Vector Tile Production

Feature Description

Supports generating vector tiles that comply with the MapBox MVT specification from vector maps. Tile data includes the geometric shapes and attributes of features, while the style of features is described by the MapBox standard style file (style.json). Compared to raster tiles, vector tiles have advantages such as seamless zooming, style modification, and relatively smaller data volume, better meeting the needs of flexible and diverse web map applications. For descriptions and comparisons of raster tiles and vector tiles, please refer to the Map Tile Types: page. The following takes generate map tiles (single process) as an example to illustrate the steps.

Function Entry

  • Workspace Manager -> Map node -> Right-click on the map that needs to generate map tiles -> Generate Map Tiles (Single Process) item.
  • Right-click on the map and select Generate Map Tiles (Single Process) item.
  • Map tab -> Cartography group -> Single Process.

Operation Steps

  1. New Tiling Task: In the Generate Map Tiles (Single Process) dialog box, you can choose three single-process map cache methods: new tiling task, update/append tiles, resume/restore tiles. Here, select the New Tiling Task item.
  2. Set Scale Information: In the Single Process: Generate Map Tiles dialog box, set the scale parameters for generating tiles. The program will automatically generate a scale list based on the map data. You can modify the scale information through the scale toolbar, including switching scale schemes, adding scales, importing/exporting scale configuration files or tile configuration files.
    Tip:
    • The tile configuration file (*.sci) saves the scales for generating map tiles and other tile production parameters.
    • The scale configuration file only records scale information.
  3. Parameters:
    • Tile Type:: Select vector tile.
    • The Size of Tiles: The size of each generated tile, in pixels (PX). Options are 512*512 and 256*256, with a default size of 512*512.
    • Tile Range: Set the tile range. Each tile expands outward according to the set range value, meaning the generated tiles include data within the buffer range. Setting the tile range ensures seamless connection between adjacent tiles when browsing. The default value is 16, in pixels.
    • Rarefy Display: Check this parameter to simplify geometries at small scales, improving display performance. Uncheck to disable simplification.
    • Generate Index: Unchecked by default. If vector polygons exist in the generated vector tiles, they will be triangulated, and this triangulation index will be generated to accelerate loading speed in WebGL.

    • Set Up a 3D Building: Used to configure the display effects of 3D buildings in tiles. This function is only available when the tiling scale is Global Scale and Generate Tiles Style is checked. Starting Display Level, Ending Display Level, Building Color, Transparency: and Custom Style will be uniformly applied to all datasets in the table.

      • Toolbar Functions:

        • Add: Add a new record in the table to set up a 3D building for the corresponding dataset.

        • Delete: Remove dataset records that do not require 3D building display.

        • Import: Import an XML file containing parameter configuration information.

        • Export: Export all current interface parameters to an XML file, facilitating reuse and avoiding repeated settings.

      • Table Header Description:

        • Datasource: By default, selects the data source linked to the first polygon layer in the current map. Only data sources associated with existing polygon layers in the current map can be selected.

        • Dataset: By default, selects the dataset related to the first polygon layer in the current map. Only region datasets added to the current map are supported.

        • Bottom Elevation Value: Set the starting Z-coordinate for the 3D building on the Z-axis. Supports entering a fixed value or selecting a property field as the elevation source.

        • Top Elevation Value: Set the ending elevation for the 3D building on the Z-axis. Supports entering a fixed value or selecting a property field as the elevation source.

      • Starting Display Level: The level at which 3D buildings start to display, with a default value of 16 and a range of [0,23].

      • Ending Display Level: The level at which 3D buildings stop displaying, with a default value of 19 and a range of [1,24]. The ending display level must be greater than the starting display level.

      • Building Color: Set the display color of the 3D building in the resulting tiles.

      • Transparency (%): Adjust the transparency of the 3D building, with a default value of 0.

      • Custom Style: Enter a valid Mapbox style JSON string to define the display style (e.g., {"fill-extrusion-translate":[50,50]}). Separate multiple styles with English commas; if custom styles conflict with built-in styles, built-in styles take precedence; this function is only compatible with Mapbox GL JS versions 0.27.0 to 1.x, not compatible with versions 2.x and above.

  4. Output Field Settings:
    • Output All Fields: When selected, the generated tile results include all non-system fields carried by the corresponding dataset's geometry, except binary and byte-type fields which are not supported. When a layer has many fields, generation efficiency may slow down.
    • Customize the Output: Used to set the output fields for layers generating vector tiles. You can customize the output fields, remove redundant data, effectively reduce tile volume, and improve transmission and loading performance. For how to set output fields, please refer to the relevant instructions in the: Set Vector Layer Properties document.
  5. Output Result Settings:
    • Generate Vector Tile: Checked by default to generate vector tiles, with results stored in the tiles folder. Not available when using generate tile by multi-process.
    • Generate Tiles Style: Checked by default. Generate a *.json file containing the corresponding map style, with results stored in the sprites and styles folders. Not available when using generate tile by multi-process.
    • Separate Data from Style: Used to set whether to store vector tile data and style separately.
      • Check this parameter to separate vector tile data and style, allowing convenient and flexible updates to tile data and style. However, vector tile data at each level includes the full dataset of the layer, resulting in larger tile volume.
      • Uncheck, which is the default, meaning data and style are not separated. Vector tile data at each level only includes the displayed data of the layer, effectively reducing tile volume.
    • Generate Font Cache File: Used to generate font files for the map, checked by default, with results stored in the fonts folder.
  6. Save Settings:
    • Tile Name: The name of the folder for generated tiles, default is the map name. When a tile with that name already exists in the storage path, clicking the Next button will prompt, e.g., "The 'China100_2021' file already exists, please re-enter the tile name or storage path."
    • Storage Format: Provides three storage formats: Compact, Original, and MongoDB. For detailed descriptions of storage formats, please see Tile Storage Format.
      • When selecting Original or Compact, the storage method needs to be set.
      • When selecting MongoDB, you need to set the server address, database name, and optionally set a password for the tiles.
        Notes:

        The authentication mode of MongoDB version 2.0 does not support generating map tiles. For using MongoDB databases, please refer to MongoDB Instructions for Use.

    • Storage Method: The storage method for generated tiles, with two options: Local and Cloud.
      • Select Local, and the generated tiles and intermediate files will be stored in the local path specified by the storage path.
      • Select Cloud Storage, and you can choose a cloud storage path in the storage path to store tile files. Before using a cloud storage path, you need to first Add Cloud Storage Connection; simultaneously, set the working directory. Intermediate files generated during tiling will be stored in the local path specified by the working directory.
    • Storage Path: The storage path for generated tiles.
    • Working Directory: Required when the storage method is Cloud Storage or the storage format is MongoDB. Used to store intermediate files generated during tiling, facilitating resumption and tile updates.
  7. Tile Bounds: Set the geographic range of the map data. The program will generate map tiles according to this range. The following setting methods are provided:
    • Whole Map: Use the whole map's range as the tile bounds. The four text boxes (left, bottom, right, top) display the set processing range.
    • Current Window: Use the current window's range as the tile bounds.
    • Custom Bounds: Click the drop-down button to choose Select Object, Draw Rectangle, or Custom Expression to set tile bounds.
      • Select Object: The program switches to the current map. Click an object as the tile processing range. To select multiple objects, hold the Shift key and select objects sequentially. After selection, right-click to end the selection state and return to the Generate Map Tiles dialog.
      • Draw Rectangle: The program switches to the current map. Use the mouse to draw a rectangular range in the window. After drawing, right-click to end the selection state and return to the Generate Map Tiles dialog.
      • Custom Expression: The program will pop up the SQL Expression dialog, supporting setting tile bounds via SQL expression. The minimum bounds of the search results from the expression become the tile bounds.
      • Copy, Paste: The program provides Copy and Paste buttons to copy geographic ranges. Click the Paste button at a range setting that supports pasting to set the copied bounds' left, bottom, right, and top values to the current range.
  8. Filter Selected Object Layer: When tile bounds are set to the custom range method Select Object, check this item. The program will automatically filter this object layer when generating tiles; otherwise, no filtering is performed. This function is only effective when there are multiple layers in the map.
  9. Origin of Tile: The basis for map tile segmentation rules. When the origin of tile is determined, the tile segmentation rules are fixed. Map tiles with the same origin of tile can be merged. Vector tiles do not support modifying index bounds. For maps with a geographic coordinate system, the index bounds are always [-180, 90]; for maps with a projected coordinate system, the index bounds are always the top-left corner of the map bounds.
  10. After setting the above parameters, you can execute the map tiling operation.
    Notes:
    • Maps with a planar coordinate system do not support generating vector tiles. If the map has a non-planar coordinate system but a layer's corresponding dataset has a planar coordinate system, you need to change the dataset's coordinate system to a non-planar one.
    • Vector tiles do not support update/append tiles or resume/restore tiles.
    • Multi-point data layers do not support generating vector tiles. If multi-point data layers exist in the map, they must be removed before generating vector tiles.
  11. After completing the map cache task, the output window will prompt that the map has successfully generated planar map tiles. In the export directory, the following folders and files will be generated:
    • fonts: Font files used by vector tiles.
    • sprites: Style-related icon resources for vector tiles.
    • styles: Style description files for vector tiles.
    • thumbnail: Used to store thumbnails for vector tiles.
    • tiles: Vector tile data. When the storage format is Original, the generated tile format is *.mvt files; when the storage format is Compact, the generated tile format is *.cf files.

      In the tiles folder, tiles are stored in subfolders by scale level, with folder names as global levels, counting from 0. Subfolders under level folders are named by global column numbers, and file names are global row numbers.

    • sci File: The metadata description file for vector tiles, recording information such as data projection, geographic range, level scales, etc.
      Figure: Vector Tile Directory Structure

Related Topics

Map Tiles

Generate Vector Tile Styles

Vector Tile Cartography Notes

Map Tile Production FAQ