the IFC element categories involved in the road components from it, classify the components and attribute data according to the element categories, and output the IFC elements classified by category containing the component and attribute data, such as IfcBuildingElement Proxy, IfcCivilElement, IfcPipeSegment, IfcWall, IfcSlab, IfcFooting, IfcSpace, IfcPropertySet, etc. The IFC elements are mainly divided into two categories. One category is component elements, such as IfcBuildingElement Proxy, IfcCivilElement, IfcPipeSegment, IfcWall, IfcSlab, IfcFooting, IfcSpace, which store geometric entities and basic attributes of various components; the other category is attribute elements, such as IfcPropertySet, which store extended attributes and extended attribute set data of each component entity.

[0057] S2. Obtain the component code: Construct multiple FeatureJoinerAndTester modules, input various component elements and attribute elements output from S1, query the extended attributes and extended attribute set data of the component from the attribute element IfcPropertySet according to the ifc_property_set{} data of the component element, connect the extended attributes and extended attribute set data to the component element, then filter out the component code data from them, and connect the component code data to the component element, so that in addition to storing the original component geometric entity and basic attribute data, the component element also stores the component code data, and output various component elements;

[0058] According to the above solution, in step S2, the FeatureJoinerAndTester module is composed of multiple sub-modules, specifically:

[0059] S201. Construct a FeatureJoiner module, input various component elements and attribute elements output from S1, query the extended attributes and extended attribute set data of the component from the attribute element IfcPropertySet according to the ifc_property_set{} data of the component element, and connect the extended attributes and extended attribute set data to the component element, and output the connected component elements;

[0060] S202. Construct a Tester module, input the component elements in S201, and use "ifc_property_set_name = basic attribute" as the filtering condition, where the attribute value of "basic attribute" is the component code, so as to filter out the component elements with the component code;

[0061] S203. Build the AttributeManager module, input the component elements in S202, add the "component code" attribute, so as to add the component code data to the component elements, and output the component elements.

[0062] S3. Read the standard component code classification and the LOD level component list. Specifically: Build a component code classification table reading module, read the component classification and coding rules, and the LOD classification rules. Among them, the component classification and coding rules comply with the requirements of the "Unified Standard for the Application of Highway Engineering Information Model" (JTG / T 2420-2021), and are divided into 4 major categories: route, subgrade component, pavement component, and traffic engineering and roadside facility components, and output the component classification and coding, and the LOD classification.

[0063] S4. Classify the road components according to the component code and add the LOD level attribute. Specifically: Build a FeatureJoiner module, input the component elements in S203, the LOD classification rules, and the component classification and coding in S3, and perform a comparison query through the component code to determine the LOD level of the component elements, add the LOD level attribute to the component elements and output.

[0064] S5. Generate the IFC model corresponding to different LOD levels. Specifically: Build a TestFilterOfLod module, input the component elements in S4, and output the component elements with the LOD level attribute value of LOD1 by screening their LOD level attribute information.

[0065] S6. Add the basic attributes required by GML. Specifically: Build an AttributeCreator module, input the LOD1 component elements screened in S5, add the basic attribute information required by the CityGML model such as "citygml_lod_name, gml_id, gml_name", perform attribute mapping and output.

[0066] S7. Perform geometric transformation. Specifically: Build a ConvertGeometry module, input the LOD1 component elements in S6, perform geometric transformation and output.

[0067] According to the above solution, in step S7, the ConvertGeometry module is composed of multiple sub-modules. Specifically:

[0068] S701. Build a GeometryPartExtractor module, input the LOD1 component elements in S6, extract the geometric elements selected (the geometric object name is Body) based on geometric XQuery and output;

[0069] S702, construct a GeometryCoercer module, input the selected geometric elements in S701, reset the geometric object type of the elements and output;

[0070] S703, construct a Deaggregator module, input the geometric elements in S702, decompose its aggregate elements, form its components and output;

[0071] S704, construct an Aggregator module, input the geometric elements in S703, merge the geometric shapes of the elements into heterogeneous or homogeneous aggregates and output;

[0072] S705, construct a GeometryRefiner module, input the geometric elements in S704, "refine" the geometric shapes of the elements and output.

[0073] S8, extract the required geometric object types for GML, specifically: construct a GeometryExtractor module, input the geometric elements in S705, and extract the geometric object types of the elements according to the geometric coding parameter settings (set to GML v3.2.1) and output.

[0074] S9, discretize the geometry to form a triangular mesh, specifically:

[0075] S901, construct a Triangulator module, input the geometric objects extracted in S8, perform triangular mesh processing, form triangular meshes and output;

[0076] S902, construct a MeshMerger module, input the discrete triangular meshes generated in S901, perform aggregation processing on them and output.

[0077] S10, simplify the geometric model, extract the road foundation line type, specifically:

[0078] S1001, construct a HullReplacer module, input the aggregated triangular mesh in S902, reconstruct its geometric shape with a convex polygon, form the outer contour and output;

[0079] S1002, construct a CenterlineReplacer module, input the outer contour generated in S1001, extract its centerline to form the road foundation line type and output.

[0080] S11, construct a virtual extrusion body according to the road foundation line type, specifically:

[0081] S1101, construct a GeometryExtractor module, input the road foundation line type obtained in S1002, extract its geometric shape and output;

[0082] S1102. Build two Extruder modules respectively, input the geometric shapes in S1101, stretch them successively from the two normal directions of their vertical sections, build a virtual stretched body and output it.

[0083] S12. Perform geometric transformation, specifically:

[0084] S1201. Build a GeometryCoercer module, input the virtual stretched body in S1102, reset the geometric object type of the elements and output;

[0085] S1202. Build a Deaggregator module, input the geometric elements in S1201, decompose their aggregate elements, form their components and output;

[0086] S1203. Build an Aggregator module, input the geometric elements in S1202, merge the geometric shapes of the elements into heterogeneous or homogeneous aggregates and output;

[0087] S1204. Build a GeometryRefiner module, input the geometric elements in S1203, "refine" the geometric shapes of the elements and output;

[0088] S1205. Build a GeometryExtractor module, input the elements in S1204, extract their geometric shapes and output.

[0089] S13. Define Alignment based on the ADE extension, specifically: Modify the underlying Schema file of the CityGML Transportation theme, inherit from the Road element, and create a new Alignment element to express the route elements of LOD1.

[0090] S14. Generate a CityGML file, specifically: Import the custom Schema file in S13, build an Alignment write module, input the elements in S1205, write the file, and generate the RoadADEOfLod1.gml file, which is the GIS model of LOD1 level, as Figure 3 shown. The GIS model of LOD1 level is the basic alignment of the road, used to express the positioning, routing and topological relationship between routes.

[0091] The above has introduced in detail a method for generating a LOD1-level GIS model based on an ADE for a municipal road BIM design model provided by an embodiment of the present invention. In this article, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for generating a LOD1 level GIS model from a municipal road BIM design model based on ADE, characterized in that: include: The IFC element categories involved in the road components are parsed from the road IFC file, and the components and attribute data are classified according to the element categories to obtain the classified IFC elements containing the components and attribute data, wherein the IFC elements are divided into component elements and attribute elements; Query the extended attribute and extended attribute set data of the component from the attribute element, connect the extended attribute and extended attribute set data to the component element, filter out the component coding data, and connect the component coding data to the component element; Read the standard component code classification and LOD level component list, classify the road components according to the component code and add LOD level attributes, generate IFC models corresponding to different LOD levels according to the component elements with LOD level attributes added, and select the component elements with LOD level attribute value LOD1; According to the selected LOD1 component elements, basic attributes required by GML are added, and geometric transformation is performed on the LOD1 component elements after the GML attributes are added; According to the geometric elements after geometric transformation, the geometric object type of the geometric elements is extracted according to the geometric encoding parameter setting, the geometry is discretized to form a triangulated network, the geometric model is simplified according to the triangulated network, the road basic line type is extracted, the virtual stretch body is constructed according to the road basic line type, and the virtual stretch body is geometrically transformed; Modify the underlying Schema file of the CityGML Transportation theme, inherit from the Road element, and create a new Alignment element to express the route element of LOD1; Import the custom Schema file, build the Alignment writing module, input the elements after geometric transformation of the virtual stretch body, write out the file, and generate the RoadADEOfLod1.gml file, which is the GIS model of LOD1 level.

2. The method according to claim 1, characterized in that The component elements store various component geometric entities and basic attributes, and the attribute elements store the extended attributes and extended attribute set data of each component entity.

3. The method according to claim 2, characterized in that The step of querying the extended attributes and extended attribute set data of the component from the attribute elements, connecting the extended attributes and extended attribute set data to the component elements, screening out the component coding data, and connecting the component coding data to the component elements includes: Construct the FeatureJoiner module, input various component elements and attribute elements, query the component's extended attributes and extended attribute set data from the attribute element IfcPropertySet according to the ifc_property_set{} data of the component element, connect the extended attributes and extended attribute set data to the component element, and output the connected component element; Construct the Tester module, input the connected component elements, use ifc_property_set_name = basic attribute as the screening condition, and screen out the component elements with component codes, where the attribute value of the basic attribute is the component code; Build an AttributeManager module, input a component feature with a component code, add a component code attribute, add the component code data to the component feature, and output the component feature.

4. The method according to any one of claims 1 to 3, characterized in that: The reading of standard component coding classification and LOD level component list includes: Build a component coding classification table reading module to read the component classification and coding rules and LOD classification rules. The component classification and coding rules comply with the requirements of the "Uniform Standard for the Application of Highway Engineering Information Model" (JTG / T 2420-2021) and are divided into four categories: routes, roadbed components, pavement components, traffic engineering and facilities along the line. Output component classification and coding, and LOD classification.

5. The method according to claim 4, characterized in that The road components are classified according to the component codes and LOD level attributes are added, including: Construct the FeatureJoiner module, input the component elements with component coding data added, LOD classification rules, and component classification and coding, perform comparative query through component coding to determine the LOD level of the component elements, add LOD level attributes to the component elements and output them.

6. The method according to claim 5, characterized in that The geometric transformation of the LOD1 component elements after adding the GML attributes includes: Construct the GeometryPartExtractor module, input the LOD1 component elements after adding GML attributes, and extract the selected geometric elements based on geometric XQuery; Build the GeometryCoercer module, input the selected geometric features, and reset the geometric object type of the features; Construct the Deaggregator module, input the geometric elements after resetting the elements, and decompose the aggregate elements into components; Construct the Aggregator module, input the geometric elements after decomposing the aggregates, and merge the geometric figures of the elements into heterogeneous or homogeneous aggregates; Construct the GeometryRefiner module, input the merged geometric features, and refine the geometry of the features.

7. The method according to claim 6, characterized in that The step of discretizing the geometry to form a triangulated network includes: Construct the Triangulator module, input the extracted geometric objects, perform triangulation processing, and form discrete triangulation meshes; Construct the MeshMerger module, input the discrete triangulated mesh, and perform aggregation processing.

8. The method according to claim 7, characterized in that The method of extracting the road basic line type according to the simplified geometric model of the triangulated network includes: Construct the HullReplacer module, input the aggregated triangulated network, and reconstruct the geometric shape with convex polygons to form the outer contour; Construct the CenterlineReplacer module, input the generated outer contour, extract the centerline from it to form the basic road line shape and output it.

9. The method according to claim 8, characterized in that The step of constructing a virtual stretching body according to the road basic line type includes: Construct the GeometryExtractor module, input the basic road line shape, and extract its geometric shape; Construct two Extruder modules respectively, input the geometric shape, and stretch it from the two normal directions of its vertical cross section in turn to construct a virtual stretched body.

10. The method according to claim 9, characterized in that The geometric transformation of the virtual stretched body includes: Construct the GeometryCoercer module, input the virtual stretch body, and reset the geometric object type of the feature; Construct the Deaggregator module, input the reset geometric elements, decompose its aggregate elements into its components; Construct the Aggregator module, input the decomposed geometric elements, and merge the geometric figures of the elements into heterogeneous or homogeneous aggregates; Construct the GeometryRefiner module, input the merged geometric features, and refine the geometry of the features; Construct the GeometryExtractor module, input the refined features, and extract their geometric shapes.

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