CN116842122A - Geographic information system for digital twin city platform - Google Patents
Geographic information system for digital twin city platform Download PDFInfo
- Publication number
- CN116842122A CN116842122A CN202311033760.8A CN202311033760A CN116842122A CN 116842122 A CN116842122 A CN 116842122A CN 202311033760 A CN202311033760 A CN 202311033760A CN 116842122 A CN116842122 A CN 116842122A
- Authority
- CN
- China
- Prior art keywords
- coordinates
- point
- geographic information
- curve
- component
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000009877 rendering Methods 0.000 claims abstract description 36
- 238000006243 chemical reaction Methods 0.000 claims description 34
- 238000012545 processing Methods 0.000 claims description 15
- 238000009499 grossing Methods 0.000 claims description 12
- 238000005070 sampling Methods 0.000 claims description 10
- 238000000605 extraction Methods 0.000 claims description 3
- 239000002689 soil Substances 0.000 claims description 2
- 230000007547 defect Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 21
- 230000008569 process Effects 0.000 description 13
- 238000007726 management method Methods 0.000 description 6
- 238000007654 immersion Methods 0.000 description 5
- 230000000007 visual effect Effects 0.000 description 5
- 238000004364 calculation method Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 230000004044 response Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910052792 caesium Inorganic materials 0.000 description 2
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 241000791900 Selene vomer Species 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000013499 data model Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012800 visualization Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F16/00—Information retrieval; Database structures therefor; File system structures therefor
- G06F16/20—Information retrieval; Database structures therefor; File system structures therefor of structured data, e.g. relational data
- G06F16/29—Geographical information databases
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T15/00—3D [Three Dimensional] image rendering
- G06T15/10—Geometric effects
- G06T15/20—Perspective computation
- G06T15/205—Image-based rendering
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T17/00—Three dimensional [3D] modelling, e.g. data description of 3D objects
- G06T17/05—Geographic models
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Geometry (AREA)
- Software Systems (AREA)
- Remote Sensing (AREA)
- Databases & Information Systems (AREA)
- Computer Graphics (AREA)
- General Engineering & Computer Science (AREA)
- Data Mining & Analysis (AREA)
- Computing Systems (AREA)
- Processing Or Creating Images (AREA)
Abstract
The present application provides a geographic information system for a digital twin city, the system comprising: the geographic information module is used for calculating coordinates of the digital twin city based on the geographic coordinates of the real world and rendering the digital twin city; the interface module is connected with the geographic information module and used for providing a calling interface for the front end; and the navigation module is connected with the geographic information module, and is used for selecting a starting point and an ending point based on the coordinates of the twin digital city calculated by the geographic information module and rendering the starting point and the ending point into a flight preview video. According to the scheme of the application, the defects of the traditional digital twin city are improved, geographic information is added to the traditional digital twin city model building, an efficient geographic information model management mode is provided, the flow loading display of a large model is supported, and the performance loss is reduced; and based on the combined advantages of the geographic information module and the digital twin city, the three-dimensional immersive navigation function of the digital city is realized.
Description
Technical Field
The application belongs to the technical field of digital twinning, and particularly relates to a geographic information system for a digital twinning city platform.
Background
With the rapid development of urbanization, city planning and management becomes more and more complex. The digital twin city is an advanced city management tool integrating multiple technologies, and realizes the sharing and visualization of city data by digitizing various aspects of the city, including building, traffic, environment, etc. The digital twin city can help city planners to know the situation of the city more comprehensively, so that planning and management strategies can be formulated better, and the city efficiency and sustainability are improved.
The current digital twin city lacks global geographic information, so that the city is isolated and free of assistance, and the position information of buildings or objects in the city cannot be intuitively displayed, so that the decision and judgment of people are influenced. In addition, the conventional digital twin city can face the problems of large load pressure, clamping and the like when loading a large model, and cannot smoothly run, and the application effect of the digital twin city is also affected. In order to solve the problems, the application develops a geographic information module special for a digital twin city based on a processing geographic information engine. The geographic information module provides an accurate geographic information model for the digital twin city, and an efficient management mode of the geographic information model is realized, so that smooth display of a large model is realized, the special functions of the geographic information module of the digital twin platform are added, and three-dimensional immersive navigation of the digital city is realized. The geographic information module provides more comprehensive and accurate data support for planning and management of the digital twin city, and improves the effect and user experience of digital twin city application.
The foregoing description is provided for general background information and does not necessarily constitute prior art.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present application provides a geographic information system for digital twin cities, which provides accurate geographic information for digital twin cities, and builds a more perfect and effective digital twin city platform based on the geographic information module, thereby providing key technical support for the functions of using geographic information data in digital cities.
The application provides a geographic information system for a digital twin city, the system comprising: the geographic information module is used for calculating coordinates of the digital twin city based on the geographic coordinates of the real world and rendering the digital twin city; the interface module is connected with the geographic information module and used for providing a calling interface for the front end; and the navigation module is connected with the geographic information module, and is used for selecting a starting point and an ending point based on the coordinates of the twin digital city calculated by the geographic information module and rendering the starting point and the ending point into a flight preview video.
According to one embodiment of the present application, the geographic information module includes:
a coordinate conversion unit for converting real world geographical coordinates and fictive engine world coordinates;
and the parting rendering unit is used for carrying out layering rendering on the digital twin city.
According to an embodiment of the present application, the coordinate conversion unit includes:
a geocentric geodetic coordinate conversion component for converting real world geographic coordinates to geodetic coordinates;
a northeast-day coordinate conversion component for converting the geocentric earth coordinates into northeast-day coordinates;
and converting the northeast coordinates into the illusive engine coordinates conversion component.
According to one embodiment of the present application, a hierarchical rendering unit includes:
a render-acknowledge component for determining whether to render the node;
a selection component for selecting a rendering model.
According to one embodiment of the application, the navigation module comprises:
a data processing unit that determines flight path data based on the acquired navigation data;
a drawing unit for determining a flight preview curve and rendering based on the flight path data;
and generating a flight unit of the flight preview video based on the flight preview curve and the rendering result.
According to one embodiment of the application, the data processing unit comprises:
a navigation data acquisition component for acquiring a starting point and an ending point of navigation based on a map software interface;
the coordinate conversion and key point extraction component is used for converting the coordinates of the map software into the coordinates of the illusion engine and extracting key point information of the navigation path;
and the curve smoothing processing component is used for smoothing the navigation path key point information.
According to one embodiment of the present application, the key point information includes: a start point, an end point, and at least one turning point.
According to an embodiment of the present application, the drawing unit includes:
a curve drawing component for generating a flight preview curve based on the flight path data;
a corner adding component for adding an automatic corner to the inflection point of the flight preview curve;
an identification adding component for adding a steering angle identification to the flight preview curve;
a start point and end point identification component for adding start point and end point identifications to the flight preview curve;
an important landmark representation adding component for representing an important landmark.
According to one embodiment of the application, the flying unit comprises:
a route point reconstruction component for smoothing the flight preview curve;
a surrounding point sampling component for determining a new point of the flight preview curve based on the coordinates around the point set of the flight preview curve;
and generating a mirror assembly of the flight preview video based on the information of the flight preview curve and the rock-soil of the flight preview curve.
According to one embodiment of the application, the mirror assembly, when performing a mirror, comprises: the operation mirror is operated in a overlook view, and is operated to the starting point and the flying operation mirror.
As described above, the geographic information system for digital twin cities of the present application has the following advantageous effects:
1. the shortcomings of the traditional digital twin cities are improved. The traditional digital twin city lacks geographic information modules, so that building models and the like lack geographic information, further the data quality, the credibility of simulation results and the accuracy of city planning management decisions are affected, and the functions of the digital city cannot be fully exerted.
2. When loading a large model, the traditional digital twin city has the problem of performance loss, so that the system is not smooth in operation and even is blocked. The geographic information module in the application adopts an LOD (level detail) mode, and only renders the model in a proper range or with proper precision according to comprehensive judgment of the distance between the model and the camera, the FOV angle of the camera and the like, so that the system performance can be obviously improved.
3. The geographic information module develops interfaces for all functions, is efficient and easy to use, can conveniently realize scene initialization at the front end, sets view angles, base diagrams, terrains, models and the like, and provides practical functions of focusing view angles to the models, picking up click positions, converting coordinates and the like.
4. Based on the geographic information module, the system also realizes the three-dimensional immersion navigation function of the digital city. Compared with the traditional two-dimensional plane navigation, the three-dimensional immersion navigation is more visual and easy to use. The user can go deep into the two-dimensional map scene and watch the real three-dimensional space scene information, and the immersive route navigation experience is obtained. Meanwhile, the system also provides digital Li Shengchao realistic rendering cloud service, so that a user can experience multidimensional meta-universe navigation, and indoor spaces which cannot be covered by traditional navigation, such as scenes of markets, underground garages and the like, are covered. .
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a geographic information system for a digital twin city according to an embodiment of the present application.
Fig. 2 is a schematic diagram of data access of a geographic information system for a digital twin city according to an embodiment of the present application.
FIG. 3 is a flow chart illustrating a data processing preparation stage according to an embodiment of the present application.
Fig. 4 is a flow chart of a navigation phase according to an embodiment of the application.
Detailed Description
Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the application. Rather, they are merely examples of apparatus and methods consistent with aspects of the application as detailed in the accompanying claims.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the element defined by the phrase "comprising one … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element, and furthermore, elements having the same name in different embodiments of the application may have the same meaning or may have different meanings, the particular meaning of which is to be determined by its interpretation in this particular embodiment or by further combining the context of this particular embodiment.
It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, these information should not be limited by these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope herein. The word "if" as used herein may be interpreted as "at … …" or "at … …" or "responsive to a determination", depending on the context. Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" specify the presence of stated features, steps, operations, elements, components, items, categories, and/or groups, but do not preclude the presence, presence or addition of one or more other features, steps, operations, elements, components, items, categories, and/or groups. The terms "or", "and/or", "including at least one of", and the like, as used herein, may be construed as inclusive, or mean any one or any combination. For example, "including at least one of: A. b, C "means" any one of the following: a, A is as follows; b, a step of preparing a composite material; c, performing operation; a and B; a and C; b and C; a and B and C ", again as examples," A, B or C "or" A, B and/or C "means" any of the following: a, A is as follows; b, a step of preparing a composite material; c, performing operation; a and B; a and C; b and C; a and B and C). An exception to this definition will occur only when a combination of elements, functions, steps or operations are in some way inherently mutually exclusive.
It should be understood that, although the steps in the flowcharts in the embodiments of the present application are shown in order as indicated by the arrows, these steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited in order and may be performed in other orders, unless explicitly stated herein. Moreover, at least some of the steps in the figures may include multiple sub-steps or stages that are not necessarily performed at the same time, but may be performed at different times, the order of their execution not necessarily occurring in sequence, but may be performed alternately or alternately with other steps or at least a portion of the other steps or stages.
The words "if", as used herein, may be interpreted as "at … …" or "at … …" or "in response to a determination" or "in response to a detection", depending on the context. Similarly, the phrase "if determined" or "if detected (stated condition or event)" may be interpreted as "when determined" or "in response to determination" or "when detected (stated condition or event)" or "in response to detection (stated condition or event), depending on the context.
It should be noted that, in this document, step numbers such as S1 and S2 are adopted, and the purpose of the present application is to more clearly and briefly describe the corresponding content, and not to constitute a substantial limitation on the sequence, and those skilled in the art may execute S4 first and then execute S3 when implementing the present application, which is within the scope of protection of the present application.
It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
In the following description, suffixes such as "module", "part" or "unit" for representing elements are used only for facilitating the description of the present application, and have no specific meaning per se. Thus, "module," "component," or "unit" may be used in combination.
Digital twin refers to a technology for copying and simulating equipment, systems or processes in the physical world in a digital mode, fully utilizes data such as a physical model, sensor update, operation history and the like, integrates simulation processes of multiple disciplines, multiple physical quantities, multiple scales and multiple probabilities, and completes mapping in a virtual space so as to reflect the whole life cycle process of corresponding entity equipment. The digital twin technique can create a real-time, dynamic digital model reflecting the state, location, properties, etc. of its physical counterparts, and can be used to optimize the performance of the device, predict the failure of the device, and provide deeper data holes.
The geographic information model is an abstract data model that is used to represent geospatial data in a Geographic Information System (GIS). Such a model can help us understand and interpret the geographic phenomena of the real world and convert them into data that can be understood and processed by a computer.
Geographic information models are generally divided into two major categories: vector models and grid models.
1. Vector model: the vector model uses points, lines and faces to represent geographic objects. For example, a point may represent a location (e.g., a city location), a line may represent a path (e.g., a highway or river), and a face may represent an area (e.g., a lake or forest). The vector model is particularly suitable for representing clear, continuous geographic objects such as roads, buildings, and the like.
2. Grid model: the grid model divides the geospatial space into a series of regular grids, each grid cell having a value representing a property of the cell. For example, a grid model may represent terrain elevation, where the value of each cell represents the altitude of the place. The grid model is particularly suited to represent continuously varying geographic phenomena such as temperature, humidity, altitude, etc.
Both models have their advantages and disadvantages, and the particular model used depends on the particular application requirements and data type.
The layers are made up of a collection of map elements that have a common function or theme. Such as roads, rivers, POI points, etc.
Cesium is an open source JavaScript library for creating world-level 3D earth and maps. It provides a method of presenting high quality global and local level 3D maps on the Web. Cesium supports various geographic information data formats and services including WMS, TMS, CZML, billboards, polylines, and 3D Models, among others.
Referring to fig. 1 and 2, the geographic information system for digital twin cities provided by the present application includes: the geographic information module is used for calculating coordinates of the digital twin city based on the geographic coordinates of the real world and rendering the digital twin city; the interface module is in communication connection with the geographic information module and is used for providing a calling interface for the front end; and the navigation module is in communication connection with the interface module and is used for rendering the flight preview video from the starting point to the end point.
In the embodiment of the application, in order to introduce true geographic information data into the digital twin city, the geographic information module is the most important support, and is mainly used in the digital twin city, on one hand, how to calculate the real world geographic coordinate information to the correct position in the digital twin city, namely calculate the correct coordinates; on the other hand, how to conduct layered rendering on the digital twin cities is solved, so that the consumption of the performance of a hardware system is reduced, and the corresponding power consumption is reduced.
In the embodiment of the application, in order to facilitate each function to call the geographic information system for the digital twin city, the corresponding call interface, such as an API interface, is provided by connecting the interface module with the geographic information module, so that personnel can conveniently call the data information of the geographic information module through the API interface by the front end. In the embodiment of the application, in order to facilitate different requirements of different users, when a calling interface is set for a geographic information module:
the initialized scene can be customized according to the user's requirements for the initialized scene, including an initial base map, a terrain and geographic information model, and an initial perspective position.
According to the requirements of users, multiple layers of base graphs can be added for superposition, TMS and WMS base graph services are supported at the same time, the base graph display sequence can be adjusted, and the coverage patterns can be adjusted.
According to the requirement of a user on whether to display the hidden geographic information model, whether the geographic information model is rendered and loaded can be set in the digital twin city system.
According to the geographic information model ID provided by the user, a corresponding geographic information model can be searched, the position of a bounding box is determined, a camera is aligned to the position of the bounding box, the looking position of the camera is the center point of the bounding box, the rotation matrix roll of the camera is 0, pitch and yaw are determined according to pitch and yaw of the original camera, and the camera arm length is correspondingly set according to the size of the bounding box, so that the whole geographic information model can be observed in a visual angle, and the visual angle switching is smooth.
According to the coordinates provided by the user and the names of the current coordinate system and the coordinate system expected to be converted, the provided coordinates can be converted into the corresponding coordinates under the coordinate system, and three coordinate systems are provided, namely, a coordinate system of a Unreal engine, an ECEF (Earth-Centered, earth-Fixed) coordinate system and a coordinate-Earth coordinate system for determining a point according to longitude, latitude and altitude, and the user can conveniently and quickly convert the three coordinate systems through an interface.
According to the position clicked by the user mouse, the user can obtain the coordinate of the clicked position, and the returned coordinate can select one of Unreal, ECEF and the geodetic coordinate system.
According to the position clicked by the user mouse, if feature data are written in the geographic information model, the user can obtain the feature data in the geographic information model, for example, the height, the name and the floor number of a building are written in the building information model, and then the user can take the information by clicking the building, so that visual display can be conveniently carried out later.
According to the requirement of the user on the precision of the geographic information model and the ID of the corresponding geographic information model, MSEE (Minimum space error estimation) of the geographic information model can be set, under the same distance, the smaller the MSE value is, the finer the loaded model is, meanwhile, the higher the load is, and the user can set according to the load and the fineness balance.
In addition, according to the convenience requirement of the user, the system also has the api functions of obtaining all geographic information model data, deleting all geographic information models, loading a geographic information model array, modifying the geographic information model, modifying the base map, modifying the terrain and the like, and is convenient for the user to use.
In the embodiment of the application, the navigation module performs navigation between the selected starting point and the selected terminal point in a three-dimensional immersion navigation mode on the basis of the data provided by the geographic information module, and can render a flight preview video from the starting point to the terminal point for providing a visual effect of overlooking to a user.
In one embodiment of the present application, the geographic information module includes: a coordinate conversion unit for converting real world geographical coordinates and fictive engine world coordinates; and the parting rendering unit is used for carrying out layering rendering on the digital twin city.
According to an embodiment of the present application, the coordinate conversion unit includes: a geocentric geodetic coordinate conversion component for converting real world geographic coordinates to geodetic coordinates; a northeast-day coordinate conversion component for converting the geocentric earth coordinates into northeast-day coordinates; and converting the northeast coordinates into the illusive engine coordinates conversion component.
In the embodiment of the present application, the Earth Centered Earth Fixed coordinate (ECEF, earth-Centered, earth-Fixed) is a cartesian coordinate system with its origin at the center of the Earth, the X axis passing through the primary meridian on the equator, the Y axis passing through a point with 90 degrees longitude, and the Z axis passing through the north pole. This conversion process uses the parameters of WGS 84. First, when converting geographic coordinates (longitude, latitude, altitude) into geographic coordinates (ECEF, earth-Centered, earth-Fixed) by a geographic coordinate conversion component in a coordinate conversion unit, processing is performed according to the following conversion formula:
X＝(N+height)×cos(latitude)×cos(longitude)
Y＝(N+height)×cos(latitude)×sin(longitude)
Z＝((N×(1-e 2 ))+height)×sin(latitude)
where N is the earth radius, e is the earth's eccentricity, height is altitude, latitude is latitude, and longitude is longitude.
After calculation by the above formula, the real world geographic coordinates are converted into geocentric fixed coordinates. After the geocentric earth fixed coordinates are obtained by calculation according to the formula, further, the geocentric earth fixed coordinates (ECEF) are converted into northeast (ENU) coordinates through an northeast (ENU) coordinate conversion component, wherein the northeast (ENU) is a local Cartesian coordinate system, the origin of the northeast (ENU) coordinate system is positioned at an observer, the X axis points to the East, the Y axis points to the North, and the Z axis points to the sky. This conversion process requires the use of geographical coordinates of the observer.
After the northeast day (ENU) coordinate is obtained through conversion, further, the northeast day (ENU) coordinate is converted into the illusion engine coordinate through the illusion engine coordinate conversion component, and the conversion process is mainly the exchange and inversion of one coordinate axis because the illusion engine coordinate uses a left-hand coordinate system and the Z axis points upwards. The conversion is performed according to the following conversion formula:
UnrealX＝ENU_East
UnrealY＝ENU_Up
UnrealZ＝-ENU_North
through the calculation conversion of the three steps, the phantom engine coordinate is finally obtained through the real world geographic coordinate, and it is noted that because the earth is an ellipsoid, in the large-scale and high-precision geographic information processing, the simple coordinate conversion may generate errors.
According to one embodiment of the present application, after the conversion of the real world geographic coordinates into the fictive engine coordinates is completed by the coordinate conversion unit, further hierarchical rendering of the large-scale geographic data is achieved by the hierarchical rendering unit using the data structure of the 3D Tiles. Wherein the data structure of 3D Tiles is a tree-like tile set, where each node represents a model or set of models and has its own scope. In the rendering process, the hierarchical rendering unit decides whether to render the model represented by the node according to the range of the node and the distance of the field of view through a rendering determining component contained therein, and selects the version of the rendering model through a selecting component, thereby realizing hierarchical level detail (LOD). Among the key parameters affecting hierarchical detail (LOD) selection are three parameters of 'maximumscreen spacererror', 'binding volume' and 'geometry error'.
In this embodiment, the buffering volume describes the location and size of the Tileset in the world, and is used to decide whether or not the Tileset needs to be rendered, and which version of the Tileset to render. In hierarchical rendering, 'binding volume' is a very critical parameter. It describes the position and size of a Tileset (i.e. a set of 3D Tiles) in space. Each node (or each Tile) has its own 'binding volume', which describes the location and size of the model represented by the node in the world.
In this embodiment, the geometry error is a numerical value for expressing the geometric accuracy of one tile. In general, a smaller value of a tile 'geometry error' indicates a higher geometry, and a larger value indicates a lower geometry. In the data structure of 3D Tiles, the Tiles are typically organized according to a hierarchy. In the rendering process, the system starts from the root node and decides whether to continue traversing its child nodes according to the 'geometry error' of each tile. Generally, if a tile 'geometry error' is small enough (i.e., its geometry is high enough), then the system does not need to traverse its children again, thereby saving computing resources.
In this embodiment, maximumscreen space error is a numerical value for controlling the level of detail in hierarchical rendering. Which defines a threshold that determines to what extent the level of detail of the model should be when rendering the 3D model or terrain. The smaller the value of this parameter, the finer the rendered model, as more levels of detail (higher resolution tiles) will be loaded and rendered. Conversely, if this value is set larger, the rendered model will be coarser, as lower resolution tiles will be loaded.
According to the embodiment of the application, the navigation module further realizes a three-dimensional immersion navigation function on the basis of geographic information access, and can render a flight preview video from a starting point to an end point by selecting the starting point and the end point for navigation.
In the embodiment of the application, when the navigation module renders the flight preview video, firstly, the data processing unit determines the flight path data based on the acquired navigation data, and in a preferred implementation mode, the navigation data component is acquired, the API function of the Goldmap is used, the starting point and the end point of navigation are used as input, and the navigation data in a JSON format is acquired. The navigation data includes a navigation route composed of a start point, a position coordinate of an end point, and a plurality of paths (paths), each path including a plurality of points. Each path represents a relatively straight curve, and the angles between different paths may differ significantly. The coordinate conversion and key point extraction component converts the coordinates of the map software into the coordinates of the illusion engine, and extracts key point information of the navigation path, and the coordinate conversion unit converts the longitude and latitude coordinates provided by the Goldmap into a coordinate system suitable for the illusion engine for compatibility with the subsequent processing flow. And processing the acquired coordinate data. First, key point information of a navigation path including a start point, an end point, a turning point, and the like is extracted. These key points play a vital role in the subsequent processing. And smoothing the integral curve point data by a curve smoothing component. In a preferred embodiment, a fixed length value is used as a sampling interval, the curve is uniformly sampled, and the sampling points are used as three-dimensional curve points for subsequent processing. Thus, the curve can be smoother and more continuous, and the fluency in the flying process is ensured.
Next, the drawing unit determines a flight preview curve based on the flight path data and performs rendering. Specifically, a flight preview curve is generated by a curve drawing component based on flight path data, and in the embodiment, the curve drawing component generates a smooth curve in a three-dimensional coordinate system according to an input point set through interpolation calculation and curve fitting technology. The shape of the curve can be adjusted according to the position of the input point and the curve characteristic so as to meet different application requirements. The corner adding component adds an automatic corner to the inflection point of the flight preview curve, and in the embodiment, the corner adding component can automatically add the corner at the inflection point of the curve according to the input path information and the corner requirement, and the smooth connection of the path is maintained. The shape and the angle of the corner can be adjusted according to specific requirements so as to adapt to different navigation scenes. The steering angle identification is added to the flight preview curve by an identification adding component to provide navigation indications, for example, the identified location includes a start point for each path provided by the Goldmap, the start point representing a large degree of change in path direction. For longer paths approaching straight lines, the markers are placed at a prescribed separation distance. The steering angle of the mark is obtained by finding the curve smoothing point closest to the mark point to be placed and calculating the angle of the straight line between the point and the front and rear points. To achieve good performance, the identification of dynamically variable arrows based on the Unreal blueprint package can be flexibly demonstrated between-110 degrees and 110 degrees. The start point and end point identification component is used for adding the start point and end point identification to the flight preview curve, for example, name information of the start point and the end point is displayed on the identification, and a user can freely customize the icon and the color of the identification according to personal preference so as to improve personalized experience of navigation. The method and the system have the advantages that the important landmarks are represented through the important landmark identification adding component, for example, important landmarks are identified in the flying or navigation process, such as public facilities (e.g. toilets, subway stations and the like) in order to provide more practical information. By identifying these important landmarks in a three-dimensional scene, a user can more conveniently obtain practical spatial location information when navigating using three-dimensional immersion.
Referring to fig. 3 and 4, a flight preview video is generated by the flight unit based on the flight preview curve and the rendering result. In the embodiment of the application. And smoothing the flight preview curve through a route point reconstruction component. In the embodiment of the application, the line points acquired by the Gooder API are processed by adopting a line point reconstruction method. First, an initial curve is drawn from the line points obtained by the Goodyear API, which curve has been smoothed to some degree. And then uniformly sampling by the same line segment length, obtaining sampling points on the initial curve, and drawing the curve again by taking the sampling points as new input so as to realize secondary smoothing. And obtaining a uniformly sampled and smoother flight curve through reconstruction and secondary smoothing of the line points. A new point of the flight preview curve is determined by a surrounding point sampling component based on coordinates surrounding a set of points of the flight preview curve. In the embodiment of the application, the flight curve is smoothed more fully by the surrounding point sampling technology. The surrounding point sampling is a new point calculated by considering its own and the coordinate information of the surrounding five points on the basis of each point on the curve. For special processing of edge points, only the surrounding three points are used for computation. By introducing the information of surrounding points, the obtained curve will not generate abrupt corners, thereby ensuring smoothness and smoothness during flight and avoiding abrupt turns or jitters. Generating a flight preview video by a mirror assembly, for example, in an overall mirror design that is designed to reveal the overall area and path extent through a 30 second video while simultaneously showing street view aspects along the way, is as follows:
first, a user initially views the entire area, a top view may be employed. The height of the camera view angle is determined by multiplying the distance between the start point and the end point by a multiple, the field of view (FOV) is increased, and the top view angle (Pitch) is set to 40 degrees. Under the view angle, the user can quickly know the whole condition of navigation, and the navigation direction is consistent with the default view angle of the Goldmap, and the route angle and the trend are basically the same.
Secondly, by the mirror-moving mode of turning to the starting point, after overlooking, the camera view angle is shifted to the starting point position and towards the end point direction. At this time, the FOV is reduced, and the user can view the vicinity of the start point while maintaining a top view angle of 40 degrees.
Again, by flying the mirror, the camera flies along the three-dimensional curve, at this time the look-down angle is raised, the FOV is further reduced, focusing on the street view in flight. When the camera reaches the end point, the overhead view angle is increased to overhead view the end point, and the situation around the end point can be viewed in more detail. Finally: and the camera returns to the global overlook view angle at the beginning again, the design of the whole fortune mirror is completed, and finally the flight preview video is generated.
The above is merely a specific implementation of the present application, and the above scenario is merely an example, and does not limit the application scenario of the technical solution provided by the embodiment of the present application, and the technical solution of the present application may also be applied to other scenarios. Any person skilled in the art can easily think of changes or substitutions within the technical scope of the present disclosure, and the present disclosure is intended to be covered by the present disclosure. Therefore, the technical scheme provided by the embodiment of the application is applicable to similar technical problems.
In the present application, the same or similar term concept, technical solution and/or application scenario description will be generally described in detail only when first appearing and then repeatedly appearing, and for brevity, the description will not be repeated generally, and in understanding the present application technical solution and the like, reference may be made to the previous related detailed description thereof for the same or similar term concept, technical solution and/or application scenario description and the like which are not described in detail later.
Claims (10)
1. A geographic information system for a digital twinned city, the system comprising:
the geographic information module is used for calculating coordinates of the digital twin city based on the geographic coordinates of the real world and rendering the digital twin city;
the interface module is connected with the geographic information module and used for providing a calling interface for the front end;
and the navigation module is connected with the geographic information module, and is used for selecting a starting point and an ending point based on the coordinates of the twin digital city calculated by the geographic information module and rendering the starting point and the ending point into a flight preview video.
2. The system of claim 1, wherein the geographic information module comprises:
a coordinate conversion unit for converting real world geographical coordinates and fictive engine world coordinates;
and the parting rendering unit is used for carrying out layering rendering on the digital twin city.
3. The system according to claim 2, wherein the coordinate conversion unit includes:
a geocentric geodetic coordinate conversion component for converting real world geographic coordinates to geodetic coordinates;
a northeast-day coordinate conversion component for converting the geocentric earth coordinates into northeast-day coordinates;
and converting the northeast coordinates into the illusive engine coordinates conversion component.
4. The system of claim 2, wherein the hierarchical rendering unit comprises:
a render-acknowledge component for determining whether to render the node;
a selection component for selecting a rendering model.
5. The system of claim 1, wherein the navigation module comprises:
a data processing unit that determines flight path data based on the acquired navigation data;
a drawing unit for determining a flight preview curve and rendering based on the flight path data;
and generating a flight unit of the flight preview video based on the flight preview curve and the rendering result.
6. The system of claim 5, wherein the data processing unit comprises:
a navigation data acquisition component for acquiring a starting point and an ending point of navigation based on a map software interface;
the coordinate conversion and key point extraction component is used for converting the coordinates of the map software into the coordinates of the illusion engine and extracting key point information of the navigation path;
and the curve smoothing processing component is used for smoothing the navigation path key point information.
7. The system of claim 6, wherein the keypoint information comprises: a start point, an end point, and at least one turning point.
8. The system according to claim 5, wherein the drawing unit includes:
a curve drawing component for generating a flight preview curve based on the flight path data;
a corner adding component for adding an automatic corner to the inflection point of the flight preview curve;
an identification adding component for adding a steering angle identification to the flight preview curve;
a start point and end point identification component for adding start point and end point identifications to the flight preview curve;
an important landmark identification adding component for representing an important landmark.
9. The system of claim 5, wherein the flying unit comprises:
a route point reconstruction component for smoothing the flight preview curve;
a surrounding point sampling component for determining a new point of the flight preview curve based on the coordinates around the point set of the flight preview curve;
and generating a mirror assembly of the flight preview video based on the information of the flight preview curve and the rock-soil of the flight preview curve.
10. The system of claim 9, wherein the mirror assembly, when performing a mirror, comprises:
the operation mirror is operated in a overlook view, and is operated to the starting point and the flying operation mirror.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311033760.8A CN116842122A (en) | 2023-08-16 | 2023-08-16 | Geographic information system for digital twin city platform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311033760.8A CN116842122A (en) | 2023-08-16 | 2023-08-16 | Geographic information system for digital twin city platform |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116842122A true CN116842122A (en) | 2023-10-03 |
Family
ID=88169247
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311033760.8A Pending CN116842122A (en) | 2023-08-16 | 2023-08-16 | Geographic information system for digital twin city platform |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116842122A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117786147A (en) * | 2024-02-26 | 2024-03-29 | 北京飞渡科技股份有限公司 | Method and device for displaying data in digital twin model visual field range |
-
2023
- 2023-08-16 CN CN202311033760.8A patent/CN116842122A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117786147A (en) * | 2024-02-26 | 2024-03-29 | 北京飞渡科技股份有限公司 | Method and device for displaying data in digital twin model visual field range |
| CN117786147B (en) * | 2024-02-26 | 2024-05-28 | 北京飞渡科技股份有限公司 | Method and device for displaying data in digital twin model visual field range |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5105643B2 (en) | System for texture rising of electronic display objects | |
| Batty et al. | Visualizing the city: communicating urban design to planners and decision-makers | |
| KR101962394B1 (en) | Prominence-based generation and rendering of map features | |
| US9235906B2 (en) | Scalable processing for associating geometries with map tiles | |
| CN108759840A (en) | A kind of indoor and outdoor integrated three-dimensional navigation path planning method | |
| KR102308960B1 (en) | Methods of specifying global locations including indoor locations and database using the same | |
| Kennedy | Introduction to 3D data: Modeling with ArcGIS 3D analyst and google earth | |
| US11790603B2 (en) | Dynamic building extrusion in electronic maps | |
| CN108337664A (en) | Tourist attraction augmented reality interaction guide system based on geographical location and method | |
| CN116842122A (en) | Geographic information system for digital twin city platform | |
| Khayyal et al. | Creation and spatial analysis of 3D city modeling based on GIS data | |
| KR102553567B1 (en) | Indoor maps using floor plans based on actual measurements and methods for creating them | |
| CN111986320B (en) | Smart city application-oriented DEM and oblique photography model space fitting optimization method | |
| Zhang et al. | Three-dimensional waterway system for ship navigation based on integrated virtual waterway and flow simulation | |
| Sharma et al. | Navigation in AR based on digital replicas | |
| Burkard et al. | Mobile location-based augmented reality framework | |
| Khan et al. | Indoor navigation systems using annotated maps in mobile augmented reality | |
| Lei et al. | System Development of Making an Image Map Based on Google Earth | |
| Adami et al. | 3D digital maps: New development in cartography for cultural heritage | |
| Nguyen et al. | Toward an Intelligent Maps Construction Framework: A Case-study of VKU Campus Map | |
| Sorna et al. | MonuAR: MAR Application for Visualising 3D Monuments | |
| Sun et al. | Research on Key Technologies for Construction of Smart City Visualization System and Scene 3D Model | |
| Hamza et al. | GIS Planning, Web and 3D Web GIS Applications for the Management and Analysis of MV/LV Electrical Networks in the Region of Medjez el Bab (North-West of Tunisia) | |
| CN115760521A (en) | Method for fusing population distribution data and three-dimensional model scene | |
| Hu et al. | Dynamic response of 3-D vehicle-born laser point cloud and 2-D symbol based on the ArcGIS Engine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |