Method for accessing 3dtiles data based on SQLite

Abstract

The application discloses an access method of 3DTiles data based on SQLite, and relates to the field of data access, and comprises the following steps: S1, a remote terminal is operated to obtain 3DTiles data files; S2, the values of corresponding fields in the directory structure of a database are obtained according to the name of a Tile directory, and the content of a tileset.json file is converted into corresponding data values in the table structure of the database; S3, corresponding values are obtained according to the directory structure and stored in a storage module of the remote terminal; S4, the remote terminal is operated to be communicatively connected with a cloud server, and the directory structure in the storage module is stored into an SQLite database; S5, the remote terminal is read and communicatively connected with the cloud server; S6, data is requested from the cloud server according to a current display view range; and S7, the data fed back by the cloud server is read and publishing service is performed; SQLite is a light relational database, and the resource occupation is very low, so when 3DTiles data in a specified range is read, the access speed can be improved, and even the response request can reach several milliseconds, so that the rendering speed of a three-dimensional map is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of data access, and in particular to a method for accessing 3DTiles data based on SQLite. BACKGROUND

[0002] 3D Tiles is an open standard for 3D spatial data such as oblique photography, 3D buildings, point clouds, etc. The purpose of its design is mainly to improve the loading and rendering speed of models in a 3D scene. Existing 3DTiles data management is generally folder management, and there is also management based on HBase database. The former has low data reading efficiency, and the latter is a non-relational database, so as the data volume increases, the efficiency of reading a specified range will also become slower and slower, ultimately affecting the loading and rendering speed of 3D data. In addition, the data publishing is also complex, with many steps, slow publishing speed, and inconvenient installation. SUMMARY

[0003] The purpose of the present application is to design a method for accessing 3DTiles data based on SQLite to solve the above problems.

[0004] The present application achieves the above-mentioned purpose through the following technical solutions:

[0005] The method for accessing 3DTiles data based on SQLite, the SQLite database is located in a cloud server, comprising:

[0006] S1, operating a remote terminal to obtain a 3DTiles data file;

[0007] S2, in the 3DTiles data file directory, according to the name of the Tile directory, obtaining the value of the corresponding field in the directory structure of the database, and converting the content of the tileset.json file into the corresponding data value in the table structure of the database;

[0008] S3, according to the directory structure, obtaining the corresponding value and storing it in the storage module of the operating remote terminal;

[0009] S4, the operating remote terminal is in communication connection with the cloud server, and the directory structure in the storage module is stored into the SQLite database;

[0010] S5, a reading remote terminal for reading data is in communication connection with the cloud server;

[0011] S6, according to the range of the current display view of the reading remote terminal, requesting the 3DTiles data file in the SQLite database from the cloud server;

[0012] S7, reading the remote terminal reads the data feedback of the cloud server and performing publishing service.

[0013] The application has the beneficial effect of providing an access method for 3DTiles data based on SQLite. SQLite is a lightweight relational database with very low resource occupation, so when reading 3DTiles data in a specified range, the access speed can be improved, and even the response request can be achieved within a few milliseconds, improving the rendering speed of the three-dimensional map. At the same time, the data is based on a file-based relational database, and publishing does not require the installation of a database, which has the characteristics of convenient and fast deployment. DETAILED DESCRIPTION

[0014] In addition, the terms "first", "second", etc. are only used for differentiation and description, and cannot be understood as indicating or implying relative importance.

[0015] In the description of the application, it should be noted that, unless otherwise explicitly specified and limited, the terms "set", "connected" and the like should be understood in a broad sense, for example, "connected" can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; or can be the communication between two elements inside. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0016] The specific embodiments of the application will be described in detail below.

[0017] The access method for 3DTiles data based on SQLite, the SQLite database is located in the cloud server, comprising:

[0018] S1, operating a remote terminal to obtain a 3DTiles data file;

[0019] S2, in the 3DTiles data file directory, according to the name of the Tile directory, the value of the corresponding field in the directory structure of the database is obtained, such as Tile_+000_+010_L15_00020t3.b3dm, 000 is column, 010 is row, L15 is level, and 00020t3 is index value, the content of the tileset.json file is converted into the corresponding data value in the table structure of the database, such as boundingVolume and geometricError are obtained according to the data of the node in tileset.json, the content data of the tile is a binary file, according to different types of data, which may be batch 3D model (b3dm), 3D model instance (i3dm), point cloud (pnts), composite image (cmpt) and the like; the table structure includes column, row, scaling level, stored tile content data, bound bounding volume, geometric error, and index of tile data, wherein column, row, level, and geometricError are indexed;

[0020] S3, according to the directory structure, the corresponding value is obtained, a unique identification is generated by operating a remote terminal, and the unique identification is assigned to the directory structure to be stored in the SQLite database, and the unique identification is stored in the storage module of the operating remote terminal together with the directory structure;

[0021] S4, the operating remote terminal is in communication connection with the cloud server, and the directory structure in the storage module is stored in the SQLite database by using multi-thread technology, one thread processes one directory, and the multi-thread technology can improve the speed of file reading and writing and storage; when the directory structure is stored in the SQLite database, the unique identification is transmitted first, and then the directory is stored in the SQLite database; when the transmission is interrupted, the transmission is connected again, the unique identification is identified, the directory structure is stored in the same position in the SQLite database, and the same directory with the same identification can be covered when the directory is transmitted again, so that the space of the SQLite database is not wasted, and the identification is read and transmitted when the data is read subsequently;

[0022] S5, the reading remote terminal for reading data is in communication connection with the cloud server;

[0023] S6, according to the range of reading the current display view of the remote terminal, request the 3DTiles data file in the SQLite database to the cloud server; the remote terminal requests the 3DTiles data file in the SQLite database to the cloud server in the following three filtering ways;

[0024] ①, according to the range of the current display view, calculate the range value of row, column and zoom level;

[0025] ②, according to the range of the current display view, filter the value of the boundary volume;

[0026] ③, according to the range of the current display view, filter the geometric error value.

[0027] The result set of the intersection of the three ways is the spatial three-dimensional data required by the current view to be loaded, the data required by filtering query is removed to speed up the data transmission and the speed of subsequent rendering

[0028] S7, read the data fed back by the cloud server read by the remote terminal, and carry out publishing service; different dynamic link libraries can directly read the data and publish the service, so the deployment program does not need to install the database program, and therefore the data publishing is simple and fast.

[0029] The technical scheme of the application is not limited to the above specific embodiments, and any technical modification made according to the technical scheme of the application falls within the protection scope of the application.

Claims

1. A method for accessing 3DTiles data based on SQLite, where the SQLite database is located on a cloud server, characterized in that: include: S1. Operate the remote terminal to obtain 3DTiles data files; S2. In the 3DTiles data file directory, obtain the value of the corresponding field in the directory structure of the database according to the name of the Tile directory, and convert the content of the tileset.json file into the corresponding data value in the table structure of the database. The table structure includes column column, row row, zoom level level, stored tile content data data, bounding volume boundingVolume, geometric error geometricError, and tile data index, where indexes are established for the column, row, level, and geometricError fields. S3. Obtain corresponding values ​​according to the directory structure and store them in a storage module of the remote terminal; S4. Operate the remote terminal to communicate with the cloud server and store the directory structure in the storage module into the SQLite database; S5. The remote terminal for reading data is connected to the cloud server for communication; S6. Requesting the 3DTiles data file in the SQLite database from the cloud server according to the range of the current display view read from the remote terminal; S7. The remote terminal reads the data fed back by the cloud server and publishes the service.

2. The method for accessing 3DTiles data based on SQLite according to claim 1, characterized in that: In S6, the remote terminal uses the following three filtering methods to request the 3DTiles data file in the SQLite database from the cloud server; ① Calculate the range values ​​of rows, columns, and zoom levels based on the range of the current display view; ②Filter the bounding volume value according to the range of the current display view; ③Filter the geometric error value according to the range of the current display view.

3. The method for accessing 3DTiles data based on SQLite according to claim 1, characterized in that: In S4, the remote terminal uses multi-threading technology to store all directories in the SQLite database, with one thread processing one directory.

4. The method for accessing 3D Tiles data based on SQLite according to claim 1, characterized in that: In S3, the remote terminal is operated to generate a unique identification identifier, and the unique identification identifier is assigned to the directory structure to be stored in the SQLite database, and is stored in the SQLite database together.

5. The SQLite-based 3DTiles data access method according to claim 4, characterized in that: In S4, when storing a directory structure in an SQLite database, a unique identification identifier is first transmitted, and then the directory is stored in the SQLite database; when transmitting a directory, the same directory with the same identification identifier can be overwritten.