CN112686997B - WebGIS-based three-dimensional model data analysis display platform and method - Google Patents
WebGIS-based three-dimensional model data analysis display platform and method Download PDFInfo
- Publication number
- CN112686997B CN112686997B CN202011636521.8A CN202011636521A CN112686997B CN 112686997 B CN112686997 B CN 112686997B CN 202011636521 A CN202011636521 A CN 202011636521A CN 112686997 B CN112686997 B CN 112686997B
- Authority
- CN
- China
- Prior art keywords
- data
- analysis
- dimensional model
- database
- model
- 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.)
- Active
Links
Images
Abstract
The invention discloses a WebGIS (Web geographic information System) -based three-dimensional model data analysis display platform and a WebGIS-based three-dimensional model data analysis display method, wherein the WebGIS-based three-dimensional model data analysis display platform comprises a data management module, a three-dimensional model loading module, a three-dimensional model analysis module and a monomer module; the data management module is used for constructing a tile file database, a PostGIS spatial database and a PostgreSQL database and managing basic terrain data, oblique photography model data and vector element data according to different organization forms of the databases; the three-dimensional model loading module is used for directly performing graphic rendering on a bottom layer display card end through a GPU (graphics processing unit) by utilizing a WebGL open source three-dimensional visualization framework Cesum.js to realize loading and multidimensional display of basic terrain data, oblique photography model data and vector element data; the three-dimensional model analysis module is used for carrying out three-dimensional model analysis based on the loaded data, and comprises point location analysis, distance analysis, area analysis and gradient analysis of the three-dimensional model; the monomer module is used for adopting a vectorization method to carry out monomer.
Description
Technical Field
The invention relates to the technical field of urban real-scene three-dimensional display, in particular to a WebGIS (Web geographic information System) -based three-dimensional model data analysis display platform and a WebGIS-based three-dimensional model data analysis display method.
Background
WebGIS is a technology for expanding and perfecting geographic information system by using Web technology. It is a network-based client/server system; information exchange between the client and the server is performed by using the internet; it is a distributed system where users and servers can be distributed in different locations and on different computer platforms. WebGIS is mainly used for issuing spatial data, inquiring and retrieving space, serving space models, organizing Web resources and the like.
The oblique photography technique is a high and new technique developed in recent years in the international surveying and mapping field, and overcomes the limitation that the original orthoimage can only be shot from a vertical angle. It comprises the following characteristics: firstly, the actual situation of the ground object is reflected more truly in multiple angles; secondly, the texture of the side surface of the building can be collected, so that the urban three-dimensional modeling cost can be effectively reduced; thirdly, the data volume is small, and the network publishing is easy.
Based on WebGIS, the oblique photography technology is developed to generate a live-action three-dimensional model, and a live-action GIS platform combining the multi-source data and the three-dimensional GIS is constructed so as to comprehensively improve the comprehensive perception capability of the city, thereby strongly supporting the actual application of the business in each field of the city.
China with publication number CN111354084A specially adapted to 6/30/2020 discloses a network geographic information service system based on three-dimensional model tiles, which is applied to divide various visual data containing three-dimensional models to be displayed into tiles according to organization structures by slicing technology, store address information in a structure database, and connect a file database to combine with a local cache server when calling, so that three-dimensional models in a view range can be loaded rapidly, and the loading speed and efficiency of the three-dimensional models are improved. However, the patent application does not consider three-dimensional model analysis, and cannot provide measurement of urban environment livability and analysis of construction convenience points for road site selection.
The patent application discloses a WEB three-dimensional model data construction method disclosed in the Chinese patent application publication No. CN108228723A, which is exclusively owned by 2018, 6.29.8.8.A plurality of heterogeneous model data are subjected to format conversion, model data are unified, and a model slice construction process is unified; according to the spatial position relationship of the model, three-dimensional slice data is constructed, and massive model data are dynamically loaded in a slice mode under a WEB front-end three-dimensional platform; in the process of constructing the model slice, the model space information is separated from the attribute information and the model file, and the model file is called only under the condition that the front end needs to be rendered. The patent application focuses on the construction of three-dimensional model data, does not fully consider the analysis of the three-dimensional model, and does not consider the application of an oblique photography model.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a WebGIS-based three-dimensional model data analysis display platform and a WebGIS-based three-dimensional model data analysis display method, which realize the management, loading, visual display and analysis of DEM data, oblique photography model data and vector element data based on a B/S framework, and utilize an OpenGL-based GPU to accelerate a DSM extraction algorithm to perform gradient analysis, thereby expanding the application scene of an oblique photography model.
According to one aspect of the description of the invention, a WebGIS-based three-dimensional model data analysis display platform is provided, which comprises a data management module, a three-dimensional model loading module, a three-dimensional model analysis module and a monomer module; wherein the content of the first and second substances,
the data management module is used for constructing a tile file database, a PostGIS spatial database and a PostgreSQL database and respectively managing basic terrain data, oblique photography model data and vector element data according to different organization forms of the databases;
the three-dimensional model loading module is used for directly performing graphic rendering on a bottom layer display card end through a GPU (graphics processing unit) by utilizing a WebGL open source three-dimensional visualization framework Cesum.js to realize loading and multidimensional display of basic terrain data, oblique photography model data and vector element data;
the three-dimensional model analysis module is used for carrying out three-dimensional model analysis based on the loaded data, and comprises point location analysis, distance analysis, area analysis and gradient analysis of the three-dimensional model;
the monomer module is used for adopting a vectorization method to carry out monomer.
In the technical scheme, the basic terrain data, the oblique photography model data and the vector element data are respectively managed by constructing a tile file database, a PostGIS spatial database and a PostgreSQL database according to different organization forms of the databases; directly performing graphic rendering on a bottom layer display card end through a WebGL open source three-dimensional visualization framework Cesium.js, and respectively performing loading and visual display on basic terrain data, oblique photography model data and vector element data; carrying out three-dimensional analysis on the displayed model according to requirements, wherein the three-dimensional analysis comprises traditional point location analysis, distance analysis and area analysis, and gradient analysis for urban environment livability measurement and road construction site selection measurement; and finally, a vectorization method is adopted for carrying out singulation, so that the integration of the three-dimensional GIS and the two-dimensional GIS is realized while the effect is ensured and the original data and the LOD are not damaged.
As a further technical solution, the management of the basic terrain data includes: cropping DEM data obtained from the SRTM project; performing format conversion on all the cut large scene DEM files to obtain slice data; issuing http cache service by using a Caddy frame, and caching the slice data; and associating the cached slice data with a PostgreSQL database, and editing the cached slice data according to the organization form of the PostgreSQL database.
Particularly, the SRTM project can provide free DEM data with 30 m spatial resolution in the whole world, and the obtained DEM data are cut, so that the amount of stored data can be reduced, and the data access efficiency is improved. And carrying out format conversion on the cut data, and converting the cut data into a Quantized-mesh slice data format more suitable for network streaming transmission. Editing the cached slice data, wherein the edited fields comprise place names, land borders, administrative codes and the like.
As a further technical solution, the management of the oblique photography model data includes: acquiring three-dimensional mesh model data with textures generated by aerial triangulation after aerial photography by an unmanned aerial vehicle; converting mesh model data in an OSGB format into model data in a 3D title format; issuing http cache service by using a Caddy framework, and caching the model data in the 3D title format; and associating the cached 3D title format model data with a PostgreSQL database, and editing the 3D title format model data according to the organization form of the PostgreSQL database.
Specifically, the general format of the mesh model is OSGB format, and when the mesh model is released on the internet, it needs to be converted into 3d title format that is more suitable for internet streaming transmission and conforms to the OGC standard, so as to improve data access efficiency.
As a further technical solution, the managing of the vector element data includes: based on PostgreSQL database and PostGIS spatial database service, a vector element data spatial database is constructed, WFS service of vector element data is issued through an open-source GIS server GeoServer, and editing management of spatial data is achieved between the WFS service and a Web front end through a Rest API.
Specifically, on the basis of the existing administrative division element vector data, a vector element data space database is constructed on the basis of a PostgreSQL database and PostGIS space database service, wherein the administrative division vector element data comprises linear boundary data and also comprises punctuate data such as a monument and the like; in addition to the spatial data, the vector element data also contains correlation attribute data. The method and the system realize editing management functions of adding, deleting, modifying, checking and the like of the spatial data between the Web front end and the Web front end through the WFS service of the vector element data issued by the open-source GIS server GeoServer. On the basis, the method and the device also utilize the Caddy framework to provide http static cache service, and improve static space data access efficiency.
As a further technical solution, the gradient analysis includes: partitioning the large-scene three-dimensional model, and quickly generating initial DSM data of the relative elevations of the partitioned blocks by adopting an OpenGL elevation rendering mode for each partitioned block; performing relative elevation correction and data splicing by utilizing the overlapped area between the blocks; carrying out ray absolute elevation correction on the maximum elevation value and the minimum elevation value in the spliced DSM data to obtain global DSM data; slope analysis is performed in accordance with global DSM data.
According to the technical scheme, rendering acceleration is performed on the basis of an OpenGL display card, DSM (digital modeling system) rapid extraction is performed on large-scene OSGB (open graphics library) data, gradient analysis based on DSM data is achieved, and the problems that an existing DSM data extraction method is low in calculation efficiency and high in redundant data are solved. The purpose of gradient analysis is used for measuring the urban environment livable degree and the road construction site selection.
According to one aspect of the description of the invention, a three-dimensional model data analysis display method based on WebGIS is provided, which is realized based on the platform and comprises the following steps:
constructing a tile file database, a PostGIS spatial database and a PostgreSQL database, and respectively managing basic terrain data, oblique photography model data and vector element data according to different organization forms of the databases;
directly performing graphic rendering on a bottom layer display card end through a GPU (graphics processing Unit) by utilizing a WebGL open source three-dimensional visualization framework Cesum.js to realize loading and multidimensional display of basic terrain data, oblique photography model data and vector element data;
performing three-dimensional model analysis based on the loaded data, wherein the three-dimensional model analysis comprises point location analysis, distance analysis, area analysis and gradient analysis of the three-dimensional model;
and adopting a vectorization method to perform the singularization.
In the technical scheme, a plurality of databases are constructed by using a data management module of a platform so as to collect and manage basic terrain data, oblique photography model data and vector element data; loading basic topographic data and vector element data by using a three-dimensional model loading module, and loading oblique photography model data according to requirements; performing model analysis by using a three-dimensional model analysis module, wherein the model analysis comprises traditional point location analysis, distance analysis and area analysis, and gradient analysis for urban livable environment measurement and road construction site selection measurement; and finally, performing two-dimensional vector editing on the three-dimensional model by using a single module, and opening a key barrier between the three-dimensional inclined model and the two-dimensional vector plane by adopting a vector mask mode while ensuring the effect and not damaging the original data and the LOD.
As a further technical solution, the method further comprises: cropping DEM data obtained from the SRTM project; performing format conversion on all the cut large scene DEM files to obtain slice data; issuing http cache service by using a Caddy frame, and caching the slice data; and associating the cached slice data with a PostgreSQL database, and editing the cached slice data according to the organization form of the PostgreSQL database.
As a further technical solution, the method further comprises: acquiring three-dimensional mesh model data with textures generated by aerial triangulation after aerial photography by an unmanned aerial vehicle; converting mesh model data in an OSGB format into model data in a 3D title format; issuing http cache service by using a Caddy framework, and caching the model data in the 3D title format; and associating the cached 3D title format model data with a PostgreSQL database, and editing the 3D title format model data according to the organization form of the PostgreSQL database.
As a further technical solution, the method further comprises: the management of the vector element data includes: based on PostgreSQL database and PostGIS spatial database service, a vector element data spatial database is constructed, WFS service of vector element data is issued through an open-source GIS server GeoServer, and editing management of spatial data is achieved between the WFS service and a Web front end through a Rest API.
As a further technical solution, the method further comprises: partitioning the large-scene three-dimensional model, and quickly generating initial DSM data of the relative elevations of the partitioned blocks by adopting an OpenGL elevation rendering mode for each partitioned block; performing relative elevation correction and data splicing by utilizing the overlapped area between the blocks; carrying out ray absolute elevation correction on the maximum elevation value and the minimum elevation value in the spliced DSM data to obtain global DSM data; slope analysis is performed in accordance with global DSM data.
Specifically, the gradient analysis further includes: dynamically determining the content of a minimum block by using the width W, the height H and the resolution R according to the input OSGB data scene range, wherein an overlapping region of 1R exists between adjacent blocks; for single-block data, binding a DSM data storage area with an OpenGL depth buffer area in a rendering-to-texture mode, obtaining DSM data of a relative elevation stored in a rasterization mode by utilizing the rasterization of OpenGL, and writing the single-block DSM data of the relative elevation into a DSM folder under the same path with the original OSGB data; transmitting row, col and root directory root information to each thread in a multithreading mode according to data blocking information, and calculating relative elevation DSM data of each block; combining the calculated relative elevation DSM data of each block, and reconstructing elevation information of all blocks according to the preserved overlapping information when the data is blocked; and carrying out gradient analysis according to all the reconstructed DSM data.
Compared with the prior art, the invention has the beneficial effects that:
(1) the invention realizes the management, loading, visual display and analysis of DEM data, oblique photography model data and vector element data based on the B/S architecture, and a user can click the loaded data as required to visually display and analyze target data; and the invention realizes the loading and visual display of mass data by adopting asynchronous loading and cache optimization modes, improves the rendering efficiency and frame rate of the browser end, and greatly relieves the pause phenomenon caused by mass data loading and network transmission.
(2) According to the gradient analysis method, gradient analysis is performed by using the GPU acceleration DSM extraction algorithm based on OpenGL, the application scene of an oblique photography model is expanded, the problems of low calculation efficiency and high redundant data of the conventional DSM data extraction method are solved, and the efficiency of three-dimensional analysis is improved.
(3) The invention adopts a vectorization mode to carry out the singleization, realizes the integration of three-dimensional and two-dimensional GIS while ensuring the effect and not destroying the original data and LOD, can change the vector plane to be superposed at any time in the application process, and greatly improves the flexibility and the usability of the system.
Drawings
FIG. 1 is a schematic diagram of a WebGIS-based three-dimensional model data analysis display platform according to an embodiment of the invention.
Fig. 2 is a schematic diagram of basic terrain data management according to an embodiment of the present invention.
FIG. 3 is a schematic diagram of oblique photography model data management according to an embodiment of the present invention.
Fig. 4 is a schematic view of vector element data management according to an embodiment of the present invention.
Fig. 5 is a schematic diagram of OSGB data blocking according to an embodiment of the present invention.
FIG. 6 is a diagram of OpenGL fast extraction of relative elevation DSM data as monolithic data, according to an embodiment of the invention.
FIG. 7 is a diagram illustrating multi-block data DSM composite splicing, according to an embodiment of the invention.
Detailed Description
The technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is to be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.
According to an aspect of the present disclosure, a three-dimensional model data analysis display platform based on a WebGIS is provided, as shown in fig. 1, and includes a data management module, a three-dimensional model loading module, a three-dimensional model analysis module, and a singulation module; the data management module is used for constructing a tile file database, a PostGIS spatial database and a PostgreSQL database and managing basic terrain data, oblique photography model data and vector element data according to different organization forms of the databases; the three-dimensional model loading module is used for directly performing graphic rendering on a bottom layer display card end through a GPU (graphics processing unit) by utilizing a WebGL open source three-dimensional visualization framework Cesum.js to realize loading and multidimensional display of basic terrain data, oblique photography model data and vector element data; the three-dimensional model analysis module is used for carrying out three-dimensional model analysis based on the loaded data, and comprises point location analysis, distance analysis, area analysis and gradient analysis of the three-dimensional model; the monomer module is used for adopting a vectorization method to carry out monomer.
As an implementation manner, the analysis and display platform of this embodiment manages the basic terrain data, as shown in fig. 2, including: cropping DEM data acquired from an SRTM project, wherein the SRTM project can provide free DEM data with 30 m spatial resolution in the world; performing format conversion on all the cut large scene DEM files to obtain slice data; issuing http cache service by using a Caddy frame, and caching the slice data; and associating the cached slice data with a PostgreSQL database, and editing the cached slice data according to the organization form of the PostgreSQL database, wherein the edited fields comprise place names, place boundaries, administrative codes and the like.
As an embodiment, the analysis display platform of this embodiment manages oblique photography model data, as shown in fig. 3, including: acquiring three-dimensional mesh model data with textures generated by aerial triangulation after aerial photography by an unmanned aerial vehicle; converting mesh model data in an OSGB format into model data in a 3D title format; issuing http cache service by using a Caddy framework, and caching the model data in the 3D title format; and associating the cached 3D title format model data with a PostgreSQL database, and editing the 3D title format model data according to the organization form of the PostgreSQL database.
As an embodiment, the analysis display platform of this embodiment manages vector element data, as shown in fig. 4, and includes: based on PostgreSQL database and PostGIS spatial database service, a vector element data spatial database is constructed, WFS service of vector element data is issued through an open-source GIS server GeoServer, and editing management of spatial data is achieved between the WFS service and a Web front end through a Rest API. In the embodiment, on the basis of the existing administrative division element vector data, a vector element data space database is constructed based on a PostgreSQL database and a PostGIS space database service, wherein the administrative division vector element data comprises linear boundary data and also comprises punctuate data such as a landmark; in addition to the spatial data, the vector element data also contains correlation attribute data. In the embodiment, the WFS service of the vector element data is issued by the open-source GIS server GeoServer, and the editing management functions of adding, deleting, modifying, checking and the like of the spatial data are realized between the Web front end and the Web front end through the Rest API. On the basis, the method and the device also utilize the Caddy framework to provide http static cache service, and improve static space data access efficiency.
As an implementation manner, the analysis display platform of the embodiment performs slope analysis, including: partitioning the large-scene three-dimensional model, and quickly generating initial DSM data of the relative elevations of the partitioned blocks by adopting an OpenGL elevation rendering mode for each partitioned block; performing relative elevation correction and data splicing by utilizing the overlapped area between the blocks; carrying out ray absolute elevation correction on the maximum elevation value and the minimum elevation value in the spliced DSM data to obtain global DSM data; slope analysis is performed in accordance with global DSM data. According to the technical scheme, rendering acceleration is performed on the basis of an OpenGL display card, DSM (digital modeling system) rapid extraction is performed on large-scene OSGB (open graphics library) data, gradient analysis based on DSM data is achieved, and the problems that an existing DSM data extraction method is low in calculation efficiency and high in redundant data are solved. The purpose of gradient analysis is used for measuring the urban environment livable degree and the road construction site selection.
According to one aspect of the description of the invention, a three-dimensional model data analysis display method based on WebGIS is provided, which is realized based on the platform and comprises the following steps:
step 1, a tile file database, a PostGIS spatial database and a PostgreSQL database are constructed, and basic terrain data, oblique photography model data and vector element data are managed according to different organization forms of the databases.
The DEM data in this embodiment is sourced as SRTM entries that provide free DEM data at 30 meters spatial resolution globally. After the DEM is acquired, in the three-dimensional data management system of this embodiment, the downloaded DEM is cut to reduce the amount of stored data and improve the data access efficiency. After cutting, format conversion is carried out on all large scene DEM files, and the large scene DEM files are converted into Quantized-mesh slice data. The format of such tile data is more suitable for network streaming than the original format. On this basis, the embodiment utilizes the Caddy framework to issue the corresponding http cache service, and directly associates with the Postgresql database of the platform, edits the relevant fields, and finally performs three-dimensional terrain display in the three-dimensional analysis display subsystem.
The oblique photography three-dimensional model in the platform is a three-dimensional mesh model with textures generated by aerial triangulation after aerial photography by an unmanned aerial vehicle. The universal format of the model is OSGB, when the model is released on the Internet, the model needs to be converted into a 3D title format which is more suitable for Internet streaming transmission and accords with the OGC standard, and the data access efficiency is improved. On the basis, the platform utilizes a Caddy framework to issue corresponding http cache service, directly associates with the Postgresl database of the embodiment, edits related fields, and finally displays the oblique photography three-dimensional model in the three-dimensional analysis display subsystem.
In the embodiment, on the basis of the existing administrative division element vector data, a vector element data space database is constructed on the basis of a Postgresql database and a PostGIS space database service, and a vector element data management function is provided. The administrative division vector element data comprises linear boundary line data and punctuate data such as a landmark; in addition to the spatial data, the vector element data also contains correlation attribute data. In the embodiment, the WFS service of the vector element data is issued by the open-source GIS server GeoServer, and the editing management functions of adding, deleting, modifying, checking and the like of the spatial data are realized between the Web front end and the Web front end through the Rest API. On this basis, the embodiment provides http static cache service by using the Caddy framework, and improves static spatial data access efficiency.
Step 2, in the embodiment, WebGL is used as a 3D drawing standard, JavaScript API is used to perform three-dimensional model visualization, and hardware 3D accelerated rendering is provided for HTML5 Canvas. And (3) performing graphic rendering on a bottom layer display card end directly through a GPU (graphics processing unit) by utilizing a WebGL open source three-dimensional visualization framework Cesium.
And 3, carrying out three-dimensional model analysis based on the loaded data, wherein the three-dimensional model analysis comprises point location analysis, distance analysis, area analysis and gradient analysis of the three-dimensional model.
The point location analysis, distance analysis and area analysis of this embodiment are performed by converting screen coordinates into WGS84 coordinates using a ceium open source API, and performing distance and area analysis based on a spherical distance formula and a spherical polygon area formula.
The slope analysis described in this embodiment is implemented based on DSM data extracted quickly from large-scene OSGB data, and the specific steps are as follows:
step 3.1OSGB data blocking
The minimum blocking content is dynamically determined according to the input OSGB data scene range, including width (W, unit m), height (H, unit m) and resolution R (m). The block data is indexed using a list in which path, number and range information for each block file is stored. The numbering takes the form of binary numbering, i.e. (rows, columns). And storing the model after the blocking is finished to a Tiles folder in the same path, wherein the naming format is row-col. And after the blocking is finished, writing the number information and the range information into a meta text file under the same path of the OSGB so as to be used in steps 3.2,3.3 and 3.4.
For adjacent tiles, it needs to be guaranteed to have an overlap region of 1 × R according to resolution. The overlapping area exists to account for DSM relative elevation agreement for adjacent areas in the DSM, as shown in fig. 5.
Step 3.2 Single-tile data OpenGL DSM for rapidly extracting relative elevation
For a single Tile, DSM information of its relative elevation is closely related to depth information in OpenGL. In the algorithm, an RTT technology (rendering to texture) is adopted, a DSM data storage area is bound with an OpenGL depth buffer area, and DSM data of a relative elevation of rasterized storage (0-255) is quickly obtained by using a rasterization technology of OpenGL. And after the processing is finished, writing the relative elevation DSM data of the block into a DSM folder under the same path with the original OSGB, wherein the file naming mode is row-col.
As shown in fig. 6, the specific implementation steps are as follows:
1) constructing a Tile path as root + "/Tiles/" + row + "-" + col + ". osgb according to the transferred row, col and the root directory root of the model;
2) reading the model, binding the model to a camera node, and setting a camera rendering mode as RTT rendering;
3) according to the model size (h, w) and the resolution information (r), applying for a corresponding memory, and calculating the memory size in the mode of
dsm_cache_size＝ceil(h/r)*ceil(w/r)*sizeof(float32)
Wherein ceil is rounding up, sizeof is calculating the number of bytes of the corresponding data type;
4) binding the applied memory to a depth buffer area of OpenGL;
5) clearing the data of the depth buffer area, and forcing the camera to render 5 frames (5 frames are experimental parameters, which can ensure that all areas of the Tile are calculated once);
6) unbinding depth buffering, ending rendering, and releasing the memory occupied by the model;
7) saving the Dsm data to root + "/Dsm/" + row + "-" + col + ". tif, and storing in a single-waveband grid type of GeoTiff;
8) and releasing the dsm memory and informing the main thread of finishing the process.
Step 3.3 parallel computing Single Tile DSM
And (3) transmitting row, col and root directory root information to each thread in a multithreading mode according to the OSGB information segmented in the step 3.1, and operating as shown in the step 3.2. When the DSM calculation and saving for all tiles is complete, step 3.4 is performed.
Step 3.4 Multi-Tile data DSM composition splicing
The DSMs of all blocks obtained in step 3.3 are combined. The data in the OpenGL buffer area has a range of normalized depth values and a numerical range of 0-1. The normalization is performed in a block max-min normalization manner, so that the DSM data of each Tile is relative elevation. The key points of the step are as follows: and (4) reconstructing elevation information of all tiles according to the reserved overlapping information in the step 3.1. As shown in fig. 7.
The method comprises the following specific steps:
1) creating a total DSM file according to the range and the resolution of the total model;
2) starting from the upper left corner, i.e. setting row to 0 and col to 0, steps 3-5 are performed in sequence;
3) read DSM data of row-col. tif, if row is 0 and col is 0, col increments by 1, continue to step 3), otherwise step 4);
4) and if the row is equal to 0, calculating a transformation parameter of an overlapped part between the row-col and the row-col-1 block in a least square method in a linear formula Y equal to AX, and transforming the data in the row-col block into the row-col-1. If the row is more than 0, calculating transformation parameters of the overlapping parts of the row-col and the row-col-1 and the row-1-col;
5) col increases by 1, col becomes 0 when col reaches the maximum, and row increases by 1. If row reaches the maximum and col reaches the maximum, entering the step 6), otherwise, returning to the step 3);
6) calculating absolute elevation values corresponding to the maximum elevation value and the minimum elevation value in the model by adopting a ray method, and globally converting DSM data of relative elevation into DSM data of absolute elevation by utilizing linear mapping transformation;
7) writing the transformation parameters and DSM data into a dsm.GIF file and releasing a memory;
8) the program ends, resulting in a DSM extraction result.
And 3.5, carrying out gradient analysis according to all the reconstructed DSM data, and measuring the urban environment suitable for living or measuring the road site selection location.
And 4, adopting a vectorization method to perform singularization. The method has the advantages that the single module is utilized to carry out two-dimensional vector editing on the three-dimensional model, and the vector mask mode is adopted, so that the key level between the three-dimensional inclined model and the two-dimensional vector plane is opened while the effect is ensured and the original data and the LOD are not damaged.
In the description herein, references to the description of the terms "one embodiment," "certain embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention.
Claims (8)
1. The WebGIS-based three-dimensional model data analysis and display platform is characterized by comprising a data management module, a three-dimensional model loading module, a three-dimensional model analysis module and a monomer module; wherein the content of the first and second substances,
the data management module is used for constructing a tile file database, a PostGIS spatial database and a PostgreSQL database and respectively managing basic terrain data, oblique photography model data and vector element data according to different organization forms of the databases;
the three-dimensional model loading module is used for directly performing graphic rendering on a bottom layer display card end through a GPU (graphics processing unit) by utilizing a WebGL open source three-dimensional visualization framework Cesum.js to realize loading and multidimensional display of basic terrain data, oblique photography model data and vector element data;
the three-dimensional model analysis module is used for carrying out three-dimensional model analysis based on the loaded data, and comprises point location analysis, distance analysis, area analysis and gradient analysis of the three-dimensional model;
the gradient analysis comprises: partitioning the large-scene three-dimensional model, and quickly generating initial DSM data of the block relative elevation by adopting an OpenGL elevation rendering mode for each partition; performing relative elevation correction and data splicing by utilizing the overlapped area between the blocks; carrying out ray absolute elevation correction on the maximum elevation value and the minimum elevation value in the spliced DSM data to obtain global DSM data; performing slope analysis according to global DSM data; the slope analysis further includes: dynamically determining the content of a minimum block by using the width W, the height H and the resolution R according to the input OSGB data scene range, wherein an overlapping region of 1R exists between adjacent blocks; for single-block data, binding a DSM data storage area with an OpenGL depth buffer area in a rendering-to-texture mode, obtaining DSM data of a relative elevation stored in a rasterization mode by utilizing the rasterization of OpenGL, and writing the single-block DSM data of the relative elevation into a DSM folder under the same path with the original OSGB data; transmitting row, col and root directory root information to each thread in a multithreading mode according to data blocking information, and calculating relative elevation DSM data of each block; combining the calculated relative elevation DSM data of each block, and reconstructing elevation information of all blocks according to the preserved overlapping information when the data is blocked; carrying out gradient analysis according to all the reconstructed DSM data;
the monomer module is used for adopting a vectorization method to carry out monomer.
2. The WebGIS-based three-dimensional model data analysis display platform according to claim 1, wherein the management of the basic terrain data comprises: cropping DEM data obtained from the SRTM project; performing format conversion on all the cut large scene DEM files to obtain slice data; issuing http cache service by using a Caddy frame, and caching the slice data; and associating the cached slice data with a PostgreSQL database, and editing the cached slice data according to the organization form of the PostgreSQL database.
3. The WebGIS-based three-dimensional model data analysis display platform according to claim 1, wherein the management of the oblique photography model data comprises: acquiring three-dimensional mesh model data with textures generated by aerial triangulation after aerial photography by an unmanned aerial vehicle; converting mesh model data in an OSGB format into model data in a 3D title format; issuing http cache service by using a Caddy framework, and caching the model data in the 3D title format; and associating the cached 3D title format model data with a PostgreSQL database, and editing the 3D title format model data according to the organization form of the PostgreSQL database.
4. The WebGIS-based three-dimensional model data analysis and display platform according to claim 1, wherein the management of the vector element data comprises: based on PostgreSQL database and PostGIS spatial database service, a vector element data spatial database is constructed, WFS service of vector element data is issued through an open-source GIS server GeoServer, and editing management of spatial data is achieved between the WFS service and a Web front end through a Rest API.
5. The three-dimensional model data analysis and display method based on the WebGIS is realized on the basis of the platform of any one of claims 1 to 4, and is characterized by comprising the following steps of:
constructing a tile file database, a PostGIS spatial database and a PostgreSQL database, and respectively managing basic terrain data, oblique photography model data and vector element data according to different organization forms of the databases;
directly performing graphic rendering on a bottom layer display card end through a GPU (graphics processing Unit) by utilizing a WebGL open source three-dimensional visualization framework Cesum.js to realize loading and multidimensional display of basic terrain data, oblique photography model data and vector element data;
performing three-dimensional model analysis based on the loaded data, wherein the three-dimensional model analysis comprises point location analysis, distance analysis, area analysis and gradient analysis of the three-dimensional model;
and adopting a vectorization method to perform the singularization.
6. The WebGIS-based three-dimensional model data analysis and display method according to claim 5, further comprising the steps of: cropping DEM data obtained from the SRTM project; performing format conversion on all the cut large scene DEM files to obtain slice data; issuing http cache service by using a Caddy frame, and caching the slice data; and associating the cached slice data with a PostgreSQL database, and editing the cached slice data according to the organization form of the PostgreSQL database.
7. The WebGIS-based three-dimensional model data analysis and display method according to claim 5, further comprising the steps of: acquiring three-dimensional mesh model data with textures generated by aerial triangulation after aerial photography by an unmanned aerial vehicle; converting mesh model data in an OSGB format into model data in a 3D title format; issuing http cache service by using a Caddy framework, and caching the model data in the 3D title format; and associating the cached 3D title format model data with a PostgreSQL database, and editing the 3D title format model data according to the organization form of the PostgreSQL database.
8. The WebGIS-based three-dimensional model data analysis and display method according to claim 5, further comprising the steps of: the management of the vector element data includes: based on PostgreSQL database and PostGIS spatial database service, a vector element data spatial database is constructed, WFS service of vector element data is issued through an open-source GIS server GeoServer, and editing management of spatial data is achieved between the WFS service and a Web front end through a Rest API.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011636521.8A CN112686997B (en) | 2020-12-31 | 2020-12-31 | WebGIS-based three-dimensional model data analysis display platform and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011636521.8A CN112686997B (en) | 2020-12-31 | 2020-12-31 | WebGIS-based three-dimensional model data analysis display platform and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112686997A CN112686997A (en) | 2021-04-20 |
| CN112686997B true CN112686997B (en) | 2021-11-09 |
Family
ID=75456453
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011636521.8A Active CN112686997B (en) | 2020-12-31 | 2020-12-31 | WebGIS-based three-dimensional model data analysis display platform and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112686997B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113311856A (en) * | 2021-05-31 | 2021-08-27 | 中煤航测遥感集团有限公司 | Unmanned aerial vehicle data management method, device, equipment and storage medium |
| CN114170394B (en) * | 2021-12-03 | 2023-07-04 | 北京数字政通科技股份有限公司 | Method and device for optimizing display of massive inclined data on Web end |
| CN115170749B (en) * | 2022-06-01 | 2023-09-22 | 山东翰林科技有限公司 | WEBGIS three-dimensional visualization construction method and system based on Cesium |
| CN115114356B (en) * | 2022-06-28 | 2023-03-21 | 河北平普数政科技有限公司 | Real-time decryption method based on vector data front-end display |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111274337A (en) * | 2019-12-31 | 2020-06-12 | 北方信息控制研究院集团有限公司 | Two-dimensional and three-dimensional integrated GIS system based on live-action three-dimension |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110188989A (en) * | 2019-04-21 | 2019-08-30 | 北京工业大学 | One kind being based on three-dimensional visualization outdoor scene wisdom municipal administration system |
-
2020
- 2020-12-31 CN CN202011636521.8A patent/CN112686997B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111274337A (en) * | 2019-12-31 | 2020-06-12 | 北方信息控制研究院集团有限公司 | Two-dimensional and three-dimensional integrated GIS system based on live-action three-dimension |
Non-Patent Citations (3)
| Title |
|---|
| 三维WebGIS支持下的城市规划辅助决策系统的设计与实现;任飞翔;《中国优秀硕士学位论文全文数据库 基础科学辑》;20200215;A008-134 * |
| 基于Cesium的三维实景可视化技术研究;李俊金;《中国优秀硕士学位论文全文数据库-基础科学辑》;20180615;A008-133 * |
| 基于开源 W ebG IS 的三维自然资源管理平台的设计与实现;赵栋梁;《科学技术创新》;20201130;第104-105页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112686997A (en) | 2021-04-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112686997B (en) | WebGIS-based three-dimensional model data analysis display platform and method | |
| CN105701103B (en) | Three-dimensional application system based on geographic information | |
| CN101388043B (en) | OGC high performance remote sensing image map service method based on small picture | |
| KR101546703B1 (en) | System for processing massive bim data of building | |
| KR101546705B1 (en) | Method for visualizing building-inside bim data by bim data process terminal | |
| CN110969691B (en) | WebGL-based photographic data scheduling method and system | |
| Liang et al. | Embedding user-generated content into oblique airborne photogrammetry-based 3D city model | |
| CN111881238A (en) | Lightweight three-dimensional data construction method and medium suitable for Web end and electronic device | |
| CN112925865B (en) | 3D WebGIS prediction analysis method and system for mining area ground surface movement deformation | |
| US9311748B2 (en) | Method and system for generating and storing data objects for multi-resolution geometry in a three dimensional model | |
| CN103309943A (en) | Three-dimensional geographic information platform and topographic data processing method thereof | |
| Caradonna et al. | Multi-image 3D reconstruction: a photogrammetric and structure from motion comparative analysis | |
| Yu et al. | A hybrid system of expanding 2D GIS into 3D space | |
| Deibe et al. | GVLiDAR: an interactive web-based visualization framework to support geospatial measures on lidar data | |
| Rechichi | Chimera: a BIM+ GIS system for cultural heritage | |
| CN116467540B (en) | HBase-based massive space data rapid visualization method | |
| Guney | Rethinking GIS towards the vision of smart cities through CityGML | |
| CN115689886A (en) | Distributed slicing method and distributed slicing device for framing images | |
| Glander et al. | Automated cell based generalization of virtual 3D city models with dynamic landmark highlighting | |
| El Haje et al. | 3D cities rendering and visualisation: a web-based solution | |
| Baek et al. | Geometric primitive extraction from LiDAR-scanned point clouds | |
| Zhang et al. | Web-based terrain and vector maps visualization for Wenchuan earthquake | |
| Gruber et al. | Urban data management—A modern approach | |
| Que et al. | Realistic 3D terrain roaming and real-time flight simulation | |
| CN111784840B (en) | LOD (line-of-sight) level three-dimensional data singulation method and system based on vector data automatic segmentation |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |