Viewpoint-based railway BIM (Building Information Modeling) visualization processing method and system

Abstract

The invention provides a railway BIM (Building Information Modeling) visualization processing method and system based on viewpoints. The method comprises the following steps: S1, building a lightweight railway BIM model; the lightweight railway BIM model is configured as follows: after a target viewpoint of a target user is obtained, corresponding block data is called for compression transmission; s2, building a three-dimensional visual window; the three-dimensional visual window is configured to analyze a target viewpoint of the target user after the target user clicks a viewpoint label, and receive compressed block data for data analysis and batch rendering; s3, building a block chain collaboration system; s4, establishing a viewpoint management network; s5, establishing a roaming animation output network; dynamically allocating animation time to each viewpoint label in the viewpoint label set, and smoothing a roaming animation path; and the light is tracked in real time for roaming animation output. According to the technical scheme in the embodiment of the invention, lightweight data transmission, efficient viewpoint switching and roaming animation output can be realized.

Description

Technical Field

[0001] The present invention belongs to the field of BIM and digital application technology, and particularly relates to a viewpoint-based railway BIM visualization processing method and system. Background Art

[0002] With its technical characteristics of visualization, coordination, simulation, optimization and information output, BIM has been successfully applied to various types of engineering construction at home and abroad. BIM visualization technology is also widely used in the design, construction and operation and maintenance stages of engineering construction.

[0003] However, for the dynamic management and quantity processing of BIM visualization viewpoints in complex large-scale railway hub projects, due to the huge amount of BIM model data, low model lightweightness, weak carrying capacity of the information management platform, and difficulty in innovating viewpoint management technology, problems such as long viewpoint query positioning and viewpoint switching are time-consuming and inefficient in the application of BIM technology viewpoints.

[0004] In addition, there are problems such as weak viewpoint collaborative sharing and authority management, and poor viewpoint roaming animation generation effects, which seriously affect the level of digital collaboration and data management efficiency during railway construction, and hinder the further development and in-depth application of BIM technology visualization in the field of railway engineering construction. Summary of the Invention

[0005] The embodiments of the present invention provide a viewpoint-based railway BIM visualization processing method and system, which can significantly improve the BIM data interaction efficiency and visualization collaboration level.

[0006] In a first aspect, an embodiment of the present invention provides a viewpoint-based railway BIM visualization processing method, comprising:

[0007] S1, building a lightweight railway BIM model; the lightweight railway BIM model is configured to: after obtaining the target viewpoint of the target user, retrieve the corresponding block data for compression and transmission;

[0008] S2, building a three-dimensional visualization window; the three-dimensional visualization window is configured to: after the target user clicks the viewpoint tag, parse the target viewpoint of the target user, and receive compressed block data for data parsing and batch rendering;

[0009] S3: Building a blockchain collaborative system. The blockchain collaborative system is configured to: create an enterprise-level private chain, create roles and assign contract permissions based on the target user's identity information in the private chain; record the target user's operation log and generate a hash value, and splice each operation log of the target user to form an irreversible chain structure;

[0010] S4, building a viewpoint management network; the viewpoint management network is configured to: set a new button in the 3D visualization window to create and save viewpoint tags, set a collaborative sharing button to transfer and coordinate viewpoint tags; and preload frequently accessed viewpoint tags based on a user behavior prediction model;

[0011] S5, building a roaming animation output network; the roaming animation output network is configured to: dynamically allocate animation time to each viewpoint tag in the viewpoint tag set, and smooth the roaming animation path; and trace rays in real time to output the roaming animation.

[0012] Preferably, in step S1:

[0013] The construction process of the lightweight railway BIM model is specifically as follows: BIM model data and GIS terrain data are uniformly converted into a standard three-dimensional space coordinate system and data fusion is performed to obtain an initial railway BIM model; component features in the initial railway BIM model are extracted, and unnecessary model faces in the initial railway BIM model are eliminated to obtain a lightweight railway BIM model;

[0014] The process of retrieving the corresponding block data for compression and transmission is specifically as follows: dividing the lightweight railway BIM model into multiple standard three-dimensional blocks; based on the frustum clipping technology, determining each visible three-dimensional block within the visible range of the target viewpoint from the standard three-dimensional blocks; based on the spatial distance between the target viewpoint and the visible three-dimensional block, extracting block data of different levels of detail for the visible three-dimensional block; and after extracting the block data of each visible three-dimensional block, compressing and transmitting it.

[0015] Preferably, in step S2:

[0016] The viewpoint tag is bound to the GIS terrain data in the lightweight railway BIM model; the viewpoint tag includes: the three-dimensional spatial coordinates of the target viewpoint, the viewing angle parameters of the target viewpoint and the associated component ID;

[0017] The received compressed block data is parsed and rendered in batches, specifically: the compressed block data in the lightweight railway BIM model is received, and the corresponding visual three-dimensional blocks are restored; on the Web side, components in the visual three-dimensional blocks are extracted based on a lightweight renderer and batch rendered; on the mobile side, the surrounding environment of each visual three-dimensional block is rendered in real time based on SLAM technology.

[0018] Preferably, in step S3:

[0019] The process of creating roles and assigning contract permissions specifically includes: creating a design role, a construction role, and an operation and maintenance role; limiting the design role's permissions to create and modify viewpoint tags and share viewpoint folders through smart contracts; limiting the construction role's permissions to view viewpoint tags and generate roaming animations; and limiting the operation and maintenance role's permissions to view operation logs; dynamically setting access permissions for the viewpoint folders, updating them in real time to the blockchain ledger, and providing feedback through color coding;

[0020] The process of forming the irreversible chain structure is specifically as follows: when the target user performs an operation, the smart contract is triggered to generate an operation log; based on a hash algorithm, a hash value of the current operation log is calculated; the hash value of the current operation log is concatenated with the hash value of the previous operation log to generate a new hash value to form an irreversible chain structure, and the current operation log and the new hash value are stored in the blockchain for node synchronization verification.

[0021] Preferably, in step S4:

[0022] The process of establishing and saving the viewpoint label is specifically as follows: based on the BIM model data and GIS terrain data, the corresponding railway engineering line, engineering specialty and work site location are searched in the lightweight railway BIM model, and the viewpoint label is generated in the three-dimensional visualization window through the new button.

[0023] Preferably, in step S4:

[0024] The process of preloading high-frequency viewpoint tags is specifically as follows: based on the historical operation records of the target user, high-frequency viewpoint tags with access popularity higher than a preset threshold are preloaded into the local cache; and low-frequency viewpoint tags with access popularity lower than the preset threshold in the local cache are released using the LRU algorithm.

[0025] Preferably, in step S5:

[0026] The process of outputting the roaming animation is specifically as follows: selecting key viewpoints from the viewpoint tag set as control points, generating a smooth path based on a fifth-order Bezier curve interpolation algorithm, and performing viewpoint switching; dynamically allocating the time ratio of key viewpoint animation frames, performing dynamic rendering based on real-time viewpoint switching, and calculating light reflection, refraction, and shadows in real time to simulate the lighting effects of a railway tunnel.

[0027] In a second aspect, an embodiment of the present invention provides a viewpoint-based railway BIM visualization processing system, comprising:

[0028] A railway BIM model construction unit is used to build a lightweight railway BIM model; the lightweight railway BIM model is configured to: after obtaining the target viewpoint of the target user, retrieve the corresponding block data for compression and transmission;

[0029] A visualization window construction unit is configured to construct a three-dimensional visualization window; the three-dimensional visualization window is configured to: after the target user clicks a viewpoint tag, parse the target viewpoint of the target user, and receive compressed block data for data parsing and batch rendering;

[0030] A collaborative system construction unit is used to build a blockchain collaborative system; the blockchain collaborative system is configured to: create an enterprise-level private chain, create roles and assign contract permissions based on the identity information of the target user in the private chain; record the target user's operation log and generate a hash value, and splice each operation log of the target user to form an irreversible chain structure;

[0031] A management network construction unit is used to build a viewpoint management network; the viewpoint management network is configured to: set a new button in the 3D visualization window to create and save viewpoint tags, set a collaborative sharing button to transfer and coordinate viewpoint tags; and preload frequently accessed viewpoint tags based on a user behavior prediction model;

[0032] The roaming animation construction unit is used to build a roaming animation output network; the roaming animation output network is configured to: dynamically allocate animation time to each viewpoint tag in the viewpoint tag set and smooth the roaming animation path; and trace rays in real time to output the roaming animation.

[0033] In a third aspect, an embodiment of the present invention provides an electronic device, comprising:

[0034] at least one processor; and

[0035] a memory communicatively connected to the at least one processor; wherein,

[0036] The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the viewpoint-based railway BIM visualization processing method described in any embodiment of the present invention.

[0037] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the viewpoint-based railway BIM visualization processing method described in any embodiment of the present invention when executed.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The technical solution in the embodiments of the present invention achieves efficient transmission of model data by building a lightweight railway BIM model, and reduces display end memory usage through block compression. By establishing a private chain + smart contract network, a blockchain collaborative sharing system is formed to achieve collaborative sharing of viewpoint data. An improved Bezier curve interpolation algorithm is used to generate smooth paths for roaming animations, and real-time rendering optimization is used to improve the efficiency and resolution of comic output. This is particularly effective for dynamic management of three-dimensional viewpoints, multi-disciplinary collaborative sharing, and intelligent roaming animation generation for large and complex railway hub projects. By integrating a lightweight engine, dynamic optimization algorithms, and intelligent animation generation technology, the efficiency of BIM data interaction and the level of visual collaboration are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 A schematic diagram of the flow of a viewpoint-based railway BIM visualization processing method provided in the first embodiment of the present invention;

[0042] Figure 2 This is an application interface diagram of a three-dimensional visualization window provided in the first embodiment of the present invention;

[0043] Figure 3 This is a diagram showing the display interface for constructing a viewpoint tag provided in the first embodiment of the present invention;

[0044] Figure 4 A schematic diagram of the structure of a viewpoint-based railway BIM visualization processing system provided in the second embodiment of the present invention;

[0045] Figure 5 This is a structural diagram of an electronic device provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0048] Before introducing the embodiments of the present invention, it should be noted that the problems existing in the prior art BIM visualization technology are specifically reflected in the following aspects:

[0049] 1. Low viewpoint positioning and switching efficiency. Traditional BIM platforms rely on manual viewpoint adjustment. In BIM visualization applications for large, complex railway hubs encompassing multiple disciplines, including tracks, bridges, and signals, finding a specific equipment viewpoint takes an average of approximately 5 minutes, significantly exceeding the industry's expected benchmark of 1 minute or less, significantly reducing work efficiency.

[0050] 2. Weak viewpoint collaborative sharing and permission management. The existing BIM platform's viewpoint sharing mechanism has numerous flaws. For one thing, the lack of a comprehensive permission control system can lead to users accidentally deleting viewpoints created by others, or data conflicts arising when multiple people are working simultaneously. Furthermore, the lack of viewpoint sharing functionality and intuitive status indicators prevents users from quickly locating the corresponding viewpoints for multi-disciplinary, multi-stage collaborative applications, or from quickly identifying the sharing permissions for a particular viewpoint folder, increasing operational risks.

[0051] 3. Viewpoint walkthrough animation generation is inefficient and produces poor results. Existing BIM viewpoint walkthrough animation generation methods typically rely on pre-defined fixed paths and are unable to adapt to the dynamic requirements of complex railway scenarios. It is difficult to quickly generate high-quality viewpoint walkthrough animations based on dynamic animation sequences of user-defined viewpoints to meet the needs of different project users, such as the cable laying sequence for signal engineering and the dynamic display of signal equipment installation.

[0052] Example 1

[0053] Figure 1This is a flow chart of the viewpoint-based railway BIM visualization processing method provided in the first embodiment of the present invention. This embodiment is applicable to the situation where a local visualization and dynamic display of a BIM data model is performed based on a BIM viewpoint. The method can be executed by the viewpoint-based railway BIM visualization processing system in the embodiment of the present invention. The system can be implemented in software and / or hardware and integrated into an electronic device.

[0054] like Figure 1 As shown, the method specifically includes the following steps:

[0055] S1, build a lightweight railway BIM model. The lightweight railway BIM model is configured to: after obtaining the target viewpoint of the target user, retrieve the corresponding block data for compressed transmission.

[0056] The essence of a target viewpoint is an observation point that includes spatial coordinates, viewing angle parameters, and associated components. Target users can create, modify, and delete target viewpoints based on their permissions, and can also share target viewpoints with other users.

[0057] It should be noted that due to the large amount of data in traditional railway BIM models, it takes a lot of time to find specific equipment viewpoints during visualization. In the embodiment of the present invention, to improve the positioning and switching speed of BIM model viewpoints, a lightweight engine was developed based on the BIM+GIS information management platform, integrating technologies. The block compression algorithm (LOD+Octree) is used to dynamically load model data in real time, achieving efficient loading of visualization blocks for the current viewpoint and efficient switching from the current viewpoint to the target viewpoint.

[0058] Furthermore, the construction process of the lightweight railway BIM model is specifically as follows: BIM model data and GIS terrain data are uniformly converted into a standard three-dimensional space coordinate system and data fusion is performed to obtain an initial railway BIM model; component features in the initial railway BIM model are extracted, and unnecessary model surfaces in the initial railway BIM model are eliminated to obtain a lightweight railway BIM model.

[0059] Preferably, by developing an adapter interface, the BIM model data and GIS terrain data are uniformly converted into a standard three-dimensional spatial coordinate system, and a method combining Web Mercator and WGS84 ellipsoid projection is used to perform data fusion, eliminate data deviation, and realize multi-source data integration.

[0060] Among them, Web Mercator is a map projection method used in Internet map services, geographic information systems and visualization applications; the Web Mercator projection receives input as WGS84 longitude and latitude, but when projecting, the earth is no longer treated as an ellipsoid, but as a standard sphere to simplify calculations; WGS84 is a globally used earth coordinate system used for GPS positioning and other global navigation systems.

[0061] Among them, there are two projection standards for Web Mercator, namely EPSG4326 and EPSG3857; EPSG4326: a flat map after Web Mercator projection, but still uses WGS84 longitude and latitude to express coordinates; EPSG3857: a flat map after Web Mercator projection, with coordinate units in meters.

[0062] Preferably, the EPSG3857 projection standard is selected for Web Mercator map projection.

[0063] Preferably, semantic-based model simplification technology is used to extract key geometric features of BIM components, such as track curvature and bridge support topological relationships, and eliminate unnecessary detail model surfaces, thereby reducing the amount of data in the BIM model by 70%.

[0064] In the embodiment of the present invention, by completing the design of the BIM+GIS fusion lightweight engine architecture, multi-source data integration and highly lightweight conversion of model data are ensured, and data fusion and coordinate system unification are achieved.

[0065] Furthermore, the process of retrieving the corresponding block data for compression and transmission is specifically as follows: dividing the lightweight railway BIM model into multiple standard three-dimensional blocks; based on the frustum clipping technology, determining each visible three-dimensional block within the visible range of the target viewpoint from the standard three-dimensional blocks; based on the spatial distance between the target viewpoint and the visible three-dimensional block, extracting block data of different levels of detail for the visible three-dimensional block; after extracting the block data of each visible three-dimensional block, compressing and transmitting it.

[0066] Preferably, the lightweight railway BIM model is divided into three-dimensional cube blocks with a side length of 50 meters according to the Octree structure, and each block contains a subset of professional models such as tracks and signal equipment.

[0067] Preferably, based on the view frustum clipping technology, only the block data within the visible range of the target viewpoint is loaded, and the block data that needs to be recorded is dynamically compressed and transmitted.

[0068] Preferably, the LOD detail level of each visible 3D block is dynamically adjusted based on the spatial distance between the target viewpoint and the visible 3D block. When the spatial distance is greater than 500 meters, it is the distant view, and LOD1 simplified geometry is loaded, retaining only the outline; when the spatial distance is between 100-500 meters, it is the mid-view, and LOD2 medium-detail models are loaded, including equipment outlines and key attributes; when the spatial distance is less than 100 meters, it is the near view, and LOD3 full-detail models are loaded, including refined data such as bolts and cable directions.

[0069] The Draco compression algorithm is preferably used to compress block data. Through dynamic compression processing, it achieves a lossless compression rate of 85%, reduces transmission bandwidth requirements to 30% of traditional methods, and reduces memory usage by 60% (measured data: when loading the Shanghai-Suzhou-Lake High-Speed ​​Railway Hub model, the peak memory usage dropped from 12GB to 4.8GB).

[0070] While extracting the block data of each visible three-dimensional block, based on the historical operation records of the target user, preload non-visible blocks with access popularity higher than the preset threshold into the local cache; at the same time, the LRU algorithm is used to release non-visible blocks in the local cache with access popularity lower than the preset threshold. Specifically: Based on AI artificial intelligence and / or LSTM neural network algorithms, train user behavior prediction models, analyze historical operation records, and preload adjacent blocks and high-frequency access professional models into the local cache. The LRU (least recently used) algorithm is used to manage cached data to ensure that hot data resides in memory and cold data is automatically released, thereby achieving preloading and cache optimization management. WebWorkers multi-threading technology is used on the Web side, and GPU asynchronous computing is used on the mobile side to achieve parallel loading of multiple blocks. The measured response time is ≤0.3 seconds (traditional method ≥2 seconds).

[0071] In the embodiment of the present invention, preloading and cache management and parallel loading optimization are adopted to form a real-time dynamic loading mechanism for viewpoint data.

[0072] Table 1 compares the test indicators of the traditional method and the method of the present application. As shown in Table 1, the technical solution of the present invention introduces an innovative lightweight model engine, block compression algorithm and dynamic loading technology, which effectively improves the viewpoint switching speed by 86.7% and reduces the peak memory usage by 60%.

[0073] Table 1 Comparison of test indicators between traditional method and this application method

[0074] index Traditional methods This application method Improvement ratio Peak memory usage 12.0GB 4.8GB 60％ Average viewpoint switching response time 2.1 seconds 0.28 seconds 86.7％

[0075] The technical solution in the embodiments of the present invention addresses the problem of low viewpoint positioning and switching efficiency in the visualization application process of traditional BIM platforms, proposes a lightweight architecture, and configures a block-compressed data transmission method, which can efficiently complete viewpoint positioning and switching.

[0076] S2, building a 3D visualization window; the 3D visualization window is configured to: after the target user clicks the viewpoint label, parse out the target user's target viewpoint, and receive compressed block data for data parsing and batch rendering.

[0077] In order to facilitate user viewpoint application access, a three-dimensional visualization window is embedded in the web and mobile terminals of the BIM information platform, supporting users to quickly locate the target viewpoint by clicking labels (such as "Signal Building" and "Signal Room"), with a response time of ≤0.3 seconds.

[0078] Furthermore, the viewpoint tag is bound to the GIS terrain data in the lightweight railway BIM model. The viewpoint tag contains: the three-dimensional spatial coordinates of the target viewpoint, the viewing angle parameters of the target viewpoint and the associated component ID.

[0079] Optionally, pre-define viewpoint tags for key locations in the BIM model (e.g., "cable entry room" or "signal room") and bind them to GIS coordinates. Viewpoint tags are stored in JSON format and contain spatial coordinates (X, Y, Z), viewing angle parameters (pitch and yaw), and associated component IDs.

[0080] Optionally, users can click a viewpoint tag in the 3D visualization window to trigger a viewpoint location request. The lightweight engine then parses and searches for the block ID corresponding to the viewpoint tag, prioritizing loading LOD3 data from the cache. The rendering engine then smoothly transitions the viewpoint to the target coordinates and highlights the BIM viewpoint model within a 50-meter radius of the seam, enabling rapid location of the labeled viewpoint.

[0081] Furthermore, the compressed block data is received for data analysis and batch rendering, specifically: the compressed block data in the lightweight railway BIM model is received, and the corresponding visual three-dimensional blocks are restored; on the Web side, the components in each visual three-dimensional block are extracted based on the lightweight renderer and batch drawn; on the mobile side, the surrounding environment of each visual three-dimensional block is rendered in real time based on SLAM technology.

[0082] In the embodiment of the present invention, lightweight rendering is used to ensure smooth three-dimensional viewpoint application of large-volume models.

[0083] Figure 2 This is an application interface diagram of the three-dimensional visualization window provided in the first embodiment of the present invention, such as Figure 2As shown, after the target user clicks the viewpoint tag, the target viewpoint in the viewpoint tag is quickly parsed and, based on the target viewpoint, the corresponding block data is retrieved from the lightweight railway BIM model. After receiving the corresponding block data, each 3D block is restored. Due to the different levels of detail of different blocks, the restored block details also vary. For LOD1 blocks, only the geometry needs to be simplified and the block outline rendered; for LOD2 blocks, the equipment outline needs to be retained for rendering; for LOD3 blocks, details such as bolt and cable routing need to be rendered.

[0084] In this embodiment of the present invention, the API provided by the BIM information platform enables real-time capture of the user's current viewing angle parameters, model visibility status, and spatial coordinates. The BIM information platform accurately captures various information during the user's operation, providing a data foundation for subsequent viewpoint storage and processing, thus enabling viewpoint acquisition.

[0085] Alternatively, on the web side of the BIM information platform, a lightweight renderer based on the Three.js engine was developed, using InstancedMesh technology to batch-draw identical components, such as signal clips, reducing draw calls by 90%. Furthermore, the web side supports GPU-accelerated computing with WebGL 2.0, enabling smooth interaction with large-scale models.

[0086] The mobile version of the BIM information platform integrates the native AR SDK of ARKit / ARCore, using SLAM (Simultaneous Localization and Mapping) technology to achieve high-precision model overlays with a positioning error of ≤5cm. An adaptive resolution strategy is employed: the rendering resolution (720p-2K) is dynamically adjusted based on the device's GPU performance, ensuring a stable frame rate above 60fps.

[0087] S3, builds a blockchain collaborative system; the blockchain collaborative system is configured to: create an enterprise-level private chain, create roles and assign contract permissions based on the identity information of the target user in the private chain; record the target user's operation log and generate a hash value, and splice each operation log of the target user to form an irreversible chain structure.

[0088] In an embodiment of the present invention, in order to strengthen the viewpoint application authority and status management, a collaborative sharing system based on blockchain is constructed, and the authority of viewpoint operations is set according to the role (design / construction / operation and maintenance). The authority status is fed back in real time through folders marked with different colors, including unshared (white), shared (yellow), and shared by others (red).

[0089] It should be noted that each folder stores a different set of viewpoint tags. By clicking on a different viewpoint tag, the corresponding block image can be displayed in the 3D visualization window.

[0090] In this embodiment of the present invention, a tree-like structure is used to organize and manage viewpoint data, supporting retrieval based on multiple dimensions, such as discipline, stage, and creator. For example, in a railway project, viewpoint data can be categorized and stored according to different stages, such as design and construction, as well as different disciplines, such as signaling, communications, substation, power, and building construction, making it easy for users to quickly find and access required viewpoints.

[0091] Figure 3 This is a diagram showing the display interface for constructing a viewpoint tag provided in the first embodiment of the present invention, as shown in FIG. Figure 3 As shown, users can manage viewpoint sets and viewpoints in the BIM information platform by selecting a viewpoint tag and performing operations such as "Modify Name" and "Delete." For example, in the signaling field, corresponding viewpoints are created for the equipment layout in locations such as the signal machinery room, cable entry room, lightning protection distribution room, and power panel at different work sites. Users can quickly understand the general model content corresponding to a viewpoint when viewing the viewpoint list, using functions and information such as thumbnails, fields, viewpoint names, and searches, allowing them to quickly locate the desired view.

[0092] Furthermore, the process of creating roles and assigning contract permissions is as follows: creating design roles, construction roles, and operation and maintenance roles; limiting the design role to the permissions to create and modify viewpoint tags and share viewpoint folders through smart contracts, limiting the construction role to the permissions to view viewpoint tags and generate roaming animations, and limiting the operation and maintenance role to the permissions to view operation logs; dynamically setting the access permissions of viewpoint folders, updating them in real time to the blockchain ledger, and providing feedback through color coding.

[0093] Optionally, Hyperledger Fabric can be used to build an enterprise-level private chain, with nodes distributed according to the roles of designer, constructor, and operator to ensure that data is only shared within the authorized scope. Smart contracts (Chaincode) define permission rules:

[0094] Design role: Can create and modify viewpoints, and share folders with construction and operation and maintenance roles.

[0095] Construction role: Can view viewpoints and generate fly-through animations, but cannot modify original data.

[0096] Operation and Maintenance role: Can only view historical viewpoint logs and does not have the right to share or delete them.

[0097] When a user logs in, their identity is verified through a digital certificate (X.509), and the system automatically associates their role permissions and dynamically binds permissions. The folder permission status is updated in real time to the blockchain ledger and reflected through color markings on the front-end interface:

[0098] White folder: Not shared, editable only by the creator.

[0099] Yellow folder: Shared, collaborators can view but not modify it.

[0100] Red folder: shared with others, local users are prohibited from deleting or editing.

[0101] In the three-dimensional visualization interface, the folder icon dynamically renders color according to the permission status to achieve visual interactive design. When the user hovers the viewpoint folder, permission details such as sharer, sharing time, operation record, etc. pop up.

[0102] Table 2 is a comparison of viewpoint data security tests of the present application method. As shown in Table 2, the technical solution of the present invention introduces blockchain technology, establishes a collaborative sharing system and a data tamper-proof mechanism, and significantly improves the efficiency and benefits of viewpoint applications through multi-professional collaboration. At the same time, the problem of weak authority management is effectively solved, and data security management has made a qualitative leap.

[0103] Table 2 Comparison of viewpoint data security tests of this application method

[0104] Test items Test Method result Tamper detection rate Try to modify the historical log hash value 100% trigger alarm Intercepting unauthorized operations Construction character trying to modify yellow folder Smart contract interception, 100% success rate Audit traceability integrity Tracing logs after simulating a delete operation Completely record the operator's IP and timestamp

[0105] In an embodiment of the present invention, digital signature technology, blockchain encryption technology and homomorphic encryption algorithm are used to verify user permissions, and the sharing status of folders is rendered in real time through color coding. Blockchain encryption technology ensures that user permission information and sharing records cannot be tampered with and are traceable; the homomorphic encryption algorithm allows specific operations, such as permission verification, to be performed on encrypted data without decrypting the data, further ensuring data privacy and security. At the same time, a zero-trust network architecture is adopted to perform strict identity authentication and permission checks on each access request, even in an internal network environment, effectively preventing data leakage and illegal access. Digital signature technology is used to verify user permissions to ensure that only legitimate users can perform corresponding operations. The sharing status of folders is rendered in real time through color coding, allowing users to intuitively understand the permission types of viewpoints and viewpoint sets.

[0106] Furthermore, the process of forming an irreversible chain structure is as follows: when the target user performs an operation, the smart contract is triggered and an operation log is generated; based on the hash algorithm, the hash value of the current operation log is calculated; the hash value of the current operation log is concatenated with the hash value of the previous operation log to generate a new hash value to form an irreversible chain structure, and the current operation log and the new hash value are stored in the blockchain for node synchronization verification.

[0107] Optionally, data security management can be achieved through hash chain storage, tamper detection, and traceability of operation logs. In the log structure design, each operation record includes the operation type (create / modify / share), user ID, timestamp, and data hash value. The hash generation algorithm SHA-256 ensures uniqueness and collision resistance.

[0108] The specific chain storage process is as follows:

[0109] S101: The user performs an operation, such as sharing a folder, to trigger a smart contract;

[0110] S102: The contract generates an operation log and calculates the hash value H n =SHA256(log n );

[0111] S103: H n Hash H with the previous log n-1 Splice to generate a new hash H new =SHA256(H n ||H n-1 ), forming an irreversible chain structure;

[0112] S104: Write the operation log and hash value into the blockchain, and the distributed nodes will verify it synchronously.

[0113] Furthermore, when multiple users modify the same folder at the same time, the smart contract sorts by timestamp and only accepts the first valid operation. Subsequent operations require re-obtaining the latest data version; the creator can revoke sharing permissions at any time, and the contract automatically updates the status and notifies relevant users.

[0114] S4, build a viewpoint management network; the viewpoint management network is configured as follows: set a new button in the 3D visualization window to create and save viewpoint tags, set a collaborative sharing button to transfer and coordinate viewpoint tags; preload high-frequency access viewpoint tags and low-frequency access viewpoint tags based on the user behavior prediction model.

[0115] Specifically, a new button and a collaborative sharing button are set in the 3D visualization window to realize the construction, storage, transmission and coordination of viewpoint labels; based on AI artificial intelligence and LSTM neural network algorithms, the viewpoint loading strategy is dynamically optimized, and high-frequency viewpoint labels are preloaded based on the user behavior prediction model, and low-frequency viewpoint labels are released.

[0116] In an embodiment of the present invention, in order to facilitate the quick and convenient management of BIM model viewpoint applications, the BIM+GIS three-dimensional visualization window is used to perform viewpoint creation, storage, collaboration and optimization management applications based on project, professional and work site classification.

[0117] Furthermore, the process of establishing and saving viewpoint labels is as follows: based on the BIM model data and GIS terrain data, the corresponding railway engineering lines, engineering disciplines and work site locations are found in the lightweight railway BIM model, and the viewpoint labels are generated in the 3D visualization window through the New button.

[0118] Optionally, using BIM+GIS data, you can quickly locate the corresponding railway project route, discipline, and work site within the BIM model. You can then create and save viewpoints using the New button in the 3D window. For example, in the Shanghai-Suzhou-Lake High-Speed ​​Railway Project, the Signaling Department's Shengze Station Signal Tower. Double-clicking the target viewpoint will quickly analyze the spatial coordinates, viewing angle parameters, and model visibility configuration for the desired viewpoint, enabling viewpoint model switching and information query and display.

[0119] Optionally, the collaborative sharing button can be used to achieve the transfer and coordination of viewpoints. When applied, the angle and size of the current viewport can be adjusted at will without affecting the current viewpoint information. Click on the model component to highlight it, and query the model properties, completion files and other content associated with the model, which greatly improves the application efficiency in the design and construction plan optimization discussion.

[0120] Optionally, based on AI artificial intelligence and LSTM neural network algorithms, it dynamically optimizes viewpoint loading strategies and preloads frequently accessed viewpoint data based on user behavior prediction models, improving switching efficiency by 70%.

[0121] Furthermore, the process of preloading high-frequency viewpoint tags is as follows: based on the historical operation records of the target user, high-frequency viewpoint tags with access popularity higher than a preset threshold are preloaded into the local cache; and the low-frequency viewpoint tags with access popularity lower than a preset threshold in the local cache are released using the LRU algorithm.

[0122] In the embodiment of the present invention, preloading and cache management are used for parallel loading optimization to form a real-time dynamic loading mechanism for viewpoint data, thereby achieving high-speed switching of viewpoints.

[0123] S5, building a roaming animation output network; the roaming animation output network is configured to: dynamically allocate animation time to each viewpoint tag in the viewpoint tag set, and smooth the roaming animation path; and trace rays in real time to output the roaming animation.

[0124] Furthermore, the process of roaming animation output is specifically as follows: key viewpoints selected from the viewpoint tag set are used as control points, a smooth path is generated based on the fifth-order Bezier curve interpolation algorithm, and viewpoint switching is performed; the key viewpoint animation frame time ratio is dynamically allocated, dynamic rendering is performed based on real-time viewpoint switching, and light reflection, refraction and shadow are calculated in real time to simulate the lighting effect of the railway tunnel.

[0125] Optionally, AI can be integrated to optimize system integration. The front-end uses the Unity engine to integrate core AI algorithms, integrate VR terminal device interfaces, and integrate voice input and real-time interaction. The back-end uses a Kubernetes cluster to manage distributed rendering tasks, with GPU nodes dedicated to ray tracing and super-resolution computing.

[0126] Optionally, a fifth-order improved Bezier curve may be used to generate a smooth path for the roaming animation.

[0127] The third-order formula of the traditional Bezier curve is as follows:

[0128] P(t)=(1-t) 3 P0+3(1-t) 2 tP1+3(1-t)t 2 P2+t 3 P3

[0129] To adapt to complex paths, the improved fifth-order formula is as follows:

[0130] P(t)=(1-t) 5 P0+5(1-t) 4 tP1+5(1-t) 3 t 2 P2+5(1-t) 2 t 3 P3+5(1-t)t 4 P4+t 5 P5

[0131] Among them, P1 and P4 are determined by the coordinates of the feature points; P2 and P3 are optimized by the gradient descent method to minimize the deviation between the path and the railway logic.

[0132] Optional: VR technology integrates AI-trained speech models, enabling innovative dynamic insertion of voice commands into viewpoints based on manually created viewpoints. The speech recognition model is trained using the Transformer architecture and supports mixed Chinese and English commands. The data integrates 100,000 voice commands from railway engineering scenarios, achieving a recognition accuracy of ≥92%.

[0133] Among them, the instruction mapping and execution path settings are as follows:

[0134] ① Voice input-text conversion ASR-keyword extraction.

[0135] ②The system locates the target area and calculates the best insertion position, such as 50% of the animation timeline.

[0136] ③ Automatically adjust the transition time of the previous and next key frames to ensure the smoothness of the animation.

[0137] Among them, the time ratio of key viewpoint animation frames is dynamically allocated. If the user inserts a key viewpoint frame at time t, the original animation duration T is divided into T1=t, T2=Tt, and the system redistributes the transition time in proportion:

[0138] ΔT new =ΔT old ×T1 / T or T2 / T

[0139] After dynamic optimization, animation output efficiency is increased by more than 50%.

[0140] Optionally, the NVIDIA RTX GPU's hardware ray tracing core (RT Core) can be used to calculate light reflection, refraction, and shadows in real time. Combined with VXGI (Voxel Global Illumination), it can simulate indirect lighting effects in railway tunnels.

[0141] Optionally, Tensor Core can be integrated to run AI models, train over 10,000 railway scenes, and quickly render roaming animations in 1080p and output them in 2K, greatly improving the convenience and application efficiency of roaming animation generation.

[0142] In an embodiment of the present invention, for the same viewpoint set, after the BIM information platform receives the user's instruction to set the playback time of the selected viewpoint set, it will automatically generate a smooth transition animation between viewpoints in the order of viewpoints or time sequence. At the same time, ray tracing technology, real-time rendering engine calculation, AI artificial intelligence prediction algorithm model, and improved Bezier curve algorithm are introduced to automatically adjust the parameters of the interpolation algorithm and optimize the calculation of the camera path, thereby generating a high-quality smooth viewpoint roaming animation that better meets user needs. The BIM information platform supports users to manually insert keyframe viewpoints or VR voice commands to insert keyframe viewpoints, and the length of the video in order to adjust the speed and perspective of the animation. For example, according to the characteristics of different railway engineering specialties (signals, tracks, etc.), the application of technologies such as AI algorithms will automatically optimize the camera path, highlight the key construction steps and equipment details, and support users to insert keyframes through voice commands, adjust the animation speed and perspective, and achieve a more natural and convenient interactive experience.

[0143] Table 3 shows a comparison of efficiency improvement indicators for viewpoint roaming animation production. As shown in Table 3, the technical solution of the present invention introduces AI artificial intelligence training models, improved Bezier curve interpolation algorithms, VR technology, and other technologies to optimize real-time rendering and global illumination technologies, which increases the efficiency of roaming video production by 50% and significantly improves the quality of roaming animation.

[0144] Table 3 Comparison of efficiency improvement indicators for viewpoint roaming animation production

[0145] index Traditional methods This application method Improvement ratio animation production efficiency 4 hours / 10 minutes of animation 2 hours / 10 minutes of animation 50％ 2K rendering frequency 30fps 60fps 100％ Super-resolution reconstruction delay 50ms / frame 15ms / frame 70％

[0146] The following is a complete example to further introduce the specific application process of the present invention:

[0147] For example, during the design phase of the Shanghai-Suzhou-Shanghai Railway, users needed to review the layout of the signal machinery cabinets in the Shengze Station signal tower. This was accomplished by creating, saving, and viewing viewpoints in the 3D window viewpoint area of ​​the BIM information platform. Users could also create and switch viewpoints using AR glasses.

[0148] When operating through the web terminal, click the "Add Viewpoint" button to create a viewpoint set named "Shengze Station Signal Building"; select the viewpoint set, click "Add Viewpoint" on the toolbar, modify the viewpoint name, and click the "Save Viewpoint" button. The system will generate and save the viewpoint name "Shengze Station Signal Building_Signal Machinery Room 1". The system will save the viewing parameters (3D spatial coordinate position, adjustment of viewing angle, yaw angle, etc.), model visibility configuration and thumbnail binding, and store them in the "Shanghai-Suzhou-Lake High-speed Railway_Shengze Station Signal Building_Signal Machinery Room 1" category directory. Double-click "Shengze Station Signal Building_Signal Machinery Room 1" in the viewpoint list, and the system will parse the spatial coordinates, viewing parameters and model visibility configuration of the viewpoint. Click on the model to highlight the relevant models in the signal machinery room, and query the model properties in the attribute information column on the right to view the design details of the empty layout. When operating through AR glasses, the system uses high-precision sensor fusion technology to obtain accurate viewing parameters and record viewpoint information. It also supports voice commands to create and save viewpoints.

[0149] During the construction phase of the railway signal project, the user created a series of viewpoints on the construction progress of the signal equipment installation, forming a folder called "Signal Room Equipment According to Construction Progress Viewpoints".

[0150] After the user clicks the "Share" button, the icon for the "Signal Indoor Equipment Viewpoint According to Construction Progress" folder turns yellow, indicating that the folder has been shared with the collaboration platform. Other users on the collaboration platform can view the roaming animation in this folder but cannot modify the original viewpoint parameters. When a user attempts to delete a red folder shared by others, the operation interception module detects the request and immediately prompts "No operation permission" to log the illegal operation in the audit log. The record includes information such as the operation time, the operating user, and the operation object, which can be used for subsequent audit and traceability.

[0151] After using AI algorithms to generate a walkthrough animation, users share it on the collaborative platform. Construction workers, designers, and supervisors on the collaborative platform can simultaneously view the animation through their respective devices (including mobile devices, computers, VR devices, etc.). Construction workers can view the animation on-site using their mobile devices and make adjustments based on the actual construction progress; designers can immersively view the animation using VR devices, identify design flaws, and provide timely feedback; and supervisors can monitor construction progress through their computers. During the sharing process, blockchain encryption technology ensures that all operation records are traceable, effectively improving the efficiency and quality of collaborative work.

[0152] The user selects the folder and sets the total playback time to 120 seconds. The system sorts the viewpoints by their creation time and uses techniques such as the Bezier curve algorithm to evenly distribute the transition time between viewpoints, generating high-quality fly-through animations and enabling efficient BIM visualization applications.

[0153] The technical solution in the embodiments of the present invention can not only realize the efficient transmission of model data by building a lightweight railway BIM model, and reduce the memory usage of the display end based on block compression; it can also form a blockchain collaborative sharing system by building a private chain + smart contract network to realize the collaborative sharing of viewpoint data; it can also use an improved Bezier curve interpolation algorithm to generate a smooth path for roaming animation, and use real-time rendering optimization to improve the efficiency and resolution of comic output.

[0154] Example 2

[0155] Figure 4 Schematic diagram of the structure of the railway BIM visualization processing system based on viewpoints provided by an embodiment of the present invention. Figure 4 As shown, the system includes:

[0156] The railway BIM model construction unit 100 is used to build a lightweight railway BIM model; the lightweight railway BIM model is configured to: after obtaining the target viewpoint of the target user, retrieve the corresponding block data for compression and transmission.

[0157] The visualization window construction unit 200 is used to build a three-dimensional visualization window. The three-dimensional visualization window is configured to: after the target user clicks the viewpoint tag, parse the target user's target viewpoint, and receive compressed block data for data parsing and batch rendering.

[0158] The collaborative system construction unit 300 is used to build a blockchain collaborative system; the blockchain collaborative system is configured to: create an enterprise-level private chain, create roles and assign contract permissions based on the identity information of the target user in the private chain; record the target user's operation log and generate a hash value, and splice each operation log of the target user to form an irreversible chain structure.

[0159] The management network construction unit 400 is used to build a viewpoint management network; the viewpoint management network is configured as follows: setting a new button in the three-dimensional visualization window to create and save viewpoint tags, setting a collaborative sharing button to transfer and coordinate viewpoint tags; and preloading high-frequency access viewpoint tags based on the user behavior prediction model.

[0160] The roaming animation construction unit 500 is used to build a roaming animation output network; the roaming animation output network is configured to: dynamically allocate animation time to each viewpoint tag in the viewpoint tag set, and smooth the roaming animation path; and trace rays in real time to output the roaming animation.

[0161] The technical solution in the embodiment of the present invention achieves viewpoint positioning in seconds through a lightweight engine, ensures data security through a collaborative sharing system based on blockchain, and improves output quality through AI intelligent animation generation technology. It effectively solves the problems of low viewpoint positioning and switching efficiency, weak viewpoint collaborative sharing and authority management, and low efficiency and poor effect of viewpoint roaming animation generation in multi-professional collaborative viewpoint applications in large-scale railway projects, and realizes efficient, secure and intelligent BIM data full life cycle management.

[0162] Example 3

[0163] Figure 5 1 is a schematic diagram of the structure of an electronic device for implementing a viewpoint-based railway BIM visualization processing method according to an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0164] like Figure 5As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by the at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. Various programs and data required for the operation of the electronic device 10 can also be stored in the RAM 13. The processor 11, ROM 12 and RAM 13 are connected to each other via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0165] Multiple components in the electronic device 10 are connected to the I / O interface 15, including an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0166] The processor 11 can be any general-purpose and / or specialized processing component with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the viewpoint-based railway BIM visualization processing method.

[0167] In some embodiments, the viewpoint-based railway BIM visualization processing method can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the viewpoint-based railway BIM visualization processing method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to execute the viewpoint-based railway BIM visualization processing method in any other appropriate manner (e.g., via firmware).

[0168] Various embodiments of the systems and techniques described herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system-on-chip systems (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system that includes at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0169] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer program may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0170] In the context of the present invention, computer-readable storage media can be tangible media that can contain or store a computer program for use with an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Computer-readable storage media can include but are not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, computer-readable storage media can be machine-readable signal media. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0171] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0172] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0173] A computing system may include clients and servers. The clients and servers are typically remote from each other and typically interact via a communication network. This client-server relationship arises through computer programs running on the respective computers, creating a client-server relationship. The server may be a cloud server, also known as a cloud computing server or cloud host. This server is a hosting product within the cloud computing service ecosystem that addresses the management difficulties and limited scalability of traditional physical hosting and VPS services.

[0174] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0175] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A railway BIM visualization processing method based on viewpoint, characterized in that: include: S1, building a lightweight railway BIM model; the lightweight railway BIM model is configured to: after obtaining the target viewpoint of the target user, retrieve the corresponding block data for compression and transmission; S2, building a three-dimensional visualization window; the three-dimensional visualization window is configured to: after the target user clicks the viewpoint tag, parse the target viewpoint of the target user, and receive compressed block data for data parsing and batch rendering; S3: Building a blockchain collaborative system. The blockchain collaborative system is configured to: create an enterprise-level private chain, create roles and assign contract permissions based on the target user's identity information in the private chain; record the target user's operation log and generate a hash value, and splice each operation log of the target user to form an irreversible chain structure; S4, building a viewpoint management network; the viewpoint management network is configured to: set a new button in the 3D visualization window to create and save viewpoint tags, set a collaborative sharing button to transfer and coordinate viewpoint tags; and preload frequently accessed viewpoint tags based on a user behavior prediction model; S5, building a roaming animation output network; the roaming animation output network is configured to: dynamically allocate animation time to each viewpoint tag in the viewpoint tag set, and smooth the roaming animation path; and trace rays in real time to output the roaming animation.

2. The method according to claim 1, characterized in that In step S1: The construction process of the lightweight railway BIM model is specifically as follows: BIM model data and GIS terrain data are uniformly converted into a standard three-dimensional space coordinate system and data fusion is performed to obtain an initial railway BIM model; component features in the initial railway BIM model are extracted, and unnecessary model faces in the initial railway BIM model are eliminated to obtain a lightweight railway BIM model; The process of retrieving the corresponding block data for compression and transmission is specifically as follows: dividing the lightweight railway BIM model into a plurality of standard three-dimensional blocks; determining each visible three-dimensional block within the visible range of the target viewpoint from the standard three-dimensional blocks based on the frustum clipping technology; Based on the spatial distance between the target viewpoint and the visible 3D block, block data of different detail levels are extracted from the visible 3D block; after the block data of each visible 3D block is extracted, it is compressed and transmitted.

3. The method according to claim 1, characterized in that In step S2: The viewpoint tag is bound to the GIS terrain data in the lightweight railway BIM model; the viewpoint tag includes: the three-dimensional spatial coordinates of the target viewpoint, the viewing angle parameters of the target viewpoint and the associated component ID; The received compressed block data is parsed and rendered in batches, specifically: the compressed block data in the lightweight railway BIM model is received, and the corresponding visual three-dimensional blocks are restored; on the Web side, components in the visual three-dimensional blocks are extracted based on a lightweight renderer and batch rendered; on the mobile side, the surrounding environment of each visual three-dimensional block is rendered in real time based on SLAM technology.

4. The method according to claim 1, wherein In step S3: The process of creating roles and assigning contract permissions specifically includes: creating a design role, a construction role, and an operation and maintenance role; limiting the design role's permissions to create and modify viewpoint tags and share viewpoint folders through smart contracts; limiting the construction role's permissions to view viewpoint tags and generate roaming animations; and limiting the operation and maintenance role's permissions to view operation logs; dynamically setting access permissions for the viewpoint folders, updating them in real time to the blockchain ledger, and providing feedback through color coding; The process of forming the irreversible chain structure is specifically as follows: when the target user performs an operation, the smart contract is triggered to generate an operation log; based on a hash algorithm, a hash value of the current operation log is calculated; the hash value of the current operation log is concatenated with the hash value of the previous operation log to generate a new hash value to form an irreversible chain structure, and the current operation log and the new hash value are stored in the blockchain for node synchronization verification.

5. The method according to claim 1, wherein In step S4: The process of establishing and saving the viewpoint label is specifically as follows: based on the BIM model data and GIS terrain data, the corresponding railway engineering line, engineering specialty and work site location are searched in the lightweight railway BIM model, and the viewpoint label is generated in the three-dimensional visualization window through the new button.

6. The method according to claim 1, characterized in that In step S4: The process of preloading high-frequency viewpoint tags is specifically as follows: based on the historical operation records of the target user, high-frequency viewpoint tags with access popularity higher than a preset threshold are preloaded into the local cache; and low-frequency viewpoint tags with access popularity lower than the preset threshold in the local cache are released using the LRU algorithm.

7. The method according to claim 1, characterized in that In step S5: The process of outputting the roaming animation is specifically as follows: selecting key viewpoints from the viewpoint tag set as control points, generating a smooth path based on a fifth-order Bezier curve interpolation algorithm, and performing viewpoint switching; dynamically allocating the time ratio of key viewpoint animation frames, performing dynamic rendering based on real-time viewpoint switching, and calculating light reflection, refraction, and shadows in real time to simulate the lighting effects of a railway tunnel.

8. A viewpoint-based railway BIM visualization processing system, used to implement the steps of the viewpoint-based railway BIM visualization processing method according to any one of claims 1 to 7, characterized in that: include: Railway BIM model construction unit, used to build lightweight railway BIM models; The lightweight railway BIM model is configured to: after obtaining the target viewpoint of the target user, retrieve the corresponding block data for compression transmission; A visualization window construction unit is configured to construct a three-dimensional visualization window; the three-dimensional visualization window is configured to: after the target user clicks a viewpoint tag, parse the target viewpoint of the target user, and receive compressed block data for data parsing and batch rendering; A collaborative system construction unit is used to build a blockchain collaborative system; the blockchain collaborative system is configured to: create an enterprise-level private chain, create roles and assign contract permissions based on the identity information of the target user in the private chain; record the target user's operation log and generate a hash value, and splice each operation log of the target user to form an irreversible chain structure; A management network construction unit is used to build a viewpoint management network; the viewpoint management network is configured to: set a new button in the 3D visualization window to create and save viewpoint tags, set a collaborative sharing button to transfer and coordinate viewpoint tags; and preload frequently accessed viewpoint tags based on a user behavior prediction model; The roaming animation construction unit is used to build a roaming animation output network; the roaming animation output network is configured to: dynamically allocate animation time to each viewpoint tag in the viewpoint tag set and smooth the roaming animation path; and trace rays in real time to output the roaming animation.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to perform the steps of the viewpoint-based railway BIM visualization processing method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the steps of the viewpoint-based railway BIM visualization processing method according to any one of claims 1 to 7 when executed.

Images