CN-121996850-A - Urban information model two-dimensional and three-dimensional data service dynamic projection method and system based on WebGL

CN121996850ACN 121996850 ACN121996850 ACN 121996850ACN-121996850-A

Abstract

The invention belongs to the technical field of urban information models, and relates to a dynamic projection method and a dynamic projection system for two-dimensional data service of a urban information model based on WebGL. The method comprises the steps of judging the type of the requested service according to the URL address of the data service, acquiring metadata information of the data service to be loaded, judging whether the metadata information contains content of identification coordinate system information, if not, receiving an external statement, transmitting the external statement into a coordinate system, if the data service contains the defined coordinate system information, analyzing the coordinate system information of the data service, and calling corresponding dynamic projection components according to different service types to carry out dynamic projection transformation of the data service. According to the method, the data service is dynamically projected to the earth surface in real time in the browser environment, the problems of data isolation, preprocessing inefficiency and operation and maintenance redundancy existing in the existing scheme are solved, and the technical bottleneck that the existing Web-end three-dimensional scene cannot dynamically process multi-coordinate system data is broken through.

Inventors

FU YIHAN
CHEN QIZHI
CHEN BIAO
WANG QUANLIE
SUN LIANGZHONG

Assignees

奥格科技股份有限公司

Dates

Publication Date: 20260508
Application Date: 20251218

Claims (10)

1. A city information model two-dimensional data service dynamic projection method based on WebGL is characterized by comprising the following steps: s1, judging the type of the requested service according to the URL address of the data service, and acquiring metadata information of the data service to be loaded; S2, judging whether the metadata information contains the content of the identification coordinate system information, if not, receiving an external statement, and transmitting the external statement into a coordinate system; s3, calling corresponding dynamic projection components according to different service types to perform dynamic projection transformation of the data service.
2. The method according to claim 1, wherein the dynamic projection component comprises a static slice dynamic projection component, a dynamic service dynamic projection component, and a three-dimensional data service dynamic projection component, and step S3 comprises: S31, completing front-end dynamic projection transformation of static slicing service through a static slicing dynamic projection assembly; s32, realizing front-end dynamic projection transformation of dynamic element service and dynamic tile service through a dynamic service dynamic projection component; s33, realizing front-end dynamic projection transformation of the three-dimensional slicing service through the three-dimensional data service dynamic projection component.
3. The dynamic projection method according to claim 2, wherein the front-end dynamic projection transformation of the static slicing service in step S31 comprises the steps of: s311, firstly judging a coordinate system of the data service, and determining different service slicing schemes for processing according to different coordinate systems; S312, judging whether a slicing scheme of the slice is a standard scheme or not; S313, processing a non-standard slicing scheme level; S314, constructing a mapping relation between the tile pyramid model and a coordinate system; S315, judging the data format of the static tiles, and drawing and rendering the tile data of different types on the map in different modes.
4. The dynamic projection method according to claim 3, wherein the determination of whether the slicing scheme is the standard scheme in step S312 is as follows: preprocessing input parameters; detection was performed using two conditions, judging that the 0 th slice range was not equal to 180 degrees: a first condition that checks whether the 0 th slice range is not equal to 180 degrees; A second condition, confirming that the hierarchy identification of the 0 th level slice is indeed 0; When the two conditions are met simultaneously, judging that the 0 th level slice of the corresponding slicing scheme is not the real 0 th level but a non-standard level; step S313 includes, for a non-standard slicing scheme hierarchy, processing steps including: Calculating the number of the 0 th level slices in the Y direction, and calculating the total number of the slices of the corresponding level according to the 0 th level resolution of the slices; multiplying the basic resolution by the number of 0 th-level slices in the Y direction to obtain the 0 th-level resolution which is actually used; rectangular boundary points are constructed, for southwest angles, the product of resolution and slice height is subtracted from the Y value of the origin coordinate of the slice, and for northeast angles, the X value is added by 2 times of the product of resolution and slice width, and the Y value maintains the Y coordinate of the origin of the slice.
5. A dynamic projection method according to claim 3, wherein step S314 comprises: dividing the global surface into a grid of tiles of multiple levels, a low level covering the global with a few tiles, a high level containing finer local tiles; The relation between the earth tile coordinate system and longitude and latitude is expressed by adopting a WGS84 geographic coordinate system, wherein the earth tile is marked by a (z, x, y) triplet, z represents a level with a value of 0-N, x represents a column number increasing from left to right, and y represents a row number; According to the pyramid model and the slicing scheme, calculating the row and column numbers of the requested tiles, firstly checking the boundary, checking whether the positions are in the rectangular range of the tile scheme, then calculating the number of tiles, obtaining the total number of tiles in the X direction and the Y direction according to the hierarchy, then calculating the size of the tiles, then carrying out coordinate projection conversion, projecting the geographic coordinates to a Web ink card support coordinate system, then calculating the distance from the Western boundary and the distance from the North boundary, finally calculating the coordinates of the tiles, and processing the boundary to ensure that the coordinates of the tiles do not exceed the range of the number of tiles.
6. A dynamic projection method according to claim 3, wherein in step S315: If the tile is a STK terrain tile, loading a corresponding elevation model in a corresponding range directly according to the row number; if the tile is HEIGHTMAP grid tile topography, pixel value interpolation is firstly converted into triangular grid data, and then corresponding elevation models are loaded in the corresponding range according to row and column numbers.
7. The dynamic projection method according to claim 2, wherein step S32 includes: S321, acquiring a view range and a dynamic service intersection; S322, judging whether the service providing end supports dynamic projective transformation of the service end, if the requested service providing end supports dynamic projective transformation, modifying a dynamic service request sent by the client end, if the requested dynamic slice or data service does not support dynamic projective transformation of the service end, carrying out dynamic projective transformation on the client end, calculating the projective relation between the range of the requested tile and the range in the map, and converting the WGS84 longitude and latitude rectangular range back to the rectangular range of the original coordinate system; S323, requesting data from the server according to the converted coordinate system range and the coordinate reference; S324, judging whether the service type is a dynamic tile or dynamic vector data, if the service type is the dynamic tile, attaching the picture data to the earth surface as textures according to a geographic range, and if the service type is the dynamic vector data, calling GaussKrugerToGeographic to dynamically convert the returned dynamic vector data point by point into coordinate values required by map drawing and drawing the coordinate values on the map.
8. The dynamic projection method according to claim 2, wherein step S33 includes: S331, judging whether a coordinate system of the three-dimensional slice service is a plane projection coordinate system or a geographic coordinate system; s332, if the coordinate system of the three-dimensional slicing service is a geographic coordinate system, completing model construction and rendering and displaying on a map according to rules calculated by child nodes based on the global change matrix of the father node; S333, if the coordinate system of the three-dimensional slice service is a plane projection coordinate system, setting a center point as an origin of a geocentric fixed coordinate system; S334, traversing the child nodes according to the data in the loading range, calling GaussKrugerToGeographic to convert the traversed child node bounding box center point into longitude and latitude coordinates, and converting the longitude and latitude coordinates into an ENU matrix; S335, judging the service type is 3Dtiles, I3S or other, if the service type is I3S, converting the transformation matrix from column priority to row priority; S336, calculating a transformation matrix of the child node based on the origin of the spherical center coordinates of the parent node; s337, creating one node by one node according to the calculated transformation matrix, and completing the construction of a model; S338, modifying the root node transformation matrix according to the transformation matrix relative to the sphere center in the metadata.
9. The dynamic projection method according to claim 1, wherein step S2 passes the external declaration into the WKT coordinate system or WKID coordinate system.
10. A WebGL-based two-dimensional data service dynamic projection system for urban information model, implemented by the dynamic projection method according to any one of claims 1 to 9, characterized in that it comprises: The metadata information acquisition module judges the type of the requested service according to the URL address of the data service and acquires metadata information of the data service to be loaded; The coordinate system information analysis module is used for judging whether the metadata information contains the content of the identification coordinate system information, if not, receiving an external statement and transmitting the external statement into the coordinate system; And the dynamic projection module is used for calling corresponding dynamic projection components according to different service types and carrying out dynamic projection transformation of the data service.

Description

Urban information model two-dimensional and three-dimensional data service dynamic projection method and system based on WebGL Technical Field The invention belongs to the technical field of urban information models (CIM), and particularly relates to a dynamic projection method and a dynamic projection system for two-dimensional data service of a urban information model based on WebGL. Background With the development of urban information model (CIM), live-action three-dimensional china, digital twin cities, urban global digital transformation, novel urban infrastructure construction and other works, more and more equipment and more advanced technology for three-dimensional data acquisition and production, three-dimensional data of cities are explosively increased, and a large amount of white model, oblique photography, artificial fine model, laser point cloud, BIM and other data are generated almost every day, and finally the data are converged into a unified data platform of the cities, such as the urban information model (CIM) platform, so as to form a public digital base of the cities. The data usually exist in a service form in a platform, and how to realize dynamic projection display of the data services of different coordinate systems is a problem to be solved. The traditional plane projection three-dimensional model cannot be loaded and directly attached to the curved surface of the earth, for projection of three-dimensional data, such as I3S data service, two sets of service SLPK files which are required to be independently maintained in an original multi-coordinate system are subjected to projection transformation at a coordinate end, then the service is distributed for use, and a working link is long. The dynamic projection of the data is basically realized at the desktop end, and the data of basically different coordinate systems (such as Gaussian projection, geographic coordinate systems and commercial map coordinate systems) in a Web scene are isolated and cannot be projected onto the earth surface normally. In addition, two sets of services (such as WGS84 edition and local coordinate system edition) are required to be independently maintained in different coordinate systems, and the operation and maintenance cost is increased. Therefore, the existing technology for accessing the multi-coordinate system data into the WEB three-dimensional scene has defects and needs to be improved and developed. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a dynamic projection method and a dynamic projection system for two-dimensional data services of a city information model based on WebGL, which dynamically project the two-dimensional data services of the city on the surface of the earth in real time in a browser environment, solve the problems of data isolation, preprocessing inefficiency and operation and maintenance redundancy in the prior art, and break through the technical bottleneck that the three-dimensional scene of the prior Web end cannot dynamically process the data of a multi-coordinate system. On one hand, the embodiment of the invention provides a city information model two-dimensional three-dimensional data service dynamic projection method based on WebGL, which comprises the following steps: s1, judging the type of the requested service according to the URL address of the data service, and acquiring metadata information of the data service to be loaded; S2, judging whether the metadata information contains the content of the identification coordinate system information, if not, receiving an external statement, and transmitting the external statement into a coordinate system; s3, calling corresponding dynamic projection components according to different service types to perform dynamic projection transformation of the data service. Preferably, the dynamic projection component comprises a static slice dynamic projection component, a dynamic service dynamic projection component and a three-dimensional data service dynamic projection component, and the step S3 comprises the following steps: S31, completing front-end dynamic projection transformation of static slicing service through a static slicing dynamic projection assembly; s32, realizing front-end dynamic projection transformation of dynamic element service and dynamic tile service through a dynamic service dynamic projection component; s33, realizing front-end dynamic projection transformation of the three-dimensional slicing service through the three-dimensional data service dynamic projection component. On the other hand, the embodiment of the invention also provides a city information model two-three-dimensional data service dynamic projection system based on WebGL, which is realized by adopting the dynamic projection method, and the dynamic projection system comprises the following components: The metadata information acquisition module judges the type of the requested service according