Terrain modeling method and device based on domestic three-dimensional graphic platform Railworks

Abstract

The invention relates to the technical field of three-dimensional modeling, in particular to a terrain modeling method and device based on a domestic three-dimensional graphic platform Railworks, and the method comprises the steps: collecting terrain data along a rail transit engineering project, and generating a structured original data pool; the method comprises the following steps: extracting and processing a discrete three-dimensional point set through a Railworks platform, and generating a triangular mesh by adopting a Gift Wrapping algorithm and a Delaunay triangulation algorithm; reconstructing a three-dimensional terrain surface model, adding an attribute database, and integrating elevation and gradient attributes according to industrial standards; and a downstream bridge and roadbed design module is connected through a data synchronization mechanism, so that design parameters are automatically updated. The device correspondingly realizes functions of each step. According to the method, the problems of high data security risk and low collaboration efficiency caused by dependence on foreign software are solved, an autonomous solution is provided, and the data processing security and the cross-professional design collaboration efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of 3D modeling technology, and in particular to a terrain modeling method and apparatus based on the domestic 3D graphics platform Railworks. Background Technology

[0002] BIM (Building Information Modeling) is a construction engineering method based on three-dimensional digital models. Its core lies in constructing a building information model that includes geometric information and physical, functional, and other attribute parameters. The modeling process begins with parametric design. Components are not only presented in three-dimensional form but are also interconnected through inherent logical relationships, allowing modifications to one element to automatically coordinate and update all related parts. The model gradually integrates information from multiple disciplines, including architecture, structure, and mechanical and electrical systems, forming a unified central database.

[0003] Existing BIM modeling technologies suffer from the following pain points: Specifically, in the process of modeling terrain for rail transit, the heavy reliance on foreign BIM software platforms such as Revit and Bentley means that data processing may involve overseas servers or non-self-controlled environments, posing a potential risk of leakage to highly secure surveying and mapping data. Simultaneously, industry-standard software such as ArcGIS and EVS are primarily developed for mining or oil reservoir applications, with functional designs significantly different from the needs of rail transit professionals. The lack of customized data transfer interfaces means that terrain models are often limited to visual presentation and cannot achieve seamless collaboration with downstream design professionals. For example, in bridge design applications, terrain data needs to provide real-time elevation information to support abutment elevation calculations. However, foreign software platforms lack dedicated integration mechanisms, requiring designers to manually export and import data, increasing operational complexity and easily leading to data inconsistencies, severely hindering overall design efficiency. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a terrain modeling method and apparatus based on the domestic 3D graphics platform Railworks, which solves the technical problems of high terrain data security risks and low efficiency of downstream professional design collaboration caused by reliance on foreign BIM software and differences in industry functions.

[0005] To solve the above-mentioned technical problems, the specific contents of the present invention are as follows: In a first aspect, the terrain modeling method based on the domestic 3D graphics platform Railworks provided by this invention includes: Step 1: Collect topographic data along the rail transit project route. The topographic data includes control points, elevations, slopes, and ground feature information obtained by surveying equipment, as well as dwg format topographic map files and digital elevation model (DEM) data processed by AutoCAD. Perform layer standardization on the dwg format topographic map files, separating elevation points and contour lines into different layers to generate a structured raw data pool including the topographic data. Step 2: Extract discrete 3D point sets from the structured raw data pool through the data interface of the Railworks platform, filter invalid data points, and generate an initial 3D point set set; Step 3: Preprocess the initial three-dimensional point set, remove points with duplicate spatial coordinates, and project the preprocessed three-dimensional point set onto a two-dimensional plane, retaining the X and Y coordinates to form a two-dimensional point set sequence; Step 4: Mesh the two-dimensional point set sequence, use the Gift Wrapping algorithm to calculate the convex hull boundary of the point set, and then use the Delaunay triangulation algorithm to generate a triangular mesh within the convex hull, outputting a two-dimensional triangular mesh. Step 5: Associate the vertices of the two-dimensional triangular mesh with the Z coordinates in the initial three-dimensional point set to generate a three-dimensional triangular mesh with elevation information, and reconstruct the three-dimensional terrain surface model using the Railworks platform. Step 6: Add an attribute database to the three-dimensional terrain surface model. The attribute database integrates elevation and slope attributes according to the rail transit industry delivery standards. Step 7: Connect the 3D terrain surface model with the attribute database to the downstream bridge and roadbed design modules through the data synchronization mechanism of the Railworks platform; when the 3D terrain surface model changes, the design parameters in the downstream design modules are automatically updated through database triggers.

[0006] Furthermore, in the terrain modeling method based on the domestic 3D graphics platform Railworks described in this invention, step 1 includes: Control points and elevation information are obtained using a total station, and the coordinates and slope data of ground features are obtained using satellite positioning equipment. Receive DWG format topographic map files, identify the layer structure in the file, assign elevation points to elevation point layers, and assign contour lines to contour line layers; Analyze digital elevation model (DEM) data, extract elevation values ​​of grid points, and generate point set coordinate information; The control points, elevation information, feature coordinates, slope data, elevation point layers, contour line layers, and point set coordinate information are integrated to form the structured raw data pool.

[0007] Furthermore, in the terrain modeling method based on the domestic 3D graphics platform Railworks described in this invention, step 2 includes: Read the elevation point layer and contour line layer of the dwg file from the structured raw data pool, and extract the coordinates of discrete points in the layers; Read the digital elevation model (DEM) data from the structured raw data pool and convert the grid nodes into three-dimensional coordinate points; The extracted discrete point coordinates and 3D coordinates are verified for their range. Abnormal points that exceed the preset coordinate range are deleted, and the verified point coordinates are integrated into the initial 3D point set.

[0008] Furthermore, in the terrain modeling method based on the domestic 3D graphics platform Railworks described in this invention, step 3 includes: The initial set of three-dimensional points is traversed to identify points with identical X and Y coordinates. The first point to appear is retained, and subsequent duplicate points are deleted. The deduplicated 3D point set is projected onto a 2D plane, retaining the X and Y coordinates, and the Z coordinate is stored as an elevation attribute. The projected two-dimensional points are arranged in coordinate order to form the two-dimensional point set sequence.

[0009] Furthermore, in the terrain modeling method based on the domestic 3D graphics platform Railworks described in this invention, step 4 of meshing the 2D point set sequence includes: The Gift Wrapping algorithm is used to process the two-dimensional point set sequence. The lowest point in the point set is selected as the starting point, and the point set is traversed in ascending order of polar angle to determine the convex hull boundary vertices. A convex hull boundary is established based on the vertices of the convex hull boundary. Within the convex hull boundary, the Delaunay triangulation algorithm is executed to generate a triangular mesh, which satisfies the empty circle rule. For triangular meshes that satisfy the empty circle rule, a divide-and-conquer strategy is adopted for strip terrain data to divide the point set into multiple sub-regions for parallel triangulation processing. The triangulation results of multiple sub-regions are subjected to boundary fusion processing to output the two-dimensional triangular mesh.

[0010] Furthermore, in the terrain modeling method based on the domestic 3D graphics platform Railworks described in this invention, step 5 of reconstructing the 3D terrain surface model includes: Establish a mapping relationship between the vertex indices of the two-dimensional triangular mesh and the Z coordinates in the initial three-dimensional point set; Match the corresponding elevation value by vertex number, and assign the matched elevation value to the vertex of the two-dimensional triangular mesh; The Railworks platform was used to convert a 3D triangular mesh with elevation data into a continuous 3D terrain surface model.

[0011] Furthermore, in the terrain modeling method based on the domestic 3D graphics platform Railworks described in this invention, the additional attribute database in step 6 includes: In accordance with the delivery standards of the rail transit industry, elevation and slope attribute fields are added to the three-dimensional terrain surface model; Establish the association between the attribute database and the 3D terrain surface model, and store elevation and slope values; Configure the data access interface to query the corresponding elevation and slope attribute values ​​by vertex coordinates.

[0012] Furthermore, in the terrain modeling method based on the domestic 3D graphics platform Railworks described in this invention, the data synchronization mechanism in step 7 includes: Establish a data association table between the three-dimensional terrain surface model and the downstream bridge design and roadbed design; Configure database triggers to monitor changes in elevation attributes and geometric parameters of the 3D terrain surface model; When a data change is detected, the abutment elevation parameters in the downstream bridge design and the slope parameters in the roadbed design are updated through a data synchronization mechanism.

[0013] Furthermore, the terrain modeling method based on the domestic 3D graphics platform Railworks described in this invention also includes: When performing step 4, the granularity of sub-region division is dynamically adjusted according to the point set density; When performing step 7, a version management mechanism is established to record the historical changes of the 3D terrain surface model.

[0014] Secondly, the terrain modeling device based on the domestic 3D graphics platform Railworks provided by the present invention is applied to the terrain modeling method based on the domestic 3D graphics platform Railworks as described above, including: The data acquisition module is configured to collect topographic data along the rail transit engineering project. The topographic data includes control points, elevations, slopes, and ground feature information obtained by surveying equipment, as well as dwg format topographic map files and digital elevation model (DEM) data processed by AutoCAD. Layer standardization is performed on the dwg format topographic map files to separate elevation points and contour lines to different layers, generating a structured raw data pool that includes the topographic data. The point set extraction module is configured to extract discrete 3D point sets from the structured raw data pool through the data interface of the Railworks platform, filter invalid data points, and generate an initial 3D point set set. The preprocessing component is configured to preprocess the initial set of three-dimensional points, remove points with duplicate spatial coordinates, and project the preprocessed set of three-dimensional points onto a two-dimensional plane, retaining the X and Y coordinates to form a sequence of two-dimensional points. The meshing module is configured to perform meshing on the two-dimensional point set sequence, calculate the convex hull boundary of the point set using the Gift Wrapping algorithm, and then generate a triangular mesh within the convex hull using the Delaunay triangulation algorithm, outputting a two-dimensional triangular mesh. The model reconstruction module is configured to associate the vertices of the two-dimensional triangular mesh with the Z coordinates in the initial three-dimensional point set to generate a three-dimensional triangular mesh with elevation information, and to reconstruct a three-dimensional terrain surface model using the Railworks platform. An attribute attachment module is configured to attach an attribute database to the three-dimensional terrain surface model, the attribute database integrating elevation and slope attributes according to rail transit industry delivery standards. The data synchronization module is configured to connect the 3D terrain surface model with the attribute database to the downstream bridge and roadbed design modules through the data synchronization mechanism of the Railworks platform; when the 3D terrain surface model changes, the design parameters in the downstream design modules are automatically updated through database triggers.

[0015] Beneficial effects of this invention; This invention relates to a terrain modeling method and apparatus based on the domestically developed 3D graphics platform Railworks. By integrating multi-source terrain data acquisition, efficient geometric processing algorithms, and attribute database integration, it optimizes the entire process of terrain model creation and application. Using a domestic platform to process all terrain data ensures data processing operates in an autonomous and controllable environment, avoiding interference from overseas servers and reducing the risk of terrain data leakage at the source. Elevation and slope attribute fields are customized according to rail transit industry delivery standards, enhancing the model's professional applicability and resolving the mismatch between industry-standard software functions and rail transit requirements. Through data synchronization mechanisms and database triggers, downstream design parameters are automatically updated, achieving deep collaboration between the terrain model and bridge and roadbed designs, reducing manual operations and improving design efficiency and data consistency. The overall method fully leverages the advantages of domestic technology, solving the technical problems of high data security risks and low efficiency in downstream professional design collaboration caused by reliance on foreign BIM software. Attached Figure Description

[0016] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating the process and algorithm of the present invention. Figure 2 This invention enables the rapid creation of functional maps of terrain. Figure 3 Generate a terrain model rendering of the terrain data for this invention; Figure 4 This is a diagram illustrating the terrain elevation query auxiliary function of the present invention. Figure 5 This is a functional diagram of topographic measurement according to the present invention; Figure 6 This is a diagram illustrating the visualization, transmission, and application of terrain data according to the present invention. Figure 7 This is a schematic diagram of point set reading according to the present invention; Figure 8 This is a schematic diagram of point set dimensionality reduction according to the present invention; Figure 9 This is a schematic diagram of point set triangulation according to the present invention; Figure 10 This is a schematic diagram of the point set dimensionality upgrade of the present invention. Detailed Implementation

[0018] To make the technical solution of the present invention clearer, the present invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The present invention provided by various embodiments will be described in detail below with reference to the accompanying drawings. To better understand the purpose of the present invention, the present invention will be described in further detail below.

[0019] Firstly, please refer to Figures 1 to 10 The terrain modeling method based on the domestic 3D graphics platform Railworks provided by this invention includes: Step 1: Collect topographic data along the rail transit project route. The topographic data includes control points, elevations, slopes, and ground feature information obtained by surveying equipment, as well as dwg format topographic map files and digital elevation model (DEM) data processed by AutoCAD. Perform layer standardization on the dwg format topographic map files, separating elevation points and contour lines into different layers to generate a structured raw data pool including the topographic data. Step 2: Extract discrete 3D point sets from the structured raw data pool through the data interface of the Railworks platform, filter invalid data points, and generate an initial 3D point set set; Step 3: Preprocess the initial three-dimensional point set, remove points with duplicate spatial coordinates, and project the preprocessed three-dimensional point set onto a two-dimensional plane, retaining the X and Y coordinates to form a two-dimensional point set sequence; Step 4: Mesh the two-dimensional point set sequence, use the Gift Wrapping algorithm to calculate the convex hull boundary of the point set, and then use the Delaunay triangulation algorithm to generate a triangular mesh within the convex hull, outputting a two-dimensional triangular mesh. Step 5: Associate the vertices of the two-dimensional triangular mesh with the Z coordinates in the initial three-dimensional point set to generate a three-dimensional triangular mesh with elevation information, and reconstruct the three-dimensional terrain surface model using the Railworks platform. Step 6: Add an attribute database to the three-dimensional terrain surface model. The attribute database integrates elevation and slope attributes according to the rail transit industry delivery standards. Step 7: Connect the 3D terrain surface model with the attribute database to the downstream bridge and roadbed design modules through the data synchronization mechanism of the Railworks platform; when the 3D terrain surface model changes, the design parameters in the downstream design modules are automatically updated through database triggers.

[0020] The terrain modeling method based on the domestic 3D graphics platform Railworks involves the entire process from terrain data acquisition to 3D model generation and downstream collaboration. The method begins with comprehensive terrain data acquisition. The terrain data along the rail transit project route comes from various surveying devices, including control points and elevation information obtained from total stations, and feature coordinates and slope data obtained from satellite positioning equipment. It also integrates DWG format topographic map files processed by AutoCAD and Digital Elevation Model (DEM) data. Layer standardization is performed on the DWG format topographic map files, identifying the layer structure within the file, assigning elevation points to elevation point layers, and contour lines to contour line layers. The DEM data is parsed to extract the elevation values ​​of grid points, generating point set coordinate information, and finally integrating all the terrain data into a structured raw data pool. This step provides a unified and standardized data source for subsequent point set processing, avoiding processing obstacles caused by inconsistent data formats.

[0021] Discrete 3D point sets are extracted from the structured raw data pool using the Railworks platform's data interface. This includes reading the elevation point and contour line layers from DWG files to extract discrete point coordinates, and reading DEM data to convert grid nodes into 3D coordinate points. The extracted point coordinates are then validated for their range, and outliers exceeding the preset range are removed, generating an initial 3D point set. This step ensures the validity and integrity of the point set data, laying the foundation for subsequent geometric processing.

[0022] The initial 3D point set is preprocessed by traversing the set to identify points with identical X and Y coordinates, retaining the first occurrence and deleting subsequent duplicates to achieve spatial coordinate deduplication. The deduplicated 3D point set is then projected onto a 2D plane, retaining the X and Y coordinates while storing the Z coordinate as an elevation attribute, forming a 2D point set sequence. This preprocessing eliminates data redundancy and reduces the computational complexity of subsequent mesh generation.

[0023] A 2D point set sequence is meshed. The Gift Wrapping algorithm is used to calculate the convex hull boundary of the point set. The lowest point in the point set is selected as the starting point, and the point set is traversed in ascending order of polar angle to determine the vertices of the convex hull boundary, thus establishing the convex hull boundary. Within the convex hull boundary, the Delaunay triangulation algorithm is executed to generate triangular meshes that satisfy the empty circle rule, ensuring mesh quality. For large point sets of strip terrain data, a divide-and-conquer strategy is used to divide the point set into multiple sub-regions for parallel triangulation processing. The results of the sub-regions are then merged to output a 2D triangular mesh. This step achieves efficient triangulation of the point set, providing a geometric foundation for 3D model reconstruction.

[0024] The vertices of the 2D triangular mesh are associated with the Z-coordinates of the initial 3D point set, establishing a mapping relationship between vertex indices and Z-coordinates. The corresponding elevation values ​​are matched using vertex numbers and assigned to the vertices of the 2D triangular mesh, generating a 3D triangular mesh with elevation information. The Railworks platform is then used to transform the 3D triangular mesh into a continuous 3D terrain surface model, completing the terrain geometry reconstruction.

[0025] An attribute database is added to the 3D terrain surface model. Based on rail transit industry delivery standards, elevation and slope attribute fields are added, establishing a link between the attribute database and the model, and storing elevation and slope values. A data access interface is configured to support querying corresponding elevation and slope attribute values ​​by vertex coordinates, enhancing the model's data accessibility.

[0026] A 3D terrain surface model with an attribute database is connected to downstream bridge and roadbed design modules via the Railworks platform's data synchronization mechanism, establishing a data association table between the model and downstream designs. Database triggers are set to monitor changes in the elevation attributes and geometric parameters of the 3D terrain surface model. When a data change is detected, the abutment elevation parameters in the downstream bridge design and the slope parameters in the roadbed design are automatically updated. This step achieves deep collaboration between the terrain model and professional designs, improving design efficiency and data consistency.

[0027] The various steps in this invention are logically interconnected, forming a closed-loop process from data standardization and processing to geometric model generation, attribute integration, and downstream synchronization. Data acquisition and structuring ensure input quality, point set extraction and preprocessing optimize data preparation, mesh generation and model reconstruction enable terrain visualization, and attribute appending and data synchronization expand the value for engineering applications. Through integration with the Railworks platform, the method fully leverages the advantages of domestic technology, addressing issues of data security and professional collaboration.

[0028] In step 1, control points and elevation information are acquired using a total station, and feature coordinates and slope data are acquired using satellite positioning equipment, covering multiple sources of terrain data. After receiving the DWG format topographic map file, the layer structure in the file is identified, and elevation points are assigned to the elevation point layer, and contour lines are assigned to the contour line layer, completing the layer standardization process. The digital elevation model (DEM) data is parsed, and the elevation values ​​of grid points are extracted to generate point set coordinate information. Finally, control points, elevation information, feature coordinates, slope data, elevation point layers, contour line layers, and point set coordinate information are integrated to form a structured raw data pool. The logical relationship in step 1 is that multi-source data acquisition and standardization processing build a unified data foundation, directly supporting the data interface extraction in step 2 and avoiding data format inconsistency issues.

[0029] Step 2 reads the elevation point layer and contour line layer from the structured raw data pool (DWG file), extracts the coordinates of discrete points in the layers, and simultaneously reads the digital elevation model (DEM) data, converting grid nodes into 3D coordinate points. The extracted discrete point coordinates and 3D coordinate points are then validated for their ranges, and outliers exceeding the preset range are removed. The validated point coordinates are then integrated into an initial 3D point set. The logical relationship of Step 2 is that the data extraction and validation process generates a clean initial point set, laying the foundation for the preprocessing steps in Step 3 and improving data quality.

[0030] Step 3 iterates through the initial 3D point set, identifying points with identical X and Y coordinates, retaining the first occurrence of each point, and deleting subsequent duplicates to achieve spatial coordinate deduplication. The deduplicated 3D point set is then projected onto a 2D plane, retaining the X and Y coordinates, and storing the Z coordinate as an elevation attribute. The projected 2D points are then arranged in coordinate order to form a 2D point set sequence. The logical relationship of Step 3 is that, through deduplication and projection operations, data redundancy is eliminated, computational complexity is reduced, and an optimized 2D point sequence is provided for mesh generation in Step 4.

[0031] Step 4 involves meshing the 2D point set sequence using the Gift Wrapping algorithm. The lowest point in the set is selected as the starting point, and the point set is traversed in ascending order of polar angle to determine the convex hull boundary vertices. A convex hull boundary is established based on these vertices, and the Delaunay triangulation algorithm is executed within this boundary to generate a triangular mesh that satisfies the empty circle rule. For strip-shaped terrain data, a divide-and-conquer strategy is used to divide the point set into multiple sub-regions for parallel triangulation. The triangulation results from these sub-regions are then fused to output a 2D triangular mesh. The logical relationship of Step 4 is that the convex hull boundary calculation and Delaunay triangulation ensure mesh quality, while the divide-and-conquer strategy improves processing efficiency under large data volumes, providing the geometric foundation for the 3D model reconstruction in Step 5.

[0032] This invention establishes a mapping relationship between the vertex indices of a 2D triangular mesh and the Z-coordinates in an initial 3D point set. Specifically, this mapping is achieved by creating a correspondence table between a vertex number list and an elevation value array. The vertex numbers are generated based on the vertex order of the 2D triangular mesh, while the elevation value array originates from the Z-coordinate data stored in the initial 3D point set. By matching the vertex numbers with the corresponding elevation values, a traversal query method is used to align each vertex number with its index position in the elevation value array, ensuring that the elevation values ​​are accurately assigned to the 2D triangular mesh vertices. The elevation-integrated 3D triangular mesh is transformed into a continuous 3D terrain surface model using the Railworks platform. The built-in mesh rendering interface of the Railworks platform is called, and the vertex coordinates and connectivity of the 3D triangular mesh are input into the platform's geometry engine. A smooth 3D terrain surface model is generated through a surface fitting algorithm, completing the terrain geometry reconstruction. The above steps are logically interconnected. The established mapping relationship provides the foundation for elevation matching, elevation matching ensures the accuracy of the geometric data, and the platform transformation ultimately enables model visualization. Each step is sequentially dependent, forming a complete model reconstruction process.

[0033] This invention includes adding elevation and slope attribute fields to a 3D terrain surface model according to rail transit industry delivery standards. Specifically, it involves defining a database table structure, storing vertex elevation values ​​in the elevation attribute field, and calculating and storing the slope angle values ​​of adjacent triangular faces in the slope attribute field. It establishes a relationship between the attribute database and the 3D terrain surface model, using vertex coordinates as the primary key to link database records with the model's geometric vertices, storing elevation and slope values ​​in a relational database table. A data access interface is configured to query the corresponding elevation and slope attribute values ​​using vertex coordinates, enabling coordinate-based SQL queries or API calls, supporting real-time data retrieval. The above steps are logically clear, with standardized attribute storage for field additions, established relationships ensuring data consistency, and a data access interface providing application support. Each step is progressive, enhancing the model's data integration capabilities.

[0034] This invention includes establishing a data association table between a 3D terrain surface model and downstream bridge and roadbed designs. Specifically, it records the correspondence between model vertex IDs and downstream design parameter IDs by creating a many-to-many association table. Database triggers are set to monitor changes in the elevation attributes and geometric parameters of the 3D terrain surface model. Trigger scripts are written in the database system to listen for update events of elevation attribute fields and geometric coordinates. When a data change is detected, the abutment elevation parameters in the downstream bridge design and the slope parameters in the roadbed design are updated through a data synchronization mechanism. An event-driven approach automatically calls the update interface of the downstream modules, pushing the changed data to the bridge and roadbed design modules. The above steps are logically coherent. The association table establishes the foundation for data links, triggers enable real-time monitoring, and the synchronization mechanism ensures data collaboration. Each step is interconnected, improving design efficiency and data consistency.

[0035] This invention includes step 4, which dynamically adjusts the sub-region division granularity based on the point set density. Specifically, this is achieved by calculating the spatial distribution density of points in the two-dimensional point set sequence and employing a density threshold judgment mechanism. When the point set density is higher than a preset threshold, the sub-region division granularity is reduced to improve processing accuracy; when the point set density is lower than the preset threshold, the sub-region division granularity is increased to optimize computational efficiency. Step 7 involves establishing a version management mechanism to record the historical change records of the 3D terrain surface model. A version control system is used to store the model change sequence, and a version snapshot is generated each time the data is updated, recording the change time, change content, and user information. The above steps are logically complementary, dynamically adjusting and optimizing mesh generation performance. Version management ensures data traceability, and the steps work collaboratively to enhance the adaptability and reliability of the method.

[0036] Secondly, the terrain modeling device based on the domestic 3D graphics platform Railworks provided by the present invention is applied to the terrain modeling method based on the domestic 3D graphics platform Railworks as described above, including: The data acquisition module is configured to collect topographic data along the rail transit engineering project. The topographic data includes control points, elevations, slopes, and ground feature information obtained by surveying equipment, as well as dwg format topographic map files and digital elevation model (DEM) data processed by AutoCAD. Layer standardization is performed on the dwg format topographic map files to separate elevation points and contour lines to different layers, generating a structured raw data pool that includes the topographic data. The point set extraction module is configured to extract discrete 3D point sets from the structured raw data pool through the data interface of the Railworks platform, filter invalid data points, and generate an initial 3D point set set. The preprocessing component is configured to preprocess the initial set of three-dimensional points, remove points with duplicate spatial coordinates, and project the preprocessed set of three-dimensional points onto a two-dimensional plane, retaining the X and Y coordinates to form a sequence of two-dimensional points. The meshing module is configured to perform meshing on the two-dimensional point set sequence, calculate the convex hull boundary of the point set using the Gift Wrapping algorithm, and then generate a triangular mesh within the convex hull using the Delaunay triangulation algorithm, outputting a two-dimensional triangular mesh. The model reconstruction module is configured to associate the vertices of the two-dimensional triangular mesh with the Z coordinates in the initial three-dimensional point set to generate a three-dimensional triangular mesh with elevation information, and to reconstruct a three-dimensional terrain surface model using the Railworks platform. An attribute attachment module is configured to attach an attribute database to the three-dimensional terrain surface model, the attribute database integrating elevation and slope attributes according to rail transit industry delivery standards. The data synchronization module is configured to connect the 3D terrain surface model with the attribute database to the downstream bridge and roadbed design modules through the data synchronization mechanism of the Railworks platform; when the 3D terrain surface model changes, the design parameters in the downstream design modules are automatically updated through database triggers.

[0037] This invention, based on the domestically developed 3D graphics platform Railworks, addresses long-standing technical pain points in the field of rail transit engineering. These include high risks to terrain data security due to reliance on foreign BIM software, mismatch between the functions of general industry software and the specific needs of rail transit, and the inability of terrain models to efficiently collaborate with downstream design teams. This invention provides an independent solution. By integrating multi-source terrain data acquisition, efficient geometric processing algorithms, and attribute database integration, this invention optimizes the entire process of terrain model creation and application.

[0038] During the terrain data acquisition phase, control points and elevation information were acquired using a total station, and feature coordinates and slope data were obtained using satellite positioning equipment. Simultaneously, DWG format topographic map files and Digital Elevation Model (DEM) data processed by AutoCAD were received. Layer standardization was performed on the DWG format topographic map files, identifying the layer structure within the file, assigning elevation points to elevation point layers, and contour lines to contour line layers. The DEM data was parsed to extract the elevation values ​​of grid points, generating point set coordinate information. All data was integrated to form a structured raw data pool, providing a unified data foundation for subsequent processing.

[0039] Discrete 3D point sets are extracted from the structured raw data pool via the Railworks platform's data interface. This includes reading the elevation point and contour line layers from DWG files to extract discrete point coordinates, and reading DEM data to convert grid nodes into 3D coordinate points. The extracted point coordinates are then validated for their range, and outliers exceeding the preset coordinate range are removed, generating an initial 3D point set.

[0040] The initial 3D point set is preprocessed by traversing the set to identify points with identical X and Y coordinates. The first occurrence of each point is retained, and subsequent duplicates are removed, thus deduplicating spatial coordinates. The deduplicated 3D point set is then projected onto a 2D plane, retaining the X and Y coordinates while storing the Z coordinate as an elevation attribute, forming a 2D point set sequence. This step eliminates data redundancy and reduces computational complexity.

[0041] A 2D point set sequence is meshed. The Gift Wrapping algorithm is used to calculate the convex hull boundary of the point set. The lowest point in the point set is selected as the starting point, and the point set is traversed in ascending order of polar angle to determine the vertices of the convex hull boundary, thus establishing the convex hull boundary. Within the convex hull boundary, the Delaunay triangulation algorithm is executed to generate triangular meshes that satisfy the empty circle rule, ensuring mesh quality. For large point sets of strip terrain data, a divide-and-conquer strategy is used to divide the point set into multiple sub-regions for parallel triangulation processing. The sub-region results are then fused to output a 2D triangular mesh. The granularity of the sub-region division is dynamically adjusted according to the point set density to optimize processing efficiency.

[0042] The vertices of the 2D triangular mesh are associated with the Z-coordinates of the initial 3D point set, establishing a mapping relationship between vertex indices and Z-coordinates. The corresponding elevation values ​​are matched using vertex numbers and assigned to the vertices of the 2D triangular mesh, generating a 3D triangular mesh with elevation information. The Railworks platform is then used to transform the 3D triangular mesh into a continuous 3D terrain surface model, completing the terrain geometry reconstruction.

[0043] An attribute database is added to the 3D terrain surface model. Based on rail transit industry delivery standards, elevation and slope attribute fields are added, establishing a link between the attribute database and the 3D terrain surface model, storing elevation and slope values. A data access interface is configured to allow querying corresponding elevation and slope attribute values ​​via vertex coordinates, enhancing the model's data accessibility.

[0044] A 3D terrain surface model with an attribute database is connected to downstream bridge and roadbed design modules via the Railworks platform's data synchronization mechanism, establishing a data association table between the 3D terrain surface model and the downstream designs. Database triggers are configured to monitor changes in the elevation attribute and geometric parameters of the 3D terrain surface model. When a data change is detected, the abutment elevation parameters in the downstream bridge design and the slope parameters in the roadbed design are automatically updated. A version management mechanism is established to record the historical change history of the 3D terrain surface model, ensuring data traceability.

[0045] This invention achieves secure processing, efficient modeling, and downstream collaboration of terrain data through the aforementioned steps, supporting the overall efficiency and data consistency of rail transit engineering design. Based on the integration of the domestically developed 3D graphics platform Railworks, the method fully leverages its independent advantages to solve specific industry needs and data transmission challenges.

[0046] Embodiment 1 of the present invention: Application of terrain modeling in bridge design scenarios; In the design of rail transit bridges, the elevation information of topographic data is directly related to determining the elevation of the bridge substructure abutments. This embodiment uses a railway bridge project as an application scenario, and the specific implementation method is as follows. First, topographic data along the bridge route is collected, including control points and elevation information obtained through a total station, and feature coordinates and slope data obtained through satellite positioning equipment. Simultaneously, DWG format topographic map files processed by AutoCAD and Digital Elevation Model (DEM) data are received. Layer standardization is performed on the DWG files, assigning elevation points to an elevation point layer and contour lines to a contour line layer. The DEM data is parsed to extract the elevation values ​​of grid points, generating point set coordinate information, and integrating them to form a structured raw data pool. This step provides a unified data source for bridge design, avoiding inconsistencies in multi-source data formats.

[0047] Discrete 3D point sets are extracted from the structured raw data pool using the Railworks platform's data interface. This includes reading elevation and contour layers from DWG files to extract discrete point coordinates, and reading DEM data to convert grid nodes into 3D coordinate points. The extracted point coordinates are then validated for range, outliers are removed, and an initial 3D point set is generated.

[0048] The initial 3D point set is preprocessed by traversing the set to identify points with identical X and Y coordinates. The first occurrence of each point is retained, and duplicate points are removed, thus achieving spatial coordinate deduplication. The deduplicated 3D point set is then projected onto a 2D plane, retaining the X and Y coordinates while storing the Z coordinate as an elevation attribute, forming a 2D point set sequence.

[0049] A two-dimensional point set sequence is meshed. The Gift Wrapping algorithm is used to calculate the convex hull boundary of the point set. The lowest point in the point set is selected as the starting point, and the point set is traversed in polar angle order to determine the vertices of the convex hull boundary, thus establishing the convex hull boundary. Within the convex hull, the Delaunay triangulation algorithm is executed to generate a triangular mesh that satisfies the empty circle rule. For the strip terrain data along the bridge, a divide-and-conquer strategy is used to divide the point set into multiple sub-regions for parallel processing. The results of the sub-regions are then merged to output a two-dimensional triangular mesh. The granularity of the sub-region division is dynamically adjusted according to the point set density to improve processing efficiency.

[0050] The vertices of the 2D triangular mesh are associated with the Z-coordinates of the initial 3D point set, establishing a mapping relationship between vertex indices and Z-coordinates. Elevation values ​​are matched by vertex numbers and assigned to the vertices of the 2D triangular mesh, generating a 3D triangular mesh with elevation information. The 3D triangular mesh is then transformed into a continuous 3D terrain surface model using the Railworks platform.

[0051] An attribute database is added to the 3D terrain surface model. Elevation and slope attribute fields are added according to rail transit industry delivery standards. The relationship between the attribute database and the model is established, storing elevation and slope values. A data access interface is configured to support querying elevation and slope attribute values ​​by vertex coordinates.

[0052] A 3D terrain surface model with an attribute database is connected to the bridge design module via the Railworks platform's data synchronization mechanism, establishing a data association table between the model and the bridge design. Database triggers are set to monitor changes in the terrain model's elevation attributes; when a data change is detected, the abutment elevation parameters in the bridge design are automatically updated. A version management mechanism is established to record historical model changes, ensuring data traceability. This embodiment achieves deep collaboration between terrain data and bridge design through the above steps, solving the technical problem of using elevation data to support abutment elevation calculation.

[0053] Embodiment 2 of the present invention: Application of terrain modeling in roadbed design scenarios; In the design of rail transit subgrades, terrain slope information directly affects the design of subgrade slopes and earthwork calculations. This embodiment uses a railway subgrade project as an application scenario, and the specific implementation method is as follows. During the terrain data acquisition stage, control points, elevations, slopes, and ground feature information are acquired using a total station and satellite positioning equipment, while simultaneously processing DWG format topographic map files and DEM data. Layer standardization is performed on the DWG files, separating elevation points and contour lines into independent layers. The DEM data is parsed to generate point set coordinate information, which is then integrated into a structured raw data pool.

[0054] Discrete 3D point sets are extracted from the structured raw data pool. Layer data and DEM data from DWG files are read through the Railworks platform data interface. After verifying the coordinate range, an initial 3D point set is generated. In the preprocessing stage, duplicate points are removed and projected onto a 2D plane to form a 2D point set sequence.

[0055] In the mesh generation stage, the Gift Wrapping algorithm and the Delaunay triangulation algorithm are used to generate triangular meshes. For the strip terrain of the roadbed, a divide-and-conquer strategy is used for parallel processing to output a two-dimensional triangular mesh. The vertices of the two-dimensional mesh are associated with the initial Z coordinates to generate a three-dimensional triangular mesh with elevation, and the three-dimensional terrain surface model is reconstructed using the Railworks platform.

[0056] An attribute database is added to the model, including elevation and slope attribute fields, and data relationships are established. Slope queries are supported through a data access interface, providing slope parameters for roadbed design.

[0057] The model and roadbed design module are connected via a data synchronization mechanism. Triggers are set to monitor changes in slope attributes and automatically update slope parameters in the roadbed design. A version management mechanism records change history, improving design consistency. This embodiment solves the technical problem of slope design relying on terrain data by synchronizing terrain slope data with roadbed design in real time.

[0058] This invention, based on the domestically developed 3D graphics platform Railworks, addresses the high security risks of terrain data and low efficiency in downstream professional design collaboration caused by reliance on foreign BIM software and differences in industry functions through multiple technical measures. The method first utilizes the domestically developed Railworks platform to process all terrain data, ensuring data operation in an independently controllable environment and avoiding intervention from overseas servers, thus eliminating the risk of data leakage at the source. During the data acquisition phase, multi-source terrain information is integrated, including control points, elevations, slopes, and feature data obtained through total stations and satellite positioning equipment, as well as DWG format topographic map files and Digital Elevation Model (DEM) data processed by AutoCAD. Layer standardization is performed on the DWG files, separating elevation points and contour lines into independent layers to generate a structured raw data pool, achieving data format unification and preprocessing, and reducing dependence on foreign software.

[0059] Discrete 3D point sets are extracted through the Railworks platform's data interface, and invalid data points are filtered to generate an initial 3D point set. Subsequently, the Gift Wrapping algorithm is used to calculate the convex hull boundary of the point set, and the Delaunay triangulation algorithm is used to generate a triangular mesh. All algorithms are executed within a domestic platform, ensuring data processing security and efficiency. For the needs of the rail transit industry, the method adds an attribute database to the 3D terrain surface model, integrates elevation and slope attributes according to industry delivery standards, configures a data access interface to support real-time querying, resolves the issue of incompatibility with general software functions, and provides customized application support.

[0060] The data synchronization mechanism connects the 3D terrain surface model with an attribute database to downstream bridge and roadbed design modules via the Railworks platform. Database triggers are set to monitor model changes and automatically update downstream design parameters, such as abutment elevation and slope parameters, enabling cross-disciplinary design collaboration, reducing manual operations, and improving data consistency and design efficiency. The overall approach effectively addresses data security and collaboration challenges through integration with domestic platforms, algorithm optimization, and automated synchronization.

[0061] The technical terms used in this invention are explained below; The Gift Wrapping algorithm, also known as the Gift Wrapping algorithm, is an algorithm for calculating the convex hull boundary of a point set. In this invention, the Gift Wrapping algorithm processes a sequence of two-dimensional point sets. It selects the lowest point in the point set as the starting point, traverses the point set in ascending order of polar angle, determines the vertices of the convex hull boundary, and thus establishes the convex hull boundary. This provides a geometric constraint basis for subsequent triangulation, ensuring that all points are located inside or on the boundary of the convex polygon, thereby improving data processing efficiency and accuracy.

[0062] The Delaunay triangulation algorithm, also known as the Delaunay triangulation algorithm, is an algorithm for generating triangular meshes that follows the empty circle rule. In this invention, the algorithm is executed within the convex hull boundary. Based on the convex hull vertices determined by the Gift Wrapping algorithm, it generates triangular meshes where the circumcircle of each triangle does not contain other points, ensuring optimal mesh quality, supporting smooth reconstruction of terrain surfaces, and providing a high-quality geometric foundation for 3D models.

[0063] Divide and conquer is a parallel computing method for processing large-scale data. In this invention, the divide and conquer algorithm is designed for large point sets of strip terrain data. It divides the point set into multiple sub-regions for parallel triangulation. Each sub-region independently executes the Delaunay triangulation algorithm. Then, the sub-region results are processed by boundary fusion to eliminate seam problems and output a complete two-dimensional triangular mesh, thereby optimizing computational efficiency and adapting to the long strip terrain features in rail transit engineering.

[0064] The construction of a 3D terrain surface model begins with the association process between the vertices of a 2D triangular mesh and the Z-coordinates of the initial 3D point set. A mapping relationship between the vertex indices and Z-coordinates of the 2D triangular mesh is established. The corresponding elevation values ​​are matched by vertex numbers, and the matched elevation values ​​are assigned to the vertices of the 2D triangular mesh to generate a 3D triangular mesh with elevation information. The 3D triangular mesh with elevation information is transformed into a continuous 3D terrain surface model using the Railworks platform. The platform's built-in mesh rendering interface is called, and the vertex coordinates and connectivity of the 3D triangular mesh are input into the geometry engine. A smooth 3D terrain surface model is generated through a surface fitting algorithm, completing the terrain geometry reconstruction.

[0065] The data processed by the 3D terrain surface model includes Z-coordinate data (elevation values) from the initial 3D point set, as well as elevation and slope attribute data integrated according to the rail transit industry delivery standards. The elevation values ​​are derived from control points and elevation information obtained by total stations and satellite positioning equipment, while the slope data comes from ground feature coordinates and slope measurement results. Each data point is stored as a numerical field in the attribute database and is geometrically associated with the model through vertex coordinates.

[0066] Data processing achieves elevation matching through the mapping relationship between vertex indices and Z-coordinates. A traversal query method is used to align each vertex number with its index position in the elevation value array, ensuring that the elevation value is accurately assigned to the mesh vertex. Attribute data processing supports SQL query statements or API calls based on vertex coordinates through configured data access interfaces, enabling real-time retrieval of elevation and slope attribute values ​​and enhancing the model's data interaction capabilities. The Railworks platform processes mesh data through a geometry engine and surface fitting algorithms to achieve continuous reconstruction of the 3D model.

[0067] The 3D terrain surface model outputs a continuous 3D geometric model with elevation information and an attribute database, including vertex coordinates, connectivity relationships, and elevation and slope attribute values. The output data is connected to the downstream bridge design and roadbed design modules through the Railworks platform's data synchronization mechanism. When the model detects changes in elevation attributes or geometric parameters, it automatically updates the abutment elevation parameters and slope parameters in the downstream design through database triggers, supporting cross-disciplinary design collaboration.

Claims

1. A terrain modeling method based on the domestic 3D graphics platform Railworks, characterized in that, include: Step 1: Collect topographic data along the rail transit project route. The topographic data includes control points, elevations, slopes, and ground feature information obtained by surveying equipment, as well as dwg format topographic map files and digital elevation model (DEM) data processed by AutoCAD. Perform layer standardization on the dwg format topographic map files, separating elevation points and contour lines into different layers to generate a structured raw data pool including the topographic data. Step 2: Extract discrete 3D point sets from the structured raw data pool through the data interface of the Railworks platform, filter invalid data points, and generate an initial 3D point set set; Step 3: Preprocess the initial three-dimensional point set, remove points with duplicate spatial coordinates, and project the preprocessed three-dimensional point set onto a two-dimensional plane, retaining the X and Y coordinates to form a two-dimensional point set sequence; Step 4: Mesh the two-dimensional point set sequence, use the Gift Wrapping algorithm to calculate the convex hull boundary of the point set, and then use the Delaunay triangulation algorithm to generate a triangular mesh within the convex hull, outputting a two-dimensional triangular mesh. Step 5: Associate the vertices of the two-dimensional triangular mesh with the Z coordinates in the initial three-dimensional point set to generate a three-dimensional triangular mesh with elevation information, and reconstruct the three-dimensional terrain surface model using the Railworks platform. Step 6: Add an attribute database to the three-dimensional terrain surface model. The attribute database integrates elevation and slope attributes according to the rail transit industry delivery standards. Step 7: Connect the 3D terrain surface model with the attribute database to the downstream bridge and roadbed design modules through the data synchronization mechanism of the Railworks platform; when the 3D terrain surface model changes, the design parameters in the downstream design modules are automatically updated through database triggers.

2. The terrain modeling method based on the domestic 3D graphics platform Railworks according to claim 1, characterized in that, Step 1 includes: Control points and elevation information are obtained using a total station, and the coordinates and slope data of ground features are obtained using satellite positioning equipment. Receive DWG format topographic map files, identify the layer structure in the file, assign elevation points to elevation point layers, and assign contour lines to contour line layers; Analyze digital elevation model (DEM) data, extract elevation values ​​of grid points, and generate point set coordinate information; The control points, elevation information, feature coordinates, slope data, elevation point layers, contour line layers, and point set coordinate information are integrated to form the structured raw data pool.

3. The terrain modeling method based on the domestic 3D graphics platform Railworks according to claim 2, characterized in that, Step 2 includes: Read the elevation point layer and contour line layer of the dwg file from the structured raw data pool, and extract the coordinates of discrete points in the layers; Read the digital elevation model (DEM) data from the structured raw data pool and convert the grid nodes into three-dimensional coordinate points; The extracted discrete point coordinates and 3D coordinates are verified for their range. Abnormal points that exceed the preset coordinate range are deleted, and the verified point coordinates are integrated into the initial 3D point set.

4. The terrain modeling method based on the domestic 3D graphics platform Railworks according to claim 3, characterized in that, Step 3 includes: The initial set of three-dimensional points is traversed to identify points with identical X and Y coordinates. The first point to appear is retained, and subsequent duplicate points are deleted. The deduplicated 3D point set is projected onto a 2D plane, retaining the X and Y coordinates, and the Z coordinate is stored as an elevation attribute. The projected two-dimensional points are arranged in coordinate order to form the two-dimensional point set sequence.

5. The terrain modeling method based on the domestic 3D graphics platform Railworks according to claim 4, characterized in that, Step 4, which involves meshing the two-dimensional point set sequence, includes: The Gift Wrapping algorithm is used to process the two-dimensional point set sequence. The lowest point in the point set is selected as the starting point, and the point set is traversed in ascending order of polar angle to determine the convex hull boundary vertices. A convex hull boundary is established based on the vertices of the convex hull boundary. Within the convex hull boundary, the Delaunay triangulation algorithm is executed to generate a triangular mesh, which satisfies the empty circle rule. For triangular meshes that satisfy the empty circle rule, a divide-and-conquer strategy is adopted for strip terrain data to divide the point set into multiple sub-regions for parallel triangulation processing. The triangulation results of multiple sub-regions are subjected to boundary fusion processing to output the two-dimensional triangular mesh.

6. The terrain modeling method based on the domestic 3D graphics platform Railworks according to claim 5, characterized in that, Step 5, reconstructing the three-dimensional terrain surface model, includes: Establish a mapping relationship between the vertex indices of the two-dimensional triangular mesh and the Z coordinates in the initial three-dimensional point set; Match the corresponding elevation value by vertex number, and assign the matched elevation value to the vertex of the two-dimensional triangular mesh; The Railworks platform was used to convert a 3D triangular mesh with elevation data into a continuous 3D terrain surface model.

7. The terrain modeling method based on the domestic 3D graphics platform Railworks according to claim 6, characterized in that, The additional attribute database in step 6 includes: In accordance with the delivery standards of the rail transit industry, elevation and slope attribute fields are added to the three-dimensional terrain surface model; Establish the association between the attribute database and the 3D terrain surface model, and store elevation and slope values; Configure the data access interface to query the corresponding elevation and slope attribute values ​​by vertex coordinates.

8. The terrain modeling method based on the domestic 3D graphics platform Railworks according to claim 7, characterized in that, The data synchronization mechanism in step 7 includes: Establish a data association table between the three-dimensional terrain surface model and the downstream bridge design and roadbed design; Configure database triggers to monitor changes in elevation attributes and geometric parameters of the 3D terrain surface model; When a data change is detected, the abutment elevation parameters in the downstream bridge design and the slope parameters in the roadbed design are updated through a data synchronization mechanism.

9. The terrain modeling method based on the domestic 3D graphics platform Railworks according to claim 8, characterized in that, Also includes: When performing step 4, the granularity of sub-region division is dynamically adjusted according to the point set density; When performing step 7, a version management mechanism is established to record the historical changes of the 3D terrain surface model.

10. A terrain modeling device based on the domestic 3D graphics platform Railworks, applied to the terrain modeling method based on the domestic 3D graphics platform Railworks as described in any one of claims 1 to 9, characterized in that, include: The data acquisition module is configured to collect topographic data along the rail transit engineering project. The topographic data includes control points, elevations, slopes, and ground feature information obtained by surveying equipment, as well as dwg format topographic map files and digital elevation model (DEM) data processed by AutoCAD. Layer standardization is performed on the dwg format topographic map files to separate elevation points and contour lines to different layers, generating a structured raw data pool that includes the topographic data. The point set extraction module is configured to extract discrete 3D point sets from the structured raw data pool through the data interface of the Railworks platform, filter invalid data points, and generate an initial 3D point set set. The preprocessing component is configured to preprocess the initial set of three-dimensional points, remove points with duplicate spatial coordinates, and project the preprocessed set of three-dimensional points onto a two-dimensional plane, retaining the X and Y coordinates to form a sequence of two-dimensional points. The meshing module is configured to perform meshing on the two-dimensional point set sequence, calculate the convex hull boundary of the point set using the Gift Wrapping algorithm, and then generate a triangular mesh within the convex hull using the Delaunay triangulation algorithm, outputting a two-dimensional triangular mesh. The model reconstruction module is configured to associate the vertices of the two-dimensional triangular mesh with the Z coordinates in the initial three-dimensional point set to generate a three-dimensional triangular mesh with elevation information, and to reconstruct a three-dimensional terrain surface model using the Railworks platform. An attribute attachment module is configured to attach an attribute database to the three-dimensional terrain surface model, the attribute database integrating elevation and slope attributes according to rail transit industry delivery standards. The data synchronization module is configured to connect the 3D terrain surface model with the attribute database to the downstream bridge and roadbed design modules through the data synchronization mechanism of the Railworks platform; when the 3D terrain surface model changes, the design parameters in the downstream design modules are automatically updated through database triggers.

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