Digital city design city model visual display system

Abstract

The application relates to the technical field of three-dimensional rendering, in particular to a digital city design city model visual display system, which comprises a use calibration module, a component combination module, a path guiding module, a visual angle scheduling module and a rendering display module. In the application, through optimization of use calibration in city space and detailed processing of geographic information, more accurate visual performance of the use of the city model space is realized, through dynamic adjustment of the anchor point of the use space, more reasonable space utilization distribution and visual display are realized, more intelligent decision making in city planning and building design is supported, through extraction and combination of building components with different functions, the functional semantic expression of the model is further strengthened, the information value and practicability of the model are enhanced, the interactivity and educational significance of the model are strengthened, and the improvement of the rendering display makes the model more realistic in vision and more capable of accurately reflecting the appearance of a real city, thereby improving the display quality and attraction of the model.

Description

Technical Field

[0001] This invention relates to the field of 3D rendering technology, and in particular to a digital urban design city model visualization system. Background Technology

[0002] The field of 3D rendering technology encompasses various methods and techniques for generating, manipulating, and displaying 3D models and environments using computer software and hardware resources. The core of this field involves converting abstract data models into visually experiential graphical output, primarily achieved through techniques such as ray tracing, texture mapping, and shadow generation. A systematic overview of this technology includes 3D modeling, material and texture design, animation production, scene lighting processing, and rendering output—all processes working together to generate realistic 3D visual effects.

[0003] The digital urban design city model visualization system refers to the use of 3D rendering technology to create and display detailed digital models of urban planning and architectural designs. This technical aspect involves constructing comprehensive urban geographic information system data, 3D building models, and urban infrastructure models. Through data and models, the system can generate and display detailed views of the city in a virtual environment, involving spatial data processing and 3D visual display technologies. In this way, the system provides a tool to support urban planners and architects in making more informed decisions during the design and planning process.

[0004] Existing technologies neglect the detailed layering and optimization of spatial use and functional semantics when processing urban models. This results in models that, while morphologically accurate, lack precision and practicality in terms of usage distribution and functional representation. This approach limits the practical application value of the models, making it difficult to effectively support complex urban planning and decision-making processes. The path guidance and viewpoint scheduling in existing technologies are not intelligent enough, impacting the user's navigation experience and visual acceptance in the virtual environment, hindering the effective extraction of necessary information from the model. Common problems with existing rendering techniques when handling complex urban scenes include improper layer processing and unnatural viewpoint transitions, directly affecting the final model's presentation and user experience, significantly diminishing its educational and demonstrative functions. Summary of the Invention

[0005] To address the shortcomings of existing technologies that neglect detailed layering of usage space and functional semantics, resulting in models that, while morphologically accurate, lack precision and practicality in usage distribution and functional expression, this approach limits the practical application value of the models and makes it difficult to effectively support complex urban planning and decision-making processes. Existing technologies lack intelligent path guidance and viewpoint scheduling, impacting the user's navigation experience and visual acceptance in the virtual environment, hindering the effective extraction of necessary information from the model. Common problems with existing rendering techniques when handling complex urban scenes include improper layer processing and unnatural viewpoint switching, directly affecting the final model's display effect and user experience, significantly diminishing the model's educational and demonstrative functions. This invention provides a digital urban design city model visualization system. The technical solution is as follows:

[0006] On the one hand, a digital urban design city model visualization system is provided, which includes:

[0007] The usage identification module acquires standard usage units in urban space, records the occurrence information of each usage in the unit, transforms the records into a spatial distribution structure, identifies the orientation relationship of unit anchor points, and rebinds them with usage labels to obtain the spatial usage anchor point layer structure.

[0008] Based on the spatial use anchor point layer structure, the component combination module extracts three-dimensional building components from the city model, classifies the functional semantic tags of the three-dimensional building components, and combines and arranges the spatial layout of the components to obtain a semantic component assembly display unit.

[0009] The path guidance module assembles display units based on the semantic components, extracts the associated landmark node information, detects the guidance relationship between adjacent landmarks according to the order of nodes in the path advancement, and filters the display priority of the node sequence in the continuous guidance direction to obtain the path stage display sequence.

[0010] Based on the path-stage display sequence, the view scheduling module analyzes the view relationships of key nodes in the path, identifies the occlusion structure and orientation continuity of adjacent landmarks in the path, and performs directional scheduling of display views for nodes with occlusion and directional deviation to obtain a continuous view switching node group.

[0011] As a further embodiment of the present invention, the spatial purpose anchor point layer structure includes anchor point offset trajectory within the purpose boundary, anchor point purpose label binding relationship, and anchor point spatial hierarchy distribution; the semantic component assembly display unit includes component assembly layout block, component semantic label mapping relationship, and component linkage sequence node chain; the path stage display sequence includes display path node index set, path advancement direction sequence, and landmark guidance level mark group; and the continuous view switching node group includes continuous viewable node pairs, view direction adjustment mark group, and occlusion relationship determination mark set.

[0012] As a further aspect of the present invention, the application calibration module includes:

[0013] The submodule for constructing use units acquires standard use units in urban space, collects the types of use tags within standard use units, categorizes and records the occurrence of the same use in multiple units, performs use division and aggregation operations on units, and generates use distribution classification information.

[0014] Based on the application distribution classification information, the boundary contour recognition submodule extracts the spatial boundary region for each application, calls the graphic contour data of the closed structure in the boundary region, compares the coordinate set of the contour node positions in the closed contour, identifies the boundary group with continuous closed features, and generates a set of closed contours for application boundaries.

[0015] The anchor point direction determination submodule extracts the marked anchor point positions within the application boundary based on the closed contour set of the application boundary, calls the spatial direction vector between the anchor point and the center point of the boundary, performs an angle range division operation on the distribution trend of the spatial direction vector, and generates a set of anchor points with consistent direction.

[0016] The purpose binding adjustment submodule calls the set of anchor points with consistent direction, performs spatial position correction towards the center on the position structure of the anchor points within the boundary, and re-matches the purpose tag category to the corrected anchor points to obtain the spatial purpose anchor point layer structure.

[0017] As a further aspect of the present invention, the re-matching of the usage label category to the corrected anchor point adopts the formula:

[0018] ;

[0019] in, Representing the Anchor point usage tag matching deviation value for usage category tag. Represents the total number of anchor points. Representing the The first under the class tag Corrected spatial displacement distance of each anchor point Representing the The first under the class tag Spatial association weight coefficient between each anchor point and the center of the usage category. and Representing the first The first under the class tag The coordinates of each anchor point in the horizontal and vertical directions. Representing the Reference value for the center position of the class / purpose category in two-dimensional space. Representing the The class label is expected to match a stable constant.

[0020] As a further aspect of the present invention, the component assembly module includes:

[0021] The component extraction and identification submodule extracts urban 3D model components associated with the spatial use anchor point layer structure based on the spatial use anchor point area, compares the spatial location data of the urban 3D model components in the model with the component identification code, identifies the usage area of ​​the urban 3D model components in the urban model, and generates component usage association information.

[0022] The tag semantic classification submodule calls the functional semantic tags of the urban 3D model components according to the component usage association information, divides and organizes the tag information according to the component type, performs the main tag extraction operation on components with multiple overlapping tags, and generates a functional tag mapping set.

[0023] The component process filtering submodule calls the function tag mapping set, identifies the design process call order between function tags, sorts the components with continuous call relationships by number, and cross-validates with the purpose attribution data between components. It then filters the component combination nodes with consistent function tags and adjacent process order to obtain continuous grouping records of component processes.

[0024] The combined layout submodule calls the component process to continuously group and record, detects the spatial layout boundary of the components within the component group, determines the positional relationship between the boundaries, adjusts the position of components with spatial overlap and re-records the layout status, and integrates the coordinate information of the components in the layout with the functional semantics to obtain the semantic component assembly display unit.

[0025] As a further aspect of the present invention, the path guidance module includes:

[0026] The landmark node extraction submodule extracts landmark components from the associated path advancement nodes based on the semantic component assembly and display unit, synchronously merges the position index and functional semantics of the landmarks in the component group, evaluates the bidirectional matching degree of the path node and landmark correspondence, and obtains the path landmark matching index group.

[0027] The visual feature collection submodule identifies the usage category information of the path landmarks, constructs hierarchical attributes and identifies appearance features based on the path landmark matching index group, classifies and integrates the visual feature labels of the landmarks, and performs structured sorting processing on the usage category and hierarchical data to obtain the landmark feature structure sequence.

[0028] The guidance relationship detection submodule calls the landmark feature structure sequence, extracts the connection direction vector between adjacent nodes according to the node numbering order in the path advancement, detects the orientation continuity between continuous nodes and the change status of landmark label type, and marks the landmark node sequence with the same direction and unchanged label as a continuous guidance path segment to obtain the landmark connection sequence identifier.

[0029] The priority filtering and sorting submodule calls the landmark connection sequence identifier, extracts the display order number of the path segment and the landmark structural feature level, compares and filters the display priority of path segments with structural hierarchy advantages and connection stability, and performs sorting update according to visual extension relationship to obtain the path stage display sequence.

[0030] As a further aspect of the present invention, the display sequence number and landmark structure feature level of the extracted path segments are determined using the following formula:

[0031] ;

[0032] in, R represents the priority value for displaying path segments. a The structural feature level score represents the a-th landmark. The index representing the connection stability of the b-th path segment is... This represents the local position coefficient of the a-th landmark under the k-th visual extension direction. This represents the proportion of the mapped length of the b-th path segment under the k-th visual extension direction. This represents the average display weight of the combination of the a-th landmark and the b-th path segment. represents the standard deviation of the display weights of the combination of the a-th landmark and the b-th path segment in the sample statistics, and N represents the total number of visual extension directions.

[0033] As a further aspect of the present invention, the view scheduling module includes:

[0034] The perspective node analysis submodule extracts key nodes in the path advancement based on the path stage display sequence, calls the spatial coordinate data and path connection relationship corresponding to the key nodes, divides the monitoring angle between nodes into intervals, constructs the perspective extension direction map between nodes, and generates path perspective association structure group.

[0035] The occlusion relationship recognition submodule extracts the occlusion distribution of components between nodes based on the path view associated structure group, calls the facade outline and spatial height information of the three-dimensional components, performs position intersection determination on component areas with overlapping boundaries, and marks the occlusion degree level of the corresponding path nodes to obtain the node occlusion status determination result.

[0036] The viewpoint direction adjustment submodule calls the node occlusion status determination result, filters the set of nodes marked as having deviation in occlusion level, compares the angle between the real-time viewpoint direction and the path forward direction, and if there is a deviation in direction, performs repositioning of the node monitoring direction, updates the node viewpoint pointing attribute, and obtains the display node viewpoint adjustment group.

[0037] As a further aspect of the present invention, the system also includes a rendering and display module:

[0038] The rendering and display module switches node groups according to the continuous viewpoint, extracts component layers and usage marking areas in the city model, performs layer sorting operations in combination with the path advancement sequence, constructs a visual overlay order according to the landmark structure hierarchy, performs sequential rendering of component layers, and performs projection processing on the usage layer, landmark structure and combined component layer to obtain a set of city model visualization rendering views.

[0039] The city model visualization rendering view set includes a layer rendering sort table, a combined layer overlay index, and projection results of the usage and component layers.

[0040] As a further aspect of the present invention, the rendering and display module includes:

[0041] The layer element extraction submodule extracts the urban component layer covered by the path node based on the continuous view switching node group, calls the spatial location index data of the components and the use marking area in the layer, locates the layout position and display range of the urban component layer in the view, analyzes the relationship structure between the use area layer and the component layer in the path node, and generates a set of layer display elements.

[0042] The layer order construction submodule, based on the set of elements displayed by the layers, calls the node sequence information of the path advancement, numbers and collects the order of appearance of the layers in the path advancement process, and generates a layer sorting structure index.

[0043] The view rendering submodule calls the visual overlay display order set, groups the component layer, purpose layer and landmark structure layer in the path node in a unified manner according to the display order, performs layer combination mapping operation and performs path dynamic projection on the combined layer structure to obtain the city model visualization rendering view set.

[0044] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0045] By optimizing the spatial usage identification and meticulous processing of geographic information in urban spaces, a more accurate visualization of urban model spatial uses is achieved. Dynamically adjusting the anchor points of spatial uses enables a more rational distribution and visual presentation of space utilization, supporting more informed decision-making in urban planning and architectural design. Extracting and combining architectural components with different functions further enhances the model's functional semantic expression, making it more than just a collection of shapes; it provides clear functional indications, increasing its informational value and practicality. Introducing path guidance and perspective manipulation techniques effectively optimizes the user's navigation experience and visual acceptance, ensuring users receive coherent and clear visual information in the virtual environment. This strengthens the model's interactivity and educational value. Improved rendering makes the model visually more realistic, accurately reflecting the appearance of real cities and enhancing its presentation quality and appeal. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of a digital urban design city model visualization display system provided in an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of the system framework of the present invention;

[0049] Figure 3 This is a flowchart of the application calibration module in this invention;

[0050] Figure 4 This is a flowchart of the component assembly module in this invention;

[0051] Figure 5 This is a flowchart of the path guidance module in this invention;

[0052] Figure 6 This is a flowchart of the view scheduling module in this invention;

[0053] Figure 7 This is a flowchart of the rendering and display module in this invention. Detailed Implementation

[0054] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0055] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0056] In the embodiments of this invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning. Similarly, the terms "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning.

[0057] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0058] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0059] This invention provides a digital urban design city model visualization system, such as... Figure 1-2 The diagram shown illustrates a digital urban design city model visualization system. This system includes:

[0060] The usage identification module acquires standard usage units in urban space, records the occurrence information of each usage in the unit, transforms the records into a spatial distribution structure, calls the closed contour of the boundary area of ​​multiple usages, identifies the orientation relationship of unit anchor points, performs center offset adjustment on anchor points with consistent orientations, and rebinds them with usage labels to obtain the spatial usage anchor point layer structure.

[0061] The component assembly module is based on the spatial use anchor point layer structure. It extracts three-dimensional building components from the city model, classifies the functional semantic tags of the three-dimensional building components, filters component clusters with matching tags and continuous flow, and combines and arranges the spatial layout of the components to obtain semantic component assembly display units.

[0062] The path guidance module assembles display units based on semantic components, extracts the associated landmark node information, collects the landmark's usage category, visual recognition features and display weight ranking, detects the guidance relationship between adjacent landmarks according to the order of nodes in the path advancement, and filters the display priority of the node sequence in the continuous guidance direction to obtain the path stage display sequence.

[0063] The view scheduling module is based on the path stage display sequence. It analyzes the view relationship of key nodes in the path, identifies the occlusion structure and orientation continuity of adjacent landmarks in the path, performs directional scheduling of display view for nodes with occlusion and orientation deviation, verifies the first and last nodes of the continuous visible path segment, and obtains the continuous view switching node group.

[0064] The rendering and display module switches node groups based on continuous viewpoints, extracts component layers and usage marking areas from the city model, sorts layers in combination with path progression sequence, constructs visual overlay order based on landmark structure hierarchy, renders component layers in sequence, and performs projection processing on usage layers, landmark structures and combined component layers to obtain a set of city model visualization rendering views.

[0065] The spatial use anchor point layer structure includes the anchor point offset trajectory within the use boundary, the anchor point use label binding relationship, and the spatial hierarchy distribution of anchor points. The semantic component assembly display unit includes component combination layout blocks, component semantic label mapping relationship, and component linkage sequence node chain. The path stage display sequence includes the display path node index set, path advancement direction sequence, and landmark guidance level marker group. The continuous view switching node group includes continuous viewable node pairs, view direction adjustment marker group, and occlusion relationship judgment annotation set. The city model visualization rendering view set includes the layer rendering sorting table, combined layer overlay index, and use and component layer projection results.

[0066] Specifically, such as Figure 2 , 3 As shown, the application calibration module includes:

[0067] The submodule for constructing use units acquires standard use units in urban space, collects the types of use tags within standard use units, categorizes and records the occurrence of the same use in multiple units, performs use division and aggregation operations on units, and generates use distribution classification information.

[0068] The basic grid units of urban space are determined by dividing the target area into equilateral regular grids based on the city's geographical boundaries. Each unit serves as the smallest unit of analysis. POI data or geographic entity layers from the city are imported, and the system traverses the geographic objects within each grid unit, identifying their usage tags, such as "residential," "office," and "commercial." The frequency and density of the same usage type appearing in different units are categorized and statistically analyzed to form a usage frequency list. The types and quantities of usage tags appearing in each unit are recorded. During the operation, to ensure the accuracy of tag classification, preliminary classification is required based on the concentration of tags in each unit. Units with high frequency of commercial uses are identified as commercial areas. The system performs tag aggregation on units and determines the tags corresponding to the primary uses to complete unit usage identification. Taking a city as an example, if a certain area has a dense distribution of shopping malls, restaurants, cafes, convenience stores, etc., then that area is designated as the primary tag for commercial use, while also accommodating residential and office as secondary uses, generating usage distribution classification information.

[0069] The boundary contour recognition submodule extracts the spatial boundary region for each type of use based on the usage distribution classification information, calls the graphic contour data of closed structures in the boundary region, compares the coordinate sets of the contour node positions in the closed contour, identifies the boundary group with continuous closed features, and generates a set of closed contours for the usage boundary.

[0070] The system accurately extracts contiguous spatial areas with the same purpose, reads units under each purpose category, determines whether they are adjacent based on their location coordinates, and delineates connected units into the same spatial group, forming a boundary area set. The system analyzes the spatial coverage edge in the boundary area set and extracts the outer contour shape of the area. It constructs a closed boundary recognition path by processing the closed shape contour in the layer. In this process, it also needs to compare the node coordinates of the closed shape. When the node structure of multiple shapes has a high degree of overlap or similar arrangement rules, it can be determined as a continuous closed boundary set. Taking urban green space recognition as an example, when multiple units with the "green space" label gather together, the system recognizes it as a complete urban park area and extracts its outer contour through the spatial connectivity of the contour nodes, forming a complete closed boundary set. The system uniformly numbers and marks this set to ensure that each closed structure can be called and located by subsequent modules, generating a closed contour set of purpose boundaries.

[0071] The anchor point direction determination submodule extracts the marked anchor point positions within the application boundary based on the closed contour set of the application boundary, calls the spatial direction vector between the anchor point and the center point of the boundary, performs an angle range division operation on the distribution trend of the spatial direction vector, and generates a set of anchor points with consistent direction.

[0072] To clarify the spatial distribution direction of anchor points for each use within a closed boundary area, it is necessary to extract the marked positions of anchor points from the already classified use boundaries. Anchor points represent key buildings or landmarks, such as large shopping malls, office buildings, or schools within a certain area, and are defined as anchor point elements in the system. The directional relationship between the anchor point and the center of its boundary is calculated, and the azimuth angle of each anchor point relative to the center is recorded. By comparing the spatial distribution trend of anchor points, anchor points with the same or similar orientations are grouped together. For example, in a large residential community, if most anchor points are concentrated in the northeast corner of the area, the system identifies this direction as the main direction of anchor point distribution and marks it as a "directionally consistent" anchor point set. This process is very common in urban function analysis, especially suitable for identifying the distribution of direction-oriented urban facilities, such as office areas densely distributed towards the city center, and commercial areas extending along main roads. The anchor point set formed after direction determination will serve as an important basis for subsequent use binding adjustments, helping to enhance the overall expressive accuracy of the urban spatial model and generate a directionally consistent anchor point set.

[0073] The purpose binding adjusts the set of anchor points with the same calling direction as the submodule. The spatial position of the anchor points within the boundary is corrected towards the center. The corrected anchor points are then rematched with the purpose tag category to obtain the spatial purpose anchor point layer structure.

[0074] Rematch the usage label category to the corrected anchor points using the formula:

[0075] ;

[0076] in, Representing the Anchor point usage tag matching deviation value for usage category tag. Represents the total number of anchor points. Representing the The first under the class tag Corrected spatial displacement distance of each anchor point Representing the The first under the class tag Spatial association weight coefficient between each anchor point and the center of the usage category. and Representing the first The first under the class tag The coordinates of each anchor point in the horizontal and vertical directions. Representing the Reference value for the center position of the class / purpose category in two-dimensional space. Representing the Class label expected to match stable constants;

[0077] Meaning of parameters and derivation of formulas:

[0078] Parameter acquisition and value setting:

[0079] : Through the first The number of anchor points under the category / purpose tag is calculated;

[0080] The spatial displacement of the anchor point before and after correction is measured using a high-precision GPS device, with the unit being meters. The displacement of a certain anchor point is 2.5 meters.

[0081] The calculation is based on the spatial correlation between the anchor point and the center of the usage category, using an inverse distance weighting model. The weight calculation formula is as follows:

[0082] ;

[0083] in, A tiny constant, set to 0.0001, is used to prevent division by zero errors.

[0084] The latitude and longitude coordinates of anchor points are obtained through GIS equipment and converted into planar coordinates in meters. The coordinates of a given anchor point are... rice, rice;

[0085] : By calculating the first The center position is obtained by averaging the coordinates of the anchor points under the category / purpose tag. rice;

[0086] Based on data analysis, the expected matching stable constants are set.

[0087] Formula calculation process:

[0088] For the Class-specific labels are used to calculate the matching deviation value for each anchor point, and the absolute value of the difference between the average value and the expected stable constant of matching is calculated.

[0089] Taking the first anchor point as an example:

[0090] Calculate the weights:

[0091] ;

[0092] Calculate the coordinate difference:

[0093] ;

[0094] Calculate the square root of the denominator:

[0095] ;

[0096] Calculate the numerator:

[0097] ;

[0098] Calculate the matching value for this anchor point:

[0099] ;

[0100] The same calculation was performed on the 5 anchor points, and the resulting matching values ​​were set to 0.0179, 0.0201, 0.0195, 0.0187, and 0.0210, respectively.

[0101] Calculate the average match value:

[0102] ;

[0103] Calculate the matching deviation value:

[0104] ;

[0105] This result indicates that the current set of anchor points is similar to the first... The matching deviation value of the purpose label is 0.0306, which is used to measure the difference between the current label of the anchor point and the label it should have. It indicates the inconsistency between the purpose label assigned to an anchor point and the purpose label that should correspond to the actual location or feature. It indicates that there is a certain degree of deviation between the anchor point set and the expected purpose label. This value can be used to evaluate the matching quality of the anchor point set and guide the optimization and adjustment of the subsequent spatial purpose anchor point layer structure.

[0106] Specifically, such as Figure 2 , 4 As shown, the component assembly module includes:

[0107] The component extraction and identification submodule extracts urban 3D model components associated with spatial use anchor point layer structure based on spatial use anchor point area, compares the spatial location data of urban 3D model components in the model with component identification code, identifies the usage area of ​​urban 3D model components in urban model, and generates component usage association information.

[0108] The system reads the spatial use anchor point layer structure and imports the location coordinates of each anchor point into a matching 3D city model environment. It then extracts building components corresponding to the coordinate range from the model. Each component has a unique component code and model location parameters in the 3D model. The system performs a preliminary identification of whether a component belongs to a certain use area by cross-referencing the coordinate range with the code. During the identification process, the system traverses the component's location data to determine if it falls within the spatial range corresponding to a certain anchor point layer. If it does, it is classified into that use area. Taking a mixed-use building as an example, which includes residential, commercial, and office spaces, the system marks its residential entrance and commercial podium entrance using spatial use anchor points. The system identifies multiple components in the podium, such as elevators, stairs, and exterior glass, all of which are located in the area corresponding to the commercial anchor point, thus belonging to the commercial use area. After identification, the system records the code, coordinates, and usage label of each component, generating component usage attribution association information.

[0109] The tag semantic classification submodule calls the functional semantic tags of the city 3D model components based on the component usage and association information, divides and organizes the tag information according to the component type, performs the main tag extraction operation on components with multiple overlapping tags, and generates a functional tag mapping set.

[0110] The system retrieves the original semantic tags attached to each component in the city's 3D model. These tags are typically preset by the design unit or modeling platform and include names, functional attributes, and category information. The system organizes and categorizes these tags according to component type, separating components such as doors and windows, walls, elevators, and air conditioners. For components with overlapping tags, such as a component labeled as "public passage" and "emergency exit," the system needs to perform a primary tag extraction operation to identify the most representative or frequently used tag. The judgment criteria can be comprehensively evaluated based on dimensions such as the frequency of tag distribution in the component and the weight of its usage. The tag that best matches the current usage characteristics of the component is selected as the primary tag. For example, in an office building model, the lobby component tags include three semantic meanings: "entrance," "reception," and "waiting." By analyzing the tag distribution of similar lobby components, the system finds that the "reception" tag has a wider coverage and higher usage frequency, and therefore selects it as the primary tag. The component will be classified into the functional dimension corresponding to its primary semantic tag, forming a functional tag mapping set.

[0111] The component process filtering submodule calls the function tag mapping set, identifies the design process call order between function tags, sorts the components with continuous call relationships by number, and cross-validates with the purpose attribution data between components. It then filters the component combination nodes with consistent function tags and adjacent process order to obtain continuous grouping records of component processes.

[0112] The system identifies the calling order between execution components, analyzes the sequential logic between functional labels in the actual usage process, such as "entrance" corresponding to "reception" and "reception" corresponding to "access", and identifies the continuous relationship between each component in the design or use process. Whenever two labels are found to be logically connected and the spatial components are adjacent in the model, the system marks them as a continuous calling relationship. In this process, the system also compares the component's purpose attribution label to ensure that the two components are not only semantically connected, but also in the same or similar purpose area. In a commercial complex, the entrance door component and the lobby component both belong to the commercial use area and have logically connected semantic labels. The system marks them as a continuous process combination, assigns a number to each combination node to indicate its process execution order, and then compares and verifies this sorting information with the space use record. Component combinations with adjacent processes and consistent functions are filtered to obtain the continuous grouping record of component processes.

[0113] The combined layout submodule calls the component process continuously grouped and recorded, detects the spatial layout boundary of the components within the component group, performs staggered judgment on the positional relationship between the boundaries, adjusts the position of components with spatial overlap and re-records the layout status, and integrates the coordinate information of the components in the layout with the functional semantics to obtain the semantic component assembly display unit.

[0114] The system identifies and processes the spatial arrangement of components within a group, analyzing the boundary information of each component, i.e., the spatial occupancy of the component in the 3D model, including length, width, and height. By reading the model coordinates and boundary frames, the system determines the arrangement relationship between components. For components with spatial overlap or positional overlap, the system performs position adjustment operations to ensure that the components are arranged reasonably without overlap. During the processing, the system scans the relative position of each component within the group with its adjacent components. When it is determined that a component is located inside the space of another component or at the boundary intersection, it is moved outward a certain distance. After the adjustment is completed, its coordinate position in the model is updated. Taking a group of components labeled "Business Reception Process" as an example, if the boundaries of the lobby and passageway components overlap, the system performs a spatial outward offset operation on the passageway components to avoid duplicate arrangement. After the component positions are adjusted and confirmed to be non-overlapping, the system integrates the component coordinate data with its main semantic tag to obtain a semantic component assembly display unit.

[0115] Specifically, such as Figure 2 , 5 As shown, the path guidance module includes:

[0116] The landmark node extraction submodule extracts landmark components from the associated path advancement nodes based on the semantic component assembly and display unit. It synchronously merges the position index and functional semantics of the landmark in the component group, evaluates the bidirectional matching degree of the path node and landmark correspondence, and obtains the path landmark matching index group.

[0117] The system filters and identifies landmark components within a group of components. These components have prominent locations, clear functional labels, or visual identifiers in their design, such as large entrance structures, iconic sculptures, and uniquely shaped roofs. The system then maps these components to key locations within the path progression nodes to determine which components can serve as landmarks along the path. During operation, the system reads the component's index position within the assembly unit and, combined with its functional labels, identifies components with high spatial orientation or recognizability as candidate landmarks. The system aligns the spatial position of each candidate component with the path progression node number, evaluating whether it spatially matches the path node position. If a landmark component appears repeatedly in multiple path progression nodes, the system merges its position index and records it in the path landmark matching index table. For example, in a commercial complex where multiple nodes revolve around the same central hall component, the system marks this hall as a frequently occurring path landmark, merges its spatial indices across different path segments, completes a two-way matching degree evaluation, and obtains a path landmark matching index group.

[0118] The visual feature collection submodule identifies the usage category information of the path landmarks, constructs hierarchical attributes and identifies appearance features based on the path landmark matching index group, classifies and integrates the visual feature labels of the landmarks, and performs structured sorting processing on the usage category and hierarchical data to obtain the landmark feature structure sequence.

[0119] The system identifies the usage category of each path landmark and further extracts its structural hierarchy attributes, determining whether it is located at the main entrance of a building, a secondary corridor, or a top component. Simultaneously, the system reads and processes the appearance features of the components, including predefined visual label information such as color, material, and shape. Components with similar visual labels are categorized and integrated. If multiple landmark components share the labels "glass material" and "triangular roof," they are grouped into a unified appearance feature category. The system combines the labels to form a visual feature set and then constructs a structured sort based on usage category and hierarchy attributes, prioritizing components with higher hierarchical levels. For example, in a path, the main entrance component of an office building, possessing the characteristics of "main building structure" and "central axis symmetry," will be prioritized for a higher-level sorting position. The system records the visual feature label group, usage category identifier, and structural hierarchy information of each landmark to facilitate subsequent continuous identification and guiding logic judgment of node paths, resulting in a landmark feature structure sequence.

[0120] The guidance relationship detection submodule calls the landmark feature structure sequence, extracts the connection direction vector between adjacent nodes according to the node numbering order in the path advancement, detects the orientation continuity between continuous nodes and the change status of landmark label type, and marks the landmark node sequence with the same direction and unchanged label as a continuous guidance path segment to obtain the landmark connection sequence identifier.

[0121] The system analyzes and processes the node sequence in the path progression. It reads the node number and the position of its adjacent nodes in space, extracts their spatial connection direction, and sets a judgment to determine whether two nodes are advancing in the same direction in space. The system lists nodes with the same direction as a continuous path segment. During the recognition process, it also needs to determine whether the landmark components associated with the nodes are consistent in semantic labels. For example, if the landmarks pointed to by two consecutive nodes in the path are both of the "main entrance" category and have the same spatial orientation, the system marks the path segment as a continuous guiding path segment. For example, if in an exhibition hall, the path extends from the main entrance to the atrium and then guides to the exhibition hall, and each node is based on an "entrance-type component" as the main landmark and extends along the main passage, the system identifies it as a continuous guiding path. At the same time, the system also records the nodes with changed labels to distinguish node pairs that are directionally connected but have changed functions, forming a landmark connection sequence identifier.

[0122] The priority filtering and sorting submodule calls the landmark connection sequence identifier, extracts the display order number of the path segment and the landmark structural feature level, compares and filters the display priority of path segments with structural hierarchy advantages and connection stability, and performs sorting and updating according to the visual extension relationship to obtain the path stage display sequence.

[0123] Extract the display sequence number and landmark structure feature level of the path segment using the formula:

[0124] ;

[0125] in, R represents the priority value for displaying path segments. a The structural feature level score represents the a-th landmark. The index representing the connection stability of the b-th path segment is... This represents the local position coefficient of the a-th landmark under the k-th visual extension direction. This represents the proportion of the mapped length of the b-th path segment under the k-th visual extension direction. This represents the average display weight of the combination of the a-th landmark and the b-th path segment. represents the standard deviation of the display weights of the combination of the a-th landmark and the b-th path segment in the sample statistics, and N represents the total number of visual extension directions;

[0126] Meaning of parameters and derivation of formulas:

[0127] Landmark structure feature level score R a The recognition rate is obtained based on the quantitative standard of building structural complexity and landmark recognizability level. It is scored by combining the recognition success rate collected in on-site visual recognition tests with a facade structural complexity grading model. In the current case, the a-th landmark is a tower building with a structural complexity level of 3. Its recognizability rates in close-up, mid-range, and long-range views are 0.92, 0.85, and 0.60, respectively. The comprehensive recognition index is calculated using weighted averages, with close-up weighting at 0.5, mid-range weighting at 0.3, and long-range weighting at 0.2. Therefore, the comprehensive recognition rate is:

[0128] ;

[0129] The path segment connectivity stability index Lᵦ is calculated using a comprehensive quantitative standard based on the stability of connecting nodes, the consistency rate of path direction, and the path accessibility level in GIS. The connecting node stability is 0.88, the consistency rate of direction is 0.75, and the accessibility level is assigned a value of 0.9. Based on the coefficient weighting ratios of 0.4, 0.3, and 0.3 respectively, then:

[0130] ;

[0131] Landmark local location coefficient α ak The visible aperture ratio in each direction k is obtained through three-dimensional spatial orientation distribution detection. Multiplying this by the orientation significance factor, the current landmark has aperture ratios of 0.80, 0.65, and 0.50 in the three directions k1, k2, and k3, respectively, corresponding to significance factors of 1.2, 1.0, and 0.9.

[0132] ;

[0133] ;

[0134] ;

[0135] The proportion of the mapped length of the path segment in the visual extension direction dᵦ k Based on the ratio of the projected length of the path segment to the maximum extension length in each direction, the projected lengths of the path segment in directions k1, k2, and k3 are 15 meters, 10 meters, and 6 meters, respectively, and the corresponding maximum extension lengths in those directions are 20 meters, 12 meters, and 10 meters. Therefore:

[0136] ;

[0137] ;

[0138] ;

[0139] Combined average display weight μa ᵦ and display weight standard deviation δ a ᵦ are all derived from the visualized behavioral statistics records of landmark-path segment combinations over multiple time periods, μ a ᵦ is 0.68, δ a ᵦ is 0.12;

[0140] Substitute the above data into the formula to perform the calculation:

[0141] ;

[0142] ;

[0143] Substitute into the formula to calculate:

[0144] ;

[0145] The results show that the priority display value of the combination of landmark a and path segment b is 13.5487, which is used to determine the order and importance of different path segments in a certain visual or information display. It belongs to the high weight range. This value can be used as a priority display reference benchmark when updating the ranking. Its high value reflects that the combination has significant structural hierarchy advantages, connection stability and visual extension direction coupling strength, and has a strong driving effect on the path stage display sequence.

[0146] Specifically, such as Figure 2 , 6 As shown, the viewpoint scheduling module includes:

[0147] The perspective node analysis submodule extracts key nodes in the path advancement based on the path stage display sequence, calls the spatial coordinate data and path connection relationship corresponding to the key nodes, divides the monitoring angle between nodes into intervals, constructs the perspective extension direction map between nodes, and generates path perspective association structure group.

[0148] The system extracts key nodes identified in the path progression, categorized as scene turning points, path connection points, or nodes with visual cues. It retrieves the spatial coordinates of these key nodes and, combined with their preceding and following node numbers within the path segment, constructs the path connection relationships between nodes. The system analyzes the angle of view between each pair of adjacent key nodes, assessing the relationship between the observation direction and the path progression direction based on spatial coordinates. The angle is divided into intervals according to actual values, such as smaller angles for straight sections and larger angles for turning sections, facilitating subsequent differentiation of the view extension trends between nodes. By summarizing the spatial connection directions between multiple nodes, the system generates a map containing directional relationships, recording the view extension directions between each node. For example, in a shopping mall path node, where preceding and following nodes form a 90-degree angle, the system records a significant view deflection at that node and associates it with the directional map between path segments. This prepares for subsequent node occlusion identification and adjustment, generating a path view association structure group.

[0149] The occlusion relationship recognition submodule associates the structural groups based on the path perspective, extracts the occlusion distribution of components between nodes, calls the facade contour and spatial height information of the three-dimensional components, performs position intersection determination on component areas with overlapping boundaries, and marks the occlusion degree level of the corresponding path nodes to obtain the node occlusion status determination result.

[0150] The system locates the path view segment between each pair of adjacent nodes and reads the 3D component data in that view direction, mainly including the facade outline and spatial height information of the components. During the recognition process, the system compares the position of each component in space with the line of sight extension to check whether the component forms an obstruction within the line of sight. If two components have an overlapping boundary area in the projection range, the system judges it as a potential obstruction source. Then, based on the component height level and positional relationship, it further confirms the degree of obstruction. In a street path segment, if a billboard component is in front of the line of sight and higher than the observation view, the system marks the billboard as the main obstruction component and applies an obstruction level to the current node, such as "medium level obstruction" or "severe obstruction". The system will sequentially mark the obstruction status of each path node, including the obstruction source component, the obstruction area range, the degree of impact, etc., to form the node obstruction status judgment result.

[0151] The viewpoint direction adjustment submodule calls the node occlusion status judgment result, filters the set of nodes marked as having deviation in occlusion level, compares the angle between the real-time viewpoint direction and the path forward direction, and if there is a deviation in direction, performs repositioning of the node monitoring direction, updates the node viewpoint pointing attribute, and obtains the display node viewpoint adjustment group.

[0152] Path nodes marked as having deviations are extracted. These nodes' original viewing direction may be inconsistent with the path's direction of travel, or their observation may be offset due to occlusion. The system re-evaluates the node's viewing direction by comparing the angle between its current viewing direction and the forward direction. If the angle is significantly off, the system adjusts the node's viewing attributes and resets the monitoring or observation direction. During adjustment, the system prioritizes an unobstructed direction that covers the path's extension area as the new viewing target and updates the node's viewing vector information in the path view structure. In a traffic hub simulation scenario, a path node's original direction is obstructed by a nearby advertising tower. After re-comparing the path's extension direction, the system shifts the node's monitoring direction to a slightly left, unobstructed area and simultaneously updates the node's viewing attributes in the component layer. All adjusted nodes are then grouped together for subsequent determination of continuous visible path segments, resulting in a display node viewing adjustment group.

[0153] The line-of-sight path verification submodule calls the display node view adjustment group to evaluate the consistency of view direction and the stability of occlusion attributes in continuous nodes. It records the start and end marks of path segment nodes with continuous direction and no occlusion characteristics, and integrates the first and last nodes of qualified segments to form display node pairs, thus obtaining a continuous view switching node group.

[0154] The system performs directional consistency and occlusion stability verification on continuous path segments. It checks each adjusted path node one by one, compares the viewing directions between adjacent nodes to ensure continuity and no obvious jumps in the extension direction, and checks again for new occlusion risks in the directions pointed to by each node in the path segment. If the directions between nodes in a certain path segment are consistent and the corresponding components have no obstruction in their line of sight, the system marks the path segment as a visible path segment. Each qualified path segment is recorded with its start and end point numbers and organized into display node pairs, forming a continuously switchable view node group. Taking a city navigation scenario as an example, if a path from the subway exit to the city square has no obstruction along the route and the directions are consistent, then this segment will form a valid display node group. The system records the first and last nodes of this segment as representative node pairs. The system integrates qualified path segments to obtain a continuously switchable view node group.

[0155] Specifically, such as Figure 2 , 7 As shown, the rendering and display module includes:

[0156] The layer element extraction submodule extracts the urban component layer covered by the path node based on the continuous view switching node group, calls the spatial location index data of the components and the use marking area within the layer, locates the layout and display range of the urban component layer in the view, analyzes the relationship structure between the use area layer and the component layer in the path node, and generates a set of layer display elements.

[0157] Based on the location index of each node, the system retrieves the urban component layer data it covers. The component layer contains 3D elements such as building facades, street facilities, and green areas, and includes spatial range information of the area with usage labels. The system traverses the visible space of each node, extracts the component layers involved and their projection areas in the overall view, and retrieves the spatial index data of each component in the layer. It analyzes the relationship between the component's position in the model scene and the coverage of the usage area to determine whether it belongs to the path segment corresponding to the node. In a city commercial area, the component layers corresponding to the path nodes include shopping mall facades, glass canopies, and signs. The system determines whether the layer is in an area marked "commercial use" based on its spatial position and matches the degree of overlap between the two. The system summarizes the relationship between the associated usage area and the component layers of the path nodes to generate a set of layer display elements.

[0158] The layer order construction submodule, based on the set of elements displayed by the layers, calls the node sequence information of the path advancement, numbers and collects the order of appearance of the layers in the path advancement process, and generates a layer sorting structure index.

[0159] The system performs layer order construction processing during the path advancement phase. It reads the advancement sequence number of each path node and marks the stage number of the path from the start to the end. For example, the numbering sequence is "001", "002" up to "n". The system will match the component layers appearing in the node with their corresponding numbers and assign them to the first path node number. It will also record the temporal relationship between the layer and the node. If a certain office building facade layer first appears in the visible area at path node "003", then the sorting number of that layer will be assigned to "003". For layers that appear consecutively in multiple nodes, the system uses the earliest appearing node as its sorting number reference to ensure that the layer appearance order is consistent with the path logic. After this process is completed, the system will construct a set of data items for each component layer and its corresponding temporal number to form a layer sorting structure index.

[0160] The overlay relationship determination submodule calls the layer sorting structure index, extracts the construction level number of the corresponding landmark of the layer, marks the front layer and the bottom layer of the structure level, performs priority rendering processing, and generates a visual overlay display order set.

[0161] The system extracts the structural hierarchy information of each landmark or component belonging to each layer. Based on the original spatial data of the landmark or component, the system defines its layer number. The main facade component is defined as a first-level structure, and secondary auxiliary components such as signboards and sunshades are defined as second- or third-level structures. The system traverses the layer items in the layer sorting structure and divides them into front and bottom layers according to their layer numbers, assigning them labels to determine the display priority during the rendering process. In the urban main road scene, if the advertising tower layer is a first-level structure and the background building layer is a third-level structure, the system marks the advertising tower layer as the front layer and the background layer as the overlay bottom layer. After determining the layer hierarchy, the system prioritizes the front layer and overlays the layers in order of hierarchy to ensure that the occlusion and display relationships between layers are not confused during visual display. After summarizing the layer priority rendering relationships, a visual overlay display order set is formed.

[0162] The view rendering submodule calls the visual overlay display order set, which groups the component layer, purpose layer and landmark structure layer in the path node according to the display order, performs layer combination mapping operation and performs path dynamic projection on the combined layer structure to obtain the city model visualization rendering view set.

[0163] The system uniformly groups the component layers, purpose layers, and landmark layers involved in the path nodes. Multiple layers within the same node are categorized and organized according to a predetermined display order, forming structures such as a top display layer, a middle functional layer, and a bottom background layer. Layer combination mapping is then performed to merge the layers into a unified visual structure. During the combination process, different purpose categories of layers undergo visual processing such as color and transparency adjustments to ensure clear distinction between layer contents, facilitating user identification and operation. The system performs dynamic path projection on the combined layer structure based on the path node progression order, displaying each combined layer structure as a continuously switching scene view according to the path sequence. In scene browsing, the system smoothly transitions from street nodes to plaza nodes, and then moves from the plaza to the main building entrance node. Layer content is loaded and overlaid in a predetermined order at each step, including the combined layer display content and progression logic corresponding to the path nodes. This can be used for various view interaction needs such as navigation, display, and simulation, outputting a city model visualization rendering view set.

[0164] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A digital urban design city model visualization system, characterized in that, The system includes: The usage identification module acquires standard usage units in urban space, records the occurrence information of each usage in the unit, transforms the records into a spatial distribution structure, identifies the orientation relationship of unit anchor points, and rebinds them with usage labels to obtain the spatial usage anchor point layer structure. Based on the spatial use anchor point layer structure, the component combination module extracts three-dimensional building components from the city model, classifies the functional semantic tags of the three-dimensional building components, and combines and arranges the spatial layout of the components to obtain a semantic component assembly display unit. The path guidance module assembles display units based on the semantic components, extracts the associated landmark node information, detects the guidance relationship between adjacent landmarks according to the order of nodes in the path advancement, and filters the display priority of the node sequence in the continuous guidance direction to obtain the path stage display sequence. Based on the path-stage display sequence, the view scheduling module analyzes the view relationships of key nodes in the path, identifies the occlusion structure and orientation continuity of adjacent landmarks in the path, and performs directional scheduling of display views for nodes with occlusion and orientation deviation to obtain a continuous view switching node group. The path guidance module includes: The landmark node extraction submodule extracts landmark components from the associated path advancement nodes based on the semantic component assembly and display unit, synchronously merges the position index and functional semantics of the landmarks in the component group, evaluates the bidirectional matching degree of the path node and landmark correspondence, and obtains the path landmark matching index group. The visual feature collection submodule identifies the usage category information of the path landmarks, constructs hierarchical attributes and identifies appearance features based on the path landmark matching index group, classifies and integrates the visual feature labels of the landmarks, and performs structured sorting processing on the usage category and hierarchical data to obtain the landmark feature structure sequence. The guidance relationship detection submodule calls the landmark feature structure sequence, extracts the connection direction vector between adjacent nodes according to the node numbering order in the path advancement, detects the orientation continuity between continuous nodes and the change status of landmark label type, and marks the landmark node sequence with the same direction and unchanged label as a continuous guidance path segment to obtain the landmark connection sequence identifier. The priority filtering and sorting submodule calls the landmark connection sequence identifier, extracts the display order number of the path segment and the landmark structural feature level, compares and filters the display priority of path segments with structural hierarchy advantages and connection stability, and performs sorting update according to visual extension relationship to obtain the path stage display sequence. The view scheduling module includes: The perspective node analysis submodule extracts key nodes in the path advancement based on the path stage display sequence, calls the spatial coordinate data and path connection relationship corresponding to the key nodes, divides the monitoring angle between nodes into intervals, constructs the perspective extension direction map between nodes, and generates path perspective association structure group. The occlusion relationship recognition submodule extracts the occlusion distribution of components between nodes based on the path view associated structure group, calls the facade outline and spatial height information of the three-dimensional components, performs position intersection determination on component areas with overlapping boundaries, and marks the occlusion degree level of the corresponding path nodes to obtain the node occlusion status determination result. The viewpoint direction adjustment submodule calls the node occlusion status determination result, filters the set of nodes marked as having deviation in occlusion level, compares the angle between the real-time viewpoint direction and the path forward direction, and if there is a deviation in direction, performs repositioning of the node monitoring direction, updates the node viewpoint pointing attribute, and obtains the display node viewpoint adjustment group.

2. The digital urban design city model visualization system according to claim 1, characterized in that, The spatial use anchor point layer structure includes the anchor point offset trajectory within the use boundary, the anchor point use label binding relationship, and the anchor point spatial hierarchy distribution. The semantic component assembly display unit includes component combination layout blocks, component semantic label mapping relationship, and component linkage sequence node chain. The path stage display sequence includes a display path node index set, a path advancement direction sequence, and a landmark guidance level marker group. The continuous view switching node group includes continuous viewable node pairs, view direction adjustment marker group, and occlusion relationship determination mark set.

3. The digital urban design city model visualization system according to claim 1, characterized in that, The purpose calibration module includes: The submodule for constructing use units acquires standard use units in urban space, collects the types of use tags within standard use units, categorizes and records the occurrence of the same use in multiple units, performs use division and aggregation operations on units, and generates use distribution classification information. Based on the application distribution classification information, the boundary contour recognition submodule extracts the spatial boundary region for each application, calls the graphic contour data of the closed structure in the boundary region, compares the coordinate set of the contour node positions in the closed contour, identifies the boundary group with continuous closed features, and generates a set of closed contours for application boundaries. The anchor point direction determination submodule extracts the marked anchor point positions within the application boundary based on the closed contour set of the application boundary, calls the spatial direction vector between the anchor point and the center point of the boundary, performs an angle range division operation on the distribution trend of the spatial direction vector, and generates a set of anchor points with consistent direction. The purpose binding adjustment submodule calls the set of anchor points with consistent direction, performs spatial position correction towards the center on the position structure of the anchor points within the boundary, and re-matches the purpose tag category to the corrected anchor points to obtain the spatial purpose anchor point layer structure.

4. The digital urban design city model visualization system according to claim 3, characterized in that, The formula for rematching the usage label category to the corrected anchor points is as follows: ； in, Representing the Anchor point usage tag matching deviation value for usage category tag. Represents the total number of anchor points. Representing the The first under the class tag Corrected spatial displacement distance of each anchor point Representing the The first under the class tag Spatial association weight coefficient between each anchor point and the center of the usage category. and Representing the first The first under the class tag The coordinates of each anchor point in the horizontal and vertical directions. Representing the Reference value for the center position of the class / purpose category in two-dimensional space. Representing the The class label is expected to match a stable constant.

5. The digital urban design city model visualization system according to claim 3, characterized in that, The component assembly module includes: The component extraction and identification submodule extracts urban 3D model components associated with the spatial use anchor point layer structure based on the spatial use anchor point area, compares the spatial location data of the urban 3D model components in the model with the component identification code, identifies the usage area of ​​the urban 3D model components in the urban model, and generates component usage association information. The tag semantic classification submodule calls the functional semantic tags of the urban 3D model components according to the component usage association information, divides and organizes the tag information according to the component type, performs the main tag extraction operation on components with multiple overlapping tags, and generates a functional tag mapping set. The component process filtering submodule calls the function tag mapping set, identifies the design process call order between function tags, sorts the components with continuous call relationships by number, and cross-validates with the purpose attribution data between components. It then filters the component combination nodes with consistent function tags and adjacent process order to obtain continuous grouping records of component processes. The combined layout submodule calls the component process to continuously group and record, detects the spatial layout boundary of the components within the component group, determines the positional relationship between the boundaries, adjusts the position of components with spatial overlap and re-records the layout status, and integrates the coordinate information of the components in the layout with the functional semantics to obtain the semantic component assembly display unit.

6. The digital urban design city model visualization system according to claim 1, characterized in that, The display sequence number and landmark structure feature level of the extracted path segments are determined using the following formula: ； in, R represents the priority value for displaying path segments. a The structural feature level score represents the a-th landmark. The index representing the connection stability of the b-th path segment is... This represents the local position coefficient of the a-th landmark under the k-th visual extension direction. This represents the proportion of the mapped length of the b-th path segment under the k-th visual extension direction. This represents the average display weight of the combination of the a-th landmark and the b-th path segment. represents the standard deviation of the display weights of the combination of the a-th landmark and the b-th path segment in the sample statistics, and N represents the total number of visual extension directions.

7. The digital urban design city model visualization system according to claim 1, characterized in that, The system also includes a rendering and display module: The rendering and display module switches node groups according to the continuous viewpoint, extracts component layers and usage marking areas in the city model, performs layer sorting operations in combination with the path advancement sequence, constructs a visual overlay order according to the landmark structure hierarchy, performs sequential rendering of component layers, and performs projection processing on the usage layer, landmark structure and combined component layer to obtain a set of city model visualization rendering views. The city model visualization rendering view set includes a layer rendering sort table, a combined layer overlay index, and projection results of the usage and component layers.

8. The digital urban design city model visualization system according to claim 7, characterized in that, The rendering and display module includes: The layer element extraction submodule extracts the urban component layer covered by the path node based on the continuous view switching node group, calls the spatial location index data of the components and the use marking area in the layer, locates the layout position and display range of the urban component layer in the view, analyzes the relationship structure between the use area layer and the component layer in the path node, and generates a set of layer display elements. The layer order construction submodule, based on the set of elements displayed by the layers, calls the node sequence information of the path advancement, numbers and collects the order of appearance of the layers in the path advancement process, and generates a layer sorting structure index. The view rendering submodule calls the visual overlay display order set, groups the component layer, purpose layer and landmark structure layer in the path node in a unified manner according to the display order, performs layer combination mapping operation and performs path dynamic projection on the combined layer structure to obtain the city model visualization rendering view set.

Images