A method for constructing 3D scenes for BIM digital applications in highway engineering

Abstract

This invention relates to a method for constructing 3D scenes for BIM digital applications in highway engineering, belonging to the field of BIM digital application technology for highway engineering. The method includes: sorting out the granularity of the BIM model, its business attributes, and digital application business; constructing a model dictionary; forming a BIM model structure table based on the digital application business and the model dictionary; generating BIM model geometric data while acquiring BIM model business data; optimizing the BIM model; storing the acquired BIM model business data; converting the BIM model and terrain model into spatial 3D model tile data; merging the terrain model and BIM model; publishing BIM model services, terrain model services, and business data query services; and creating a 3D scene. This invention solves the shortcomings of traditional methods that cannot fully meet the requirements of large-scale, rapid, and portable construction of 3D scenes for BIM digital applications in highway engineering, and offers superior efficiency and ease of promotion and application.

Description

Technical Field

[0001] This invention belongs to the field of BIM digital application technology for highway engineering, and specifically relates to a method for constructing a three-dimensional scene for BIM digital application in highway engineering. Background Technology

[0002] With the increasing demand for highway engineering projects, BIM (Building Information Modeling) digitization technology has brought tremendous application value to the highway engineering field. Three-dimensional scenes are the most intuitive and effective way to present BIM information in highway engineering. As my country's highway transportation network has largely taken shape, a method for rapidly constructing three-dimensional digital application scenes is particularly important for the large-scale, rapid, and portable implementation of BIM digitization in highway engineering, given this vast infrastructure network.

[0003] Traditional BIM digital applications for highway engineering primarily rely on commercial computer rendering software for 3D scene construction. This involves importing BIM models and terrain models for integrated visualization, and then displaying business attributes on separate pages. However, this approach presents several problems for large-scale highway engineering scenarios: Firstly, the BIM model can only display geometric data; component business information must be displayed as a whole on a separate page, unable to be linked with the BIM model's geometric data. Secondly, commercial rendering software has limited capacity for individual 3D scenes, leading to rendering lag in large-scale highway engineering digital models. Thirdly, conflicts and collisions exist between the BIM model and the terrain model, resulting in long fusion processing cycles and significant update difficulties. Finally, commercial rendering software has limited functionality and cannot integrate actual business needs.

[0004] In summary, existing technologies for constructing 3D scenes in traditional BIM digital applications for highway engineering have significant shortcomings and cannot fully meet the needs of large-scale, rapid, and portable 3D scene construction for highway engineering BIM digital applications. Therefore, overcoming the deficiencies of existing technologies is an urgent problem to be solved in this technical field. Summary of the Invention

[0005] This invention provides a method for constructing 3D scenes for BIM digital applications in highway engineering, which solves the problems of linking BIM model geometric data with business attributes, rendering large-scale BIM models, fusion processing of BIM models and terrain models, and integration of actual business functions in traditional 3D scene construction methods. It can meet the needs of large-scale, rapid, and portable construction of 3D scenes for BIM digital applications in highway engineering.

[0006] To achieve the above objectives, the present invention provides the following technical method:

[0007] A method for constructing a 3D scene for BIM digital application in highway engineering, wherein the 3D scene for BIM digital application in highway engineering includes a highway engineering BIM model and a highway engineering terrain model;

[0008] The method for constructing a 3D scene for BIM digital application in highway engineering includes the following steps:

[0009] Step (1): Analyze the requirements of the highway engineering BIM digital application project to be carried out, and sort out the BIM model granularity, BIM model business attribute structure, and digital application business in conjunction with the standard documents.

[0010] Step (2): Construct a model dictionary library based on the specification documents, BIM model granularity, and BIM model business attribute structure; the model dictionary library includes a BIM model classification and coding table and a unified structure document of BIM model business attributes.

[0011] Step (3): Based on the digital application business and combined with the model dictionary library, form a BIM model composition table;

[0012] Step (4): Based on the BIM model composition table, generate BIM model geometric data and simultaneously acquire BIM model business data;

[0013] Step (5): Optimize the BIM model based on its geometric data;

[0014] Step (6) is to store the obtained BIM model business data to form a business database;

[0015] Step (7) converts the BIM model and terrain model into spatial three-dimensional model tile data, and sets a unique identification code to associate the BIM model geometric data and business data;

[0016] Step (8) is to integrate the terrain model and the BIM model;

[0017] Step (9) publish the spatial three-dimensional model tile data corresponding to the merged BIM model and terrain model as BIM model service and terrain model service through server software;

[0018] Step (10): Create BIM model business data query service;

[0019] Step (11): Integrate the services published in steps (9) and (10) to create a 3D scene.

[0020] Furthermore, preferably, in step (1), the owner's requirements for BIM digital application in highway engineering are analyzed, and in conjunction with the standard documents, the granularity of the BIM model, the business attribute structure of the BIM model, and the digital application business are sorted out. Specific methods include:

[0021] (1.1) Analyze the highway engineering BIM digital application projects to be carried out, and determine the highway engineering infrastructure entity composition of the digital projects to be carried out by combining the classification and coding types defined in the specification documents, determine the structural hierarchy relationship of various entities, and form the BIM model granularity.

[0022] (1.2) Analyze the requirements of the highway engineering BIM digital application projects to be carried out, combine the attribute set defined in the specification documents, associate the project data and unify the attribute structure to form the business attribute structure of the BIM model.

[0023] (1.3) Analyze the requirements of the highway engineering BIM digital application project to be carried out, determine the functional requirements of the application, and form a digital application business requirements document.

[0024] Furthermore, preferably, the specific method of step (2) is as follows:

[0025] (2.1) Based on the BIM model granularity determined in step (1), the type of highway engineering infrastructure is obtained. According to the type, the classification code, facility name, classification type and classification specification name defined in the specification document are obtained, thereby constructing the classification and coding table of the BIM model.

[0026] The columns in the BIM model classification and coding table are classification code, facility name, classification specification name, and classification type, which respectively represent the unique identifier of the infrastructure classification type, the infrastructure classification type name, the reference specification document for the infrastructure classification, and the type of the infrastructure classification; each row in the table corresponds to a BIM model.

[0027] (2.2) Based on the business attribute structure of the BIM model determined in step (1), and according to the type of highway engineering infrastructure corresponding to the BIM model, the attribute structure information is extracted from the specification document to obtain the unified structure document of the business attributes of the BIM model; in addition, a "classification code" column is added to the unified structure document of the business attributes of the BIM model, and the value is the classification code value in the classification and coding table of the BIM model, so as to realize the association between the classification and coding table of the BIM model and the unified structure document of the business attributes of the BIM model.

[0028] (2.3) The classification and coding table of BIM models and the unified structure document of business attributes of BIM models together constitute the model dictionary library.

[0029] Furthermore, preferably, the specific method of step (3) is as follows:

[0030] (3.1) Based on the needs of the highway engineering BIM digital application projects to be carried out, an identification code shall be constructed according to the principle of uniquely identifying highway engineering infrastructure;

[0031] (3.2) Obtain the actual naming of infrastructure in actual highway engineering projects;

[0032] (3.3) Based on the classification of infrastructure, query the classification code corresponding to the type from the model dictionary;

[0033] (3.4) Determine the hierarchical structure of each BIM model based on the BIM model granularity obtained in step (1);

[0034] (3.5) Construct a BIM model composition table using identification codes, actual naming, classification codes and hierarchical structure.

[0035] Furthermore, preferably, in step (4):

[0036] (4.1) Based on the component models determined in the BIM model composition table, use modeling tools to produce each component model, and set the name of each model to the corresponding "identifier code" field value in the BIM model composition table.

[0037] BIM model geometric data refers to the data structure organization that presents objects in a display device, including coordinate vertices, drawing indexes, color and texture information;

[0038] (4.2) Based on the infrastructure type and in conjunction with the model dictionary, determine the unified structure of business attributes corresponding to the type, form a table of business attributes to be filled in based on the unified structure of business attributes, and add an "identifier code" column to the table to associate with the specific model; the person filling in the table extracts the business data of the corresponding model from existing materials such as drawings and documents, queries the corresponding identifier code from the BIM model composition table, and fills in the obtained business data and identifier code into the table of business attributes to be filled in.

[0039] BIM model business attributes refer to the information that needs to be integrated for the digital application of BIM in highway engineering. Specific applications require specific analysis, such as dimensional information and quantity information in the design phase, and progress information, quality information, and event information in the construction phase.

[0040] Furthermore, preferably, the specific method of step (5) is as follows: taking the facets in the model geometry data produced in step (4) as the granularity, optimization is achieved by reducing the number of drawing indices in a single facet; the facets in the model geometry data refer to a set of face regions composed of drawing indices with consistent normal directions;

[0041] The specific method of step (6) is as follows: Based on the business attribute table filled in step (4), construct a business database according to each column of the table, and save the filled business attributes into the business database. Each record in the business database is uniquely identified by the "identifier code".

[0042] Furthermore, preferably, the specific method of step (8) is as follows:

[0043] Extract the vertical projection contour area of ​​the BIM model's geometric data on the plane; obtain all BIM models that intersect with the terrain area, and then obtain the vertical projection contour area of ​​the BIM model on the plane.

[0044] The contour areas extracted from the two professional BIM models of roadbed and culvert are compared with the spatial three-dimensional model tile data of the terrain model to perform terrain clipping operation;

[0045] The contour area extracted from the bridge professional BIM model is used to perform terrain mosaic operation with the spatial three-dimensional model tile data of the terrain model.

[0046] Using a tunnel-specific BIM model and spatial 3D model tile data of the terrain model, terrain excavation operations are performed.

[0047] Furthermore, preferably, the specific method for querying in step (10) is as follows:

[0048] Using the identification code attribute of the BIM model, the data record corresponding to the identification code is first obtained from the business database. Then, the classification coding attribute of the data record is used to obtain the unified structure of business attributes of the BIM model from the model dictionary. All attribute names in the unified structure of business attributes are traversed, and the attribute values ​​corresponding to the same attribute name are extracted from the business data records. The attribute names are replaced according to the Chinese names of the business attribute set records. Finally, the business data with the agreed Chinese names is returned as the query result.

[0049] Furthermore, preferably, the specific method of step (11) is as follows:

[0050] By using the SDK provided by the Ceisum platform or the SuperMap iClient3D platform, BIM model services and terrain model services can be retrieved and integrated into digital applications to form a 3D base map scene that supports business applications.

[0051] In this invention, the 3D scene of BIM digital application for highway engineering includes the following elements:

[0052] Highway engineering BIM model: contains geometric data of the actual physical parameters of various infrastructures in highway engineering and business attribute data bound to the infrastructure.

[0053] Highway engineering terrain model: contains geometric data of the actual physical parameters of the terrain within the scope of the highway engineering project.

[0054] In this invention, the BIM model granularity refers to the smallest entity of the infrastructure to be digitized for each profession according to the division of highway engineering profession, and specifies the hierarchical relationship between each entity;

[0055] BIM model business attributes refer to the information assigned to the BIM model at different stages of the highway engineering industry, such as dimensional information and quantity information in the design stage, and schedule information, quality information, and event information in the construction stage.

[0056] Digital application services refer to the functional requirements that owners need to achieve in digital scenarios, such as clicking on the BIM model to query the associated business attributes, infrastructure construction simulation, etc.

[0057] Standard documents refer to standard and specification documents issued and implemented by the state, industry or local governments, such as the "Unified Standard for Application of Highway Engineering Information Modeling" (JTG / T 2420-2021), the "Standard for Application of Highway Engineering Design Information Modeling" (JTG / T 2421-2021), and the "Specification for Highway Engineering Information Modeling Part 1: Unified Technical Requirements" (DB51 / T 3092-2023). These documents specify the classification and coding of BIM model types and the attribute set of unified BIM model definitions.

[0058] This invention combines a unified set of attributes defined in the specification documents with project data and the unified set of attributes to form a business attribute structure for the BIM model, thus determining the data source for subsequent attribute table filling.

[0059] In this invention, the unified structure document for business attributes of the BIM model is a description document of the unified structure of business attributes associated with the BIM model, and the attribute information is extracted according to the specification document. Preferably, the document further adds a "classification code" attribute, the value of which is the "classification code" field value in the classification and coding table of the BIM model. This attribute establishes a one-to-one correspondence between the BIM model and the business attribute structure. The document also specifies the Chinese name, English keywords, unit, and associated values ​​for each attribute.

[0060] In this invention, the BIM model structure table refers to the hierarchical structure table of infrastructure to be digitized for various highway specialties in a highway engineering BIM digitization application project. The columns in the table are, in order: identifier code, actual facility name, classification code, and parent facility identifier code, which respectively represent the unique identification symbol of a highway engineering infrastructure, the actual name of the infrastructure in the project, the code of the corresponding BIM model in the BIM model classification and coding table defined in the model dictionary, and the unique identification symbol of the parent facility from a structural perspective.

[0061] In this invention, the production of BIM model geometric data is carried out by defining the granularity of geometric data production through the BIM model structure table. The production party uses modeling tools such as Revit, Civil 3D, Bentley, SketchUp, Blender, and highway engineering BIM design software to produce each component model, and the name of each model is set to the corresponding "identifier code" field value in the BIM model composition table.

[0062] In this invention, the specific method for acquiring BIM model business data is as follows: Personnel extract the corresponding model's business data from drawings, documents, and other materials; query the corresponding identifier code from the BIM model structure table; and fill the obtained business data and identifier code into the table of business attributes to be filled, thus forming the final BIM model business data. Specifically, the attribute set of a certain type of BIM model can be determined from the unified business attribute document in the model dictionary library. Based on the attribute set, business data is formed and filled into the table of business attributes to be filled. An "identifier code" column is added to the table to associate it with the specific model, thereby forming the final BIM model business data.

[0063] In this invention, spatial 3D model tile data is a data format suitable for the transmission, exchange, and sharing of spatial 3D model data. It stores data and attributes of different levels of model refinement. Through spatial 3D model tile data, it is possible to carry and render large-scale digital models of highway engineering. It requires that the BIM model's identification code be converted into spatial 3D model tile data as attributes and geometric data. Through this spatial 3D model tile data, the association between the BIM model's identification code and geometric data is realized.

[0064] Common spatial 3D model tile data formats include S3M, 3DTiles, I3S, etc., which can be generated using tools such as SuperMap iDesktopX, Ceisum, and ArcGIS.

[0065] In step (8) of this invention, fusion refers to processing the terrain model in the conflict and collision area between the terrain model and the BIM model, including: terrain hole excavation, terrain mosaicking, and terrain clipping; based on the spatial three-dimensional model tile data converted in step (7), fusion processing is performed without modifying the original BIM model and terrain model;

[0066] Terrain excavation refers to performing spatial Boolean difference calculations between a BIM model that traverses the terrain model and the terrain model.

[0067] Terrain mosaicking refers to the process of reducing the terrain height within the intersection area of ​​the terrain model and the BIM model to a given depth value.

[0068] Terrain clipping refers to the process of hollowing out the terrain model within the intersection area of ​​the terrain model and the BIM model.

[0069] Extract the vertical projection outline of the BIM model's geometric data onto a plane. Using the projection plane acquisition function provided by the modeling tool, obtain all BIM models that intersect with the terrain area, and then use modeling tools such as Revit to obtain the vertical projection outline of these BIM models on the plane. Highway engineering BIM models are divided into multiple disciplines: route, roadbed, bridge, tunnel, culvert, and traffic safety. Among these, the disciplines that intersect with the terrain model include roadbed, bridge, and culvert; therefore, it is necessary to extract the vertical projection outline of the BIM models for these three disciplines.

[0070] Terrain model fusion processing based on projected contour regions. Contour regions extracted from the roadbed and culvert BIM models are used to perform terrain clipping operations with the spatial 3D model tile data of the terrain model; contour regions extracted from the bridge BIM model are used to perform terrain mosaic operations with the spatial 3D model tile data of the terrain model; and terrain excavation operations are performed using the tunnel BIM model and the spatial 3D model tile data of the terrain model. These operations are implemented using tools such as SuperMap iDesktopX, Ceisum, and ArcGIS. Subsequent fusion updates only require adding regions to the previous fusion results, significantly reducing the difficulty of fusion updates.

[0071] In step (9) of this invention, accessing BIM model geometric data, BIM model attributes, and terrain model geometric data via services can significantly enhance the carrying capacity of 3D scenes in digital applications and can also be integrated into various business applications. Here, "service" refers to the function of providing data transmission and exchange over the Internet via the HTTP network protocol.

[0072] The operations described are implemented using tools such as Geoserver, Tomcat, and SuperMap iServer. The specific steps are subject to the methods used by each software to publish HTTP network services.

[0073] The query service in step (10) of this invention can be implemented through various programming language frameworks and published for use through server software.

[0074] Compared with the prior art, the beneficial effects of this invention are as follows:

[0075] This invention provides a method for constructing 3D scenes for BIM digital applications in highway engineering in a modular, rapid, and portable manner. Compared with traditional methods, it improves efficiency by 50%. The data carrying capacity and rendering capabilities of the constructed 3D scenes are significantly enhanced, overcoming the problem that traditional commercial rendering software does not support large-scale model rendering. The 3D scenes of digital applications are constructed in the form of services. By calling BIM model services, terrain model services, and BIM model business data query services, a 3D base map is built and integrated into multiple types of digital applications. The digital applications can be developed and implemented according to the specific business needs, solving the problem of the single business function of traditional commercial rendering software.

[0076] This invention stores BIM model geometric data and identification codes based on spatial 3D model tile data. In a 3D scene, the identification code is obtained through the geometric data in the spatial 3D model tile data of the BIM model. Business attributes can be obtained through the identification code, realizing the connection between BIM model geometric data and business data, and overcoming the problem that traditional commercial rendering software does not support the linkage between BIM model geometric data and business data.

[0077] This invention establishes a constraint modeling scheme and a business information entry scheme based on the BIM model structure table system, which separates the model generation process and the business information sorting process, making it easier for modelers and business personnel to work in parallel, thereby improving the efficiency of scene construction from the perspective of work mode.

[0078] Based on the conflict and collision between BIM models and terrain models, this invention provides a solution for integrating BIM models and terrain models from different disciplines by utilizing the planar projection area of ​​BIM model geometric data. This solution includes fusion operations such as terrain hole excavation, terrain mosaicking, and terrain clipping. Compared with traditional processing methods, this solution greatly improves fusion efficiency and can quickly update the fusion by adding new fusion areas, significantly reducing the difficulty of fusion updates.

[0079] This invention starts from the actual needs of digital applications and combines national, industry or local standards and specifications to implement the information in actual projects. By separating the information from the digital application business through a model dictionary and a business database, it enables digital applications to be associated with multiple standards and specifications. When a new specification is released, there is no need to rebuild the digital application. Instead, the new specification information is simply replaced in the model dictionary. This method greatly reduces the cost of implementing digital applications due to the specifications. Attached Figure Description

[0080] Figure 1 This is a flowchart of the method for constructing a three-dimensional scene for BIM digital application in highway engineering according to the present invention;

[0081] Figure 2This is a demonstration image of a 3D scene of highway engineering BIM digital application constructed using the method provided by this invention in an application example of this invention. Detailed Implementation

[0082] The present invention will now be described in further detail with reference to the embodiments.

[0083] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the field or according to the product instructions. Materials or equipment whose manufacturers are not specified are all conventional products that can be obtained by purchase.

[0084] A method for constructing a 3D scene for BIM digital application in highway engineering, wherein the 3D scene for BIM digital application in highway engineering includes a highway engineering BIM model and a highway engineering terrain model;

[0085] The method for constructing a 3D scene for BIM digital application in highway engineering includes the following steps:

[0086] Step (1): Analyze the requirements of the highway engineering BIM digital application project to be carried out, and sort out the BIM model granularity, BIM model business attribute structure, and digital application business in conjunction with the standard documents.

[0087] Step (2): Construct a model dictionary library based on the specification documents, BIM model granularity, and BIM model business attribute structure; the model dictionary library includes a BIM model classification and coding table and a unified structure document of BIM model business attributes.

[0088] Step (3): Based on the digital application business and combined with the model dictionary library, form a BIM model composition table;

[0089] Step (4): Based on the BIM model composition table, generate BIM model geometric data and simultaneously acquire BIM model business data;

[0090] Step (5): Optimize the BIM model based on its geometric data;

[0091] Step (6) is to store the obtained BIM model business data to form a business database;

[0092] Step (7) converts the BIM model and terrain model into spatial three-dimensional model tile data, and sets a unique identification code to associate the BIM model geometric data and business data;

[0093] Step (8) is to integrate the terrain model and the BIM model;

[0094] Step (9) publish the spatial three-dimensional model tile data corresponding to the merged BIM model and terrain model as BIM model service and terrain model service through server software;

[0095] Step (10): Create BIM model business data query service;

[0096] Step (11): Integrate the services published in steps (9) and (10) to create a 3D scene.

[0097] Specifically, in step (1), the owner's requirements for BIM digital application in highway engineering are analyzed. Based on the relevant specifications, the granularity of the BIM model, the structure of BIM model business attributes, and the digital application business are outlined. Specific methods include:

[0098] (1.1) Analyze the highway engineering BIM digital application projects to be carried out, and determine the highway engineering infrastructure entity composition of the digital projects to be carried out by combining the classification and coding types defined in the specification documents, determine the structural hierarchy relationship of various entities, and form the BIM model granularity.

[0099] (1.2) Analyze the requirements of the highway engineering BIM digital application projects to be carried out, combine the attribute set defined in the specification documents, associate the project data and unify the attribute structure to form the business attribute structure of the BIM model.

[0100] (1.3) Analyze the requirements of the highway engineering BIM digital application project to be carried out, determine the functional requirements of the application, and form a digital application business requirements document.

[0101] Specifically, the method for step (2) is as follows:

[0102] (2.1) Based on the BIM model granularity determined in step (1), the type of highway engineering infrastructure is obtained. According to the type, the classification code, facility name, classification type and classification specification name defined in the specification document are obtained, thereby constructing the classification and coding table of the BIM model.

[0103] The columns in the BIM model classification and coding table are classification code, facility name, classification specification name, and classification type, which respectively represent the unique identifier of the infrastructure classification type, the infrastructure classification type name, the reference specification document for the infrastructure classification, and the type of the infrastructure classification; each row in the table corresponds to a BIM model.

[0104] (2.2) Based on the business attribute structure of the BIM model determined in step (1), and according to the type of highway engineering infrastructure corresponding to the BIM model, the attribute structure information is extracted from the specification document to obtain the unified structure document of the business attributes of the BIM model; in addition, a "classification code" column is added to the unified structure document of the business attributes of the BIM model, and the value is the classification code value in the classification and coding table of the BIM model, so as to realize the association between the classification and coding table of the BIM model and the unified structure document of the business attributes of the BIM model.

[0105] (2.3) The classification and coding table of BIM models and the unified structure document of business attributes of BIM models together constitute the model dictionary library.

[0106] Specifically, the method for step (3) is as follows:

[0107] (3.1) Based on the needs of the highway engineering BIM digital application projects to be carried out, an identification code shall be constructed according to the principle of uniquely identifying highway engineering infrastructure;

[0108] (3.2) Obtain the actual naming of infrastructure in actual highway engineering projects;

[0109] (3.3) Based on the classification of infrastructure, query the classification code corresponding to the type from the model dictionary;

[0110] (3.4) Determine the hierarchical structure of each BIM model based on the BIM model granularity obtained in step (1);

[0111] (3.5) Construct a BIM model composition table using identification codes, actual naming, classification codes and hierarchical structure.

[0112] Specifically, in step (4):

[0113] (4.1) Based on the component models determined in the BIM model composition table, use modeling tools to produce each component model, and set the name of each model to the corresponding "identifier code" field value in the BIM model composition table.

[0114] BIM model geometric data refers to the data structure organization that presents objects in a display device, including coordinate vertices, drawing indexes, color and texture information;

[0115] (4.2) Based on the infrastructure type and in conjunction with the model dictionary, determine the unified structure of business attributes corresponding to the type, form a table of business attributes to be filled in based on the unified structure of business attributes, and add an "identifier code" column to the table to associate with the specific model; the person filling in the table extracts the business data of the corresponding model from existing materials such as drawings and documents, queries the corresponding identifier code from the BIM model composition table, and fills in the obtained business data and identifier code into the table of business attributes to be filled in.

[0116] BIM model business attributes refer to the information that needs to be integrated for the digital application of BIM in highway engineering. Specific applications require specific analysis, such as dimensional information and quantity information in the design phase, and progress information, quality information, and event information in the construction phase.

[0117] Specifically, the specific method of step (5) is as follows: taking the facets in the model geometry data produced in step (4) as the granularity, optimization is achieved by reducing the number of drawing indices in a single facet; the facets in the model geometry data refer to a set of face regions composed of drawing indices with consistent normal directions;

[0118] The specific method of step (6) is as follows: Based on the business attribute table filled in step (4), construct a business database according to each column of the table, and save the filled business attributes into the business database. Each record in the business database is uniquely identified by the "identifier code".

[0119] Specifically, the method for step (8) is as follows:

[0120] Extract the vertical projection contour area of ​​the BIM model's geometric data on the plane; obtain all BIM models that intersect with the terrain area, and then obtain the vertical projection contour area of ​​the BIM model on the plane.

[0121] The contour areas extracted from the two professional BIM models of roadbed and culvert are compared with the spatial three-dimensional model tile data of the terrain model to perform terrain clipping operation;

[0122] The contour area extracted from the bridge professional BIM model is used to perform terrain mosaic operation with the spatial three-dimensional model tile data of the terrain model.

[0123] Using a tunnel-specific BIM model and spatial 3D model tile data of the terrain model, terrain excavation operations are performed.

[0124] Specifically, the specific method for querying in step (10) is as follows:

[0125] Using the identification code attribute of the BIM model, the data record corresponding to the identification code is first obtained from the business database. Then, the classification coding attribute of the data record is used to obtain the unified structure of business attributes of the BIM model from the model dictionary. All attribute names in the unified structure of business attributes are traversed, and the attribute values ​​corresponding to the same attribute name are extracted from the business data records. The attribute names are replaced according to the Chinese names of the business attribute set records. Finally, the business data with the agreed Chinese names is returned as the query result.

[0126] Specifically, the method for step (11) is as follows:

[0127] By using the SDK provided by the Ceisum platform or the SuperMap iClient3D platform, BIM model services and terrain model services can be retrieved and integrated into digital applications to form a 3D base map scene that supports business applications.

[0128] Application Examples

[0129] This example uses the construction of a 3D scene for a highway tunnel digital BIM application in a real-world project. This example requires establishing BIM models for all tunnel-related entities; the classification and coding of the tunnel BIM models must conform to the standard document "Application Standard for Highway Engineering Design Information Model" (JTG / T 2421-2021); business attributes must also conform to the specifications of this standard; the business application requires that clicking on a BIM model in the 3D scene displays all the attributes of that model according to the standard, and the attribute names must be displayed using the Chinese names specified in the standard; the 3D scene rendering must be smooth and lag-free.

[0130] like Figure 1 As shown, a method for constructing a 3D scene for BIM digital application in highway engineering includes the following steps:

[0131] S1. Analyze the owner's requirements for BIM digital application in highway engineering, and in conjunction with the standard documents, sort out the BIM model granularity, BIM model business attribute structure, and digital application business.

[0132] Specifically, based on standard specifications and the actual structure of the tunnel, all infrastructure entities included in the tunnel, as well as the structural relationships between these entities, were identified to determine the granularity of the tunnel's BIM model. The results are shown below:

[0133] Level 1 type entities: Left tunnel, Right tunnel;

[0134] Second-level type entity:

[0135] The left tunnel includes the left tunnel entrance portal, left tunnel section #1, left tunnel section #2, left tunnel section #3, left tunnel section #4, vehicular auxiliary passage, left drainage section #1, left drainage section #2, left drainage section #3, left drainage section #4, left road surface section #1, left road surface section #2, left road surface section #3, left road surface section #4, and vehicular auxiliary passage road surface.

[0136] The right tunnel includes the right tunnel entrance portal, right tunnel body section #1, right tunnel body section #2, right tunnel body section #3, right tunnel body section #4, right tunnel body section #5, right drainage and waterproofing section #1, right drainage and waterproofing section #2, right drainage and waterproofing section #3, right drainage and waterproofing section #4, right drainage and waterproofing section #5, right road surface section #1, right road surface section #2, right road surface section #3, right road surface section #4, and right road surface section #5.

[0137] Third-level type entity:

[0138] The left-side entrance portal includes a ring frame, arch wall, invert arch, invert arch backfill, portal protection, open-cut backfill section #1, and open-cut backfill section #2.

[0139] The left tunnel section #1 includes the left maintenance tunnel (cable trough) and the right maintenance tunnel (cable trough);

[0140] The left tunnel section #2 includes shotcrete, arch walls, invert arch, invert arch backfill, left maintenance tunnel (cable trough), and right maintenance tunnel (cable trough);

[0141] The left tunnel section #3 includes shotcrete, arch walls, invert arch, invert arch backfill, left maintenance tunnel (cable trough), and right maintenance tunnel (cable trough);

[0142] The left tunnel section #4 includes shotcrete, arch wall, invert arch, invert arch backfill, left maintenance tunnel (cable trough), and right maintenance tunnel (cable trough);

[0143] The vehicular auxiliary passage includes shotcrete and arched walls;

[0144] The left-side drainage section #1 includes the left-side ditch and the right-side ditch.

[0145] The left-side drainage section #2 includes the left-side ditch and the right-side ditch.

[0146] The left-side drainage section #3 includes the left-side ditch and the right-side ditch.

[0147] The left-side drainage section #4 includes the left-side ditch and the right-side ditch.

[0148] The left lane road section #1 includes a cement concrete surface layer and an asphalt concrete surface layer.

[0149] The left lane road section #2 includes a cement concrete surface layer and an asphalt concrete surface layer.

[0150] The left lane road section #3 includes a cement concrete surface layer and an asphalt concrete surface layer.

[0151] The left lane road section #4 includes a cement concrete surface layer and an asphalt concrete surface layer.

[0152] The road surface of the vehicular auxiliary lane includes a cement concrete surface layer;

[0153] The right-side entrance portal includes a ring frame, arch wall, invert arch, invert arch backfill, portal protection, open-cut backfill section #1, and open-cut backfill section #2.

[0154] The right tunnel section #1 includes the left maintenance tunnel (cable trough) and the right maintenance tunnel (cable trough);

[0155] The right tunnel section #2 includes shotcrete, arch walls, invert arch, invert arch backfill, left maintenance tunnel (cable trough), and right maintenance tunnel (cable trough);

[0156] The right tunnel section #3 includes shotcrete, arch walls, invert arch, invert arch backfill, left maintenance tunnel (cable trough), and right maintenance tunnel (cable trough);

[0157] The right tunnel section #4 includes shotcrete, arch wall, invert arch, invert arch backfill, left maintenance tunnel (cable trough), and right maintenance tunnel (cable trough);

[0158] The right tunnel section #5 includes shotcrete, arch walls, invert arch, invert arch backfill, left maintenance tunnel (cable trough), and right maintenance tunnel (cable trough);

[0159] The right-side drainage section #1 includes the left-side ditch and the right-side ditch.

[0160] The right-side drainage section #2 includes the left-side ditch and the right-side ditch.

[0161] The right-side drainage section #3 includes the left-side ditch and the right-side ditch.

[0162] The right-side drainage section #4 includes the left-side ditch and the right-side ditch.

[0163] The right-side drainage section #5 includes the left-side ditch and the right-side ditch.

[0164] The right lane road section #1 includes a cement concrete surface layer and an asphalt concrete surface layer.

[0165] The right lane road section #2 includes a cement concrete surface layer and an asphalt concrete surface layer.

[0166] The right lane road section #3 includes a cement concrete surface layer and an asphalt concrete surface layer.

[0167] The right lane road section #4 includes a cement concrete surface layer and an asphalt concrete surface layer.

[0168] The right lane road section #5 includes a cement concrete surface layer and an asphalt concrete surface layer.

[0169] Specifically, based on the requirements of this tunnel digital application, it is required to display the business attributes of the tunnel BIM model, which should only include design information, including: dimension information and quantity information.

[0170] Specifically, based on the requirements of this tunnel digital application, the constructed tunnel BIM model 3D scene is required to include the following: web-based visual representation, smooth rendering, ability to query business attributes by clicking on the BIM model, strict adherence to the standard definition of business attribute sets, and strict consistency between the displayed names of business attributes and the Chinese names defined in the standard.

[0171] S2. Based on the standard documents, BIM model granularity, and BIM model business attribute structure, construct a model dictionary library, including: a BIM model classification and coding table, and a unified structure document for BIM model business attributes.

[0172] Specifically, based on the specification documents and the BIM model granularity determined in step S1, a classification and coding table for the tunnel BIM model is created. The attribute values ​​of this table are extracted according to the specification documents, as shown in Table 1.

[0173] Table 1 Classification and Coding of Tunnel BIM Models

[0174] Classification coding Facility Name Classification Standard Name Classification type 17-04.00.00.00 Tunnel sub-facilities JTG / T 2421-2021 Sub-facilities 17-04.01.00.00 Cave Gate JTG / T 2421-2021 Sub-facilities 17-04.02.00.00 Cave body JTG / T 2421-2021 Sub-facilities 17-04.03.00.00 Vehicle auxiliary lane JTG / T 2421-2021 Sub-facilities 17-04.04.00.00 Drainage JTG / T 2421-2021 Sub-facilities 17-02.01.00.00 pavement JTG / T 2421-2021 Sub-facilities 18-06.01.03.00 Frame JTG / T 2421-2021 member 18-06.05.01.00 Arch wall JTG / T 2421-2021 member 18-06.05.02.00 Upward arch JTG / T 2421-2021 member 18-06.05.03.00 Backfilling of the inverted arch JTG / T 2421-2021 member 18-02.03.00.00 Cave entrance protection JTG / T 2421-2021 member 18-06.02.02.00 Myeongdong backfill JTG / T 2421-2021 member 18-06.66.09.00 Maintenance access road (cable trough) JTG / T 2421-2021 member 18-06.04.05.00 Shotcrete JTG / T 2421-2021 member 18-02.02.02.00 Roadside Ditch JTG / T 2421-2021 member 18-03.01.01.00 cement concrete surface layer JTG / T 2421-2021 member 18-03.01.02.00 Asphalt concrete surface layer JTG / T 2421-2021 member

[0175] Specifically, based on the BIM model business attributes determined in the specification document and step S1, attribute information is extracted from the specification document to create a unified structure document for the business attributes of the tunnel BIM model. Corresponding classification code attributes are added to the document, and the classification code attribute values ​​are set to the classification code values ​​corresponding to the BIM model. Here, the unified business attributes of tunnel sub-facilities are used as an example, as shown in Table 2. For the unified structure of business attributes for other BIM models, please refer to the specification. The dictionary is built based on MySQL database software.

[0176] Table 2. Unified Structure Document for Tunnel Sub-facilities' Business Attributes

[0177]

[0178]

[0179] S3. Based on the digital application business and combined with the model dictionary, a BIM model composition table is formed. Specifically, the identification code is composed of the BIM model hierarchy, the pinyin abbreviation of the BIM model type name, and the BIM model segment number: the name is extracted from the drawings; the classification code is queried from Table 1; the parent-child hierarchical structure is filled in according to the three-level BIM model granularity relationship sorted out in step S1; the BIM model segments are specified according to the requirements. In this application, the left tunnel is specified to be divided into 4 segments and the right tunnel into 5 segments; finally, the BIM model composition table of this tunnel is formed, as detailed in Table 3.

[0180] Table 3. Composition of Tunnel BIM Model

[0181]

[0182]

[0183]

[0184]

[0185] S4. Based on the requirements of the upcoming highway engineering BIM digital application project, and in conjunction with the BIM model structure table, carry out the work of producing BIM model geometric data and filling in business data.

[0186] The production of BIM model geometric data is carried out by defining the granularity of geometric data production through the BIM model structure table. The production team uses modeling tools such as Revit, Civil 3D, Bentley, SketchUp, Blender, and highway engineering BIM design software to produce each component model, and the name of each model is set to the corresponding "identifier code" field value in the BIM model structure table.

[0187] The process of filling in BIM model business data begins with the unified business attribute document in the model dictionary determining the attribute set for a specific type of BIM model. Based on this attribute set, a table of business attributes to be filled is created, and an "identifier code" column is added to the table to link to the specific model. For example, Table 4 details the table of business attributes to be filled based on the unified business attribute document for tunnel sub-facilities (Table 2). Specific issues related to business attributes are analyzed on a case-by-case basis; here, only the business attribute columns of "Classification Code, Tunnel Name, Starting Point Chainage, Ending Point Chainage, Quantity of Work, and Other Requirements" are considered. The personnel filling in the data extract the corresponding model's business data from drawings, documents, and other materials, look up the corresponding identifier code from the BIM model structure table, and then fill in the table of business attributes to be filled with the obtained business data and identifier code.

[0188] Table 4: Table of Business Attributes to be Filled in for Tunnel Sub-facilities

[0189]

[0190] S5. Optimize the tunnel BIM model. Using the facets in the geometric data of the model produced in step S4 as the granularity, optimization is achieved by reducing the number of drawing indices in a single facet. Based on this approach, the PolygonCruncher tool is used to perform facet reduction on the BIM model.

[0191] S6. Conduct the data entry of the tunnel BIM model into the database. Based on the business attribute table filled in step S4, construct a business database according to each column of the table, and save the filled business attributes into the business database. Each record in the database is uniquely identified by an identifier code. This application uses MySQL database software to construct the business database.

[0192] S7. Convert the tunnel BIM model and terrain model into spatial 3D model tile data. This application is based on the S3M spatial 3D model tile data specification. SuperMap iDesktopX software is used to convert the BIM model and terrain model into corresponding spatial 3D model tile data, and the identifier code of each tunnel BIM model is saved as an attribute into the spatial 3D model tile data.

[0193] S8. Initiate the fusion of the tunnel BIM model and the terrain model. Using SuperMap iDesktopX software, perform terrain excavation operations using the corresponding spatial 3D model tile data of the tunnel BIM model and the terrain model to achieve fusion.

[0194] S9. The processed BIM model and terrain model corresponding spatial 3D model tile data are published as BIM model services and terrain model services via server software. This application uses the SuperMap iServer platform to publish spatial 3D model tile data services.

[0195] S10. Create a BIM model business data query service. Using the BIM model's identifier attribute, first retrieve the data record corresponding to that identifier from the business database. Then, using the data record's classification coding attribute, retrieve the unified business attribute structure of the BIM model from the model dictionary. Iterate through all attribute names in the unified business attribute structure, extract the attribute values ​​corresponding to the same attribute name from the business data records, and replace the attribute names with the Chinese names specified in the business attribute set records. Finally, return the query results as business data with the agreed-upon Chinese names. This service process is implemented using the Spring Boot framework, and service deployment and use are achieved through the framework itself.

[0196] S11. Integrate BIM model spatial 3D model tile data services, terrain model spatial 3D model tile data services, and BIM model business data query services. Utilize SuperMap's iClient3D for Ceisum framework to create a 3D scene, forming a 3D base map scene that supports business applications. The final tunnel BIM application 3D scene constructed in this example is as follows: Figure 2 As shown.

[0197] Through the practice of the method of this invention, in the implementation of the 3D scene construction of tunnel BIM application, compared with the traditional method of building 3D scenes by relying on commercial computer rendering software, in terms of functionality, it realizes the dynamic association between the geometric data and business information of the tunnel BIM model, realizes the smooth rendering of large-scale highway engineering digital models based on spatial 3D model tile technology, realizes the rapid integration of BIM model and terrain model conflict collisions, and realizes the process of free customization of business functions by developers, independent of the functions provided by commercial rendering software. In terms of efficiency, the entire implementation realizes the separation of model generation process and business information sorting process, ensuring that model generation and business information filling are carried out in parallel, improving efficiency by 50%.

[0198] In the construction and implementation of the 3D scenario for BIM application in this tunnel, starting from the actual digital application needs, and combining the standard and specification document "Application Standard for Highway Engineering Design Information Model" (JTG / T 2421-2021) issued and implemented by the Ministry of Transport, the standard information is implemented in the actual project. Through the model dictionary library and business database, the standard information and digital application business are separated, and the digital application can be associated with multiple standards and specifications. When a new specification is released, there is no need to rebuild the digital application. It is only necessary to replace the new specification information in the model dictionary library. This method greatly reduces the cost of implementing digital applications due to standard documents.

[0199] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for constructing a 3D scene for BIM digital application in highway engineering, characterized in that, The 3D scenario for BIM digital application in highway engineering includes the highway engineering BIM model and the highway engineering terrain model; The method for constructing a 3D scene for BIM digital application in highway engineering includes the following steps: Step (1): Analyze the requirements of the highway engineering BIM digital application project to be carried out, and sort out the BIM model granularity, BIM model business attribute structure, and digital application business in conjunction with the standard documents. Step (2): Construct a model dictionary library based on the specification documents, BIM model granularity, and BIM model business attribute structure; the model dictionary library includes a BIM model classification and coding table and a unified structure document of BIM model business attributes. Step (3): Based on the digital application business and combined with the model dictionary library, form a BIM model composition table; Step (4): Based on the BIM model composition table, generate BIM model geometric data and simultaneously acquire BIM model business data; Step (5): Optimize the BIM model based on its geometric data; Step (6): Store the obtained BIM model business data to form a business database; Step (7) convert the BIM model and terrain model into spatial three-dimensional model tile data, and set a unique identification code to associate the BIM model geometric data and business data; Step (8) integrates the terrain model and the BIM model; Step (9) publish the spatial three-dimensional model tile data corresponding to the merged BIM model and terrain model as BIM model service and terrain model service through server software; Step (10): Create a BIM model business data query service; Step (11): Integrate the services published in steps (9) and (10) to create a 3D scene; The specific method for step (3) is as follows: (3.1) Based on the requirements of the highway engineering BIM digital application projects to be carried out, and with the principle of uniquely identifying highway engineering infrastructure, construct an identification code; (3.2) Obtain the actual naming of infrastructure in actual highway engineering projects; (3.3) Based on the classification type of the infrastructure, query the classification code corresponding to that type from the model dictionary; (3.4) Determine the hierarchical structure of each BIM model based on the BIM model granularity obtained in step (1); (3.5) Construct a BIM model composition table using identification codes, actual naming, classification codes, and hierarchical structure; The specific method for step (8) is as follows: Extract the vertical projection contour area of ​​the BIM model's geometric data on the plane; obtain all BIM models that intersect with the terrain area, and then obtain the vertical projection contour area of ​​the BIM model on the plane. The contour areas extracted from the two professional BIM models of roadbed and culvert are compared with the spatial three-dimensional model tile data of the terrain model to perform terrain clipping operation; The contour area extracted from the bridge professional BIM model is used to perform terrain mosaic operation with the spatial three-dimensional model tile data of the terrain model. Using a tunnel-specific BIM model and spatial 3D model tile data of the terrain model, terrain excavation operations are performed.

2. The method for constructing a three-dimensional scene for BIM digital application in highway engineering according to claim 1, characterized in that, In step (1), the owner's requirements for BIM digital application in highway engineering are analyzed. Based on the relevant specifications, the granularity of the BIM model, the structure of BIM model business attributes, and the digital application business are outlined. Specific methods include: (1.1) Analyze the highway engineering BIM digital application projects to be carried out, and determine the highway engineering infrastructure entity composition of the digital projects to be carried out by combining the classification and coding types defined in the specification documents, determine the structural hierarchy relationship of various entities, and form the BIM model granularity; (1.2) Analyze the requirements of the highway engineering BIM digital application projects to be carried out, combine the attribute set defined in the specification documents, associate the project data and unify the attribute structure to form the business attribute structure of the BIM model; (1.3) Analyze the requirements of the highway engineering BIM digital application project to be carried out, determine the functional requirements of the application, and form a digital application business requirements document.

3. The method for constructing a three-dimensional scene for BIM digital application in highway engineering according to claim 1, characterized in that, The specific method for step (2) is as follows: (2.1) Based on the BIM model granularity determined in step (1), the type of highway engineering infrastructure is obtained. According to the type, the classification code, facility name, classification type and classification specification name defined in the specification document are obtained, thereby constructing the classification and coding table of the BIM model; The columns in the BIM model classification and coding table are classification code, facility name, classification specification name, and classification type, which respectively represent the unique identifier of the infrastructure classification type, the infrastructure classification type name, the reference specification document for the infrastructure classification, and the type of the infrastructure classification; each row in the table corresponds to a BIM model. (2.2) Based on the business attribute structure of the BIM model determined in step (1), and according to the type of highway engineering infrastructure corresponding to the BIM model, the attribute structure information is extracted from the specification document to obtain the unified structure document of the business attributes of the BIM model. In addition, a classification code column is added to the unified structure document of business attributes of BIM models. The value corresponds to the classification code value in the classification and coding table of BIM models, thereby realizing the association between the classification and coding table of BIM models and the unified structure document of business attributes of BIM models. (2.3) The classification and coding table of BIM models and the unified structure document of business attributes of BIM models together constitute the model dictionary library.

4. The method for constructing a three-dimensional scene for BIM digital application in highway engineering according to claim 1, characterized in that, In step (4): (4.1) Based on the component models determined in the BIM model composition table, use modeling tools to produce each component model, and set the name of each model to the corresponding identifier field value in the BIM model composition table. BIM model geometric data refers to the data structure organization that presents objects in a display device, including coordinate vertices, drawing indexes, color and texture information; (4.2) Based on the infrastructure type and in conjunction with the model dictionary, determine the unified structure of business attributes corresponding to the type, form a table of business attributes to be filled based on the unified structure of business attributes, and add an identification code column to the table to associate with the specific model; the person filling in the table extracts the business data of the corresponding model from the existing materials, queries the corresponding identification code from the BIM model composition table, and fills in the obtained business data and identification code into the table of business attributes to be filled. BIM model business attributes refer to the information that needs to be integrated for the digital application of BIM in highway engineering.

5. The method for constructing a three-dimensional scene for BIM digital application in highway engineering according to claim 4, characterized in that: The specific method of step (5) is as follows: taking the facets in the model geometry data produced in step (4) as the granularity, optimization is achieved by reducing the number of drawing indices in a single facet; the facets in the model geometry data refer to a set of face regions composed of drawing indices with consistent normal directions; The specific method of step (6) is as follows: Based on the business attribute table filled in step (4), construct a business database according to each column of the table, and save the filled business attributes into the business database. Each record in the business database is uniquely identified by the identifier code.

6. The method for constructing a three-dimensional scene for BIM digital application in highway engineering according to claim 1, characterized in that, The specific method for querying step (10) is as follows: Using the identification code attribute of the BIM model, the data record corresponding to the identification code is first obtained from the business database. Then, the classification coding attribute of the data record is used to obtain the unified structure of business attributes of the BIM model from the model dictionary. All attribute names in the unified structure of business attributes are traversed, and the attribute values ​​corresponding to the same attribute name are extracted from the business data records. The attribute names are replaced according to the Chinese names of the business attribute set records. Finally, the business data with the agreed Chinese names is returned as the query result.

7. The method for constructing a three-dimensional scene for BIM digital application in highway engineering according to claim 1, characterized in that, The specific method for step (11) is as follows: By using the SDK provided by the Ceisum platform or the SuperMap iClient3D platform, BIM model services and terrain model services can be retrieved and integrated into digital applications to form a 3D base map scene that supports business applications.

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