Vector tiles , tiled vectors or vectiles [1] are packets of geographic data, packaged into pre-defined roughly-shaped shaped “tiles” for transfer over the web. This is an emerging method for delivering styled web maps , combining certain benefits of pre-rendered raster map tiles with vector map data. As with the widely used raster tiles web maps , map data is requested by a client as a set of “tiles”. Unlike raster tiled web maps, however, the server returns the data, which has been clipped to the boundaries of each tile, instead of a pre-rendered map image.

There are several major advantages of this hybrid approach. Compared to an un-tiled vector map, the data transfer is reduced, [2] . The GIS clipping operations can all be performed in advance, as the tile boundaries are pre-defined. GIS system is available to serve data.

Compared to a tiled raster map, data transfer is also greatly reduced, as vector data is typically much smaller than a rendered bitmap. Also, styling can be applied later in the process, or even in the browser itself, allowing much greater flexibility in how data is presented. It is also easy to provide interactivity with map features, as their vector representation already exists within the client. [2] Yet another source is the rasterization, which can be performed directly in the client. GPU [s] in everyone’s pocket “. [3]

History

There is a long history of the use of vector tiles in GIS. A very early GIS (circa 1966), the Canada Geographic Information System (CGIS), used a vector tile storage scheme. [4] CGIS used the term “frame” instead of vector tiles.

In 1975, the US Wildlife Service initiated a national program to map and digitize all the wetlands in the US. In 1976 they awarded a contract to an automated software application which allowed stereo imagery to be digitized using an analytical stereo plotter. Later support for 2d digitization from single photos (aka single photo resection) on a digitizing table was added. The software was called WAMS (Wetlands Analytical Mapping System). The WAMS data store used a tiled vector structure. Each tile was called a “geounit”. A geounit corresponds to one of the USGS quadrangle scales, typically 1: 24000. As the data were digitized, they were immediately stored in the tiled data store and topologically structured. Lines crossing geounit boundaries were automatically split. The Storage Coordinate Reference System (CRS) was WGS 72 lat / long.

Building on the operational experience gained in implementing and using the Map Overlay and Statistical System (MOSS), [5] in 1986. Later GenaMap). The vector tile structure and capability is described in “DeltaMap: Not just another GIS”. [6] Where WAMS is based on latitude / longitude 1: 24000 quadrangles, DeltaMap allowed to use any coordinate reference system (CRS). In this way, sparse data required a few tiles but dense data could use much smaller tiles. R-trees were used as the indexing scheme for the vector tiles. In the late 1980’s, Genasys further enhanced GenaMap to allow “Continuous, seamless” processing of the tiled layers. Basically, from the end user perspective, the tiles became invisible. This capability was true regardless of whether the user was editing, visualizing, querying, or analyzing the data.

Standards and approaches

As of early 2015, there is no dominant standard for vector tiles. Approaches can differ in their URL format, data serialization format, packaging of styling information, and support for projections other than Web Mercator.

Protocol buffers (Mapbox)

Tasks for the use of the ” protocol-buffer” for the use of the ” protocol-buffer” . Web Mercator is the projection of reference, but can be used to represent data with any projection and tile extent scheme. [7] It is also tied to the Mapnik rendering engine, using a “serialized version of the internal data that Mapnik uses”. [8]

In March 2015, Esri , the dominant geospatial software maker, announced that they would be supporting Maples’ standard tiles in both server and client platforms. [9]

Mapnik Vector Tile

This was an early format developed for the Mapnik renderer. [10]

Other formats

The approach followed by TileStache is to allow multiple data serialization formats; As of early 2015, it supports GeoJSON, ArcJSON, GeoBSON, Arc GeoServices BSON, GeoAMF and Arc GeoServices BSON. The requested format is given in the URL (eg, http://example.com/tiles/mylayer/2/1/3.json)

Support

Services and applications

Vector tiles-have-been used by the Google Maps Android client since December 2010 [11] and on the desktop customer since 2013. [12] Vector tiles for rendering OpenStreetMap data Were Proposed first in March 2013 [1] and are supported by Mapnik, [ 13] the most widely used renderer of OpenStreetMap data. Mapbox Studio, around vector tiles. [14]

The popular, and very powerful, Android client for OpenStreetMap data, osmAnd supports vector tiles, which it calls “vector maps”. [15]

Servers

The tile server pipeline TileStache supports several flavors of JSON natively. [16] There est aussi a plugin called Expired vector tile provider VecTiles [17] qui converts data into PostGIS vector Mapnik tiles in Vector Tile Format (incompatible with the MapBox specification [18] ) or TopoJSON .

PGRestAPI (also known as Chubbs Spatial Server) is a standalone NodeJS server that can also generate tiles on the fly from a PostGIS data source, as well as pre-generated vector from sources such as Mapbox Studio. [19]

ESRI ArcGIS Server 10.4 [20] and ArcGIS Pro 1.2 [21] released in February 2016 added support for vector tiles.

Client libraries

The Leaflet Leaflet 0.7.x [22] and Leaflet.VectorGrid for Leaflet 1.0.x. [23]

Mapbox’s own JavasScript library, Mapbox.js, can be used. [24]

OpenLayers supports tiles through the ol.source.TileVector object, [25] as of version 3.

External links

  • Vector tiles (OpenStreetMap wiki)
  • OpenMapTiles project

References

  1. ^ Jump up to:b “the liberty of postgreslessness: tiled vectors in mapnik (tecznotes)” . Mike.teczno.com . Retrieved 2014-08-24 .
  2. ^ Jump up to:b “About Tiled Vectors” . Research.microsoft.com . Retrieved 2014-08-24 .
  3. Jump up^ Migurski, Michal (2013-04-01). “Geomeetup Slides 2013-04” (PDF) .
  4. Jump up^ “Introductory Readings In Geographic Information Systems” . CRC Press . Retrieved 2016-04-26 .
  5. Jump up^ Moss: A Historical Perspectivehttps://www.scribd.com/document/4606038/2004-Article-by-Carl-Reed-MOSS-A-Historical-perspective
  6. Jump up^ Reed CN (1986) DELTAMAP: Not just another new GIS-Proceedings of the 3rd International Symposium on Spatial Data Handling. IGU Commission on Geographical Data Sensing and Processing, Williamsville NY, pp. 375-83
  7. Jump up^ “vector-tile-spec / 2.1 at master · mapbox / vector-tile-spec · GitHub” . Github.com . Retrieved 2016-05-24 .
  8. Jump up^ “Vector Tiles Overview” . MapBox.
  9. Jump up^ “Mapbox Vector Tile Specification adopted by Esri” . Mapbox blog . 2015-03-17.
  10. Jump up^ “Python: module TileStache.Goodies.VecTiles.mvt” . Tilestache.org . Retrieved 2015-11-20 .
  11. Jump up^ “Under the hood of Google Maps 5.0 for Android – Official Google Mobile Blog” . Googlemobile.blogspot.com.au . Retrieved 2014-08-24 .
  12. Jump up^ “Redesigned Google Maps hands-on: vector-based, more personal and coming soon to mobile” . Engadget.com . Retrieved 2014-08-24 .
  13. Jump up^ “mapbox / mapnik-vector-tile · GitHub” . Github.com . Retrieved 2014-08-24 .
  14. Jump up^ “Vector Tiles for MapBox Streets | Mapbox” . Mapbox.com . Retrieved 2014-08-24 .
  15. Jump up^ “HowToVectorTileData – osmand – This article describes how to use key features – Global Mobile Map Viewing & Navigation for Offline and Online OSM Maps – Google Project Hosting” . Code.google.com . Retrieved 2014-08-24 .
  16. Jump up^ “TileStache.Vector” .
  17. Jump up^ “TileStache.Goodies.VecTiles.server” .
  18. Jump up^ “Protobuf.skip unimplemented types · Issue # 15 · SpatialServer / Leaflet.MapboxVectorTile” . GitHub . Retrieved 2015-11-20 .
  19. Jump up^ “PGRestAPI (aka Chubbs Spatial Server)” . 2015-02-25.
  20. Jump up^ https://blogs.esri.com/esri/arcgis/2016/02/18/arcgis-10-4-is-here/
  21. Jump up^ https://pro.arcgis.com/en/pro-app/get-started/whats-new-in-arcgis-pro-1-2.htm
  22. Jump up^ “Leaflet.MapboxVectorTile” . GitHub . 2015-02-12.
  23. Jump up^ “Leaflet.VectorGrid” . GitHub . 2017-02-16.
  24. Jump up^ “API Documentation” . MapBox.
  25. Jump up^ “Open Layers 3 documentation” .

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