About Tile Generator Parameters

This topic provides additional information about the Tile Generator and WMTS Tile Generator parameters.

Tile Matrices (-matrixIDs)

The -matrixIDs parameter specifies the matrices to generate tiles for. This is a comma-separated list (such as 1,2,6) or a value range (such as 4-10). You would skip a matrixID in the list if it is already generated. When not specified, generates tiles for all supported tile matrices.

Setting the matrixIDs parameter to a value greater than 14 could create a large request file (for example, setting this parameter to "1-15"). We recommend generating separate request files in this situation. For example, generating a request file with matrixIDs set to "1-13" and then generating another request file with matrixIDs set to "14,15".

Minimum Bounding Rectangle (-mbr)

The -mbr parameter represents the Minimum Bounding Rectangle (MBR) to intersect the map with, which defines the list of tiles to generate. It has four values representing the lower left and upper right corners of a bounding rectangle in the coordinate system of the named tile. For example, mbr="-8275553, 4932706, -8188786, 5003330".

Using a smaller MBR generates fewer tiles for a target area.

If the MBR is outside the bounds of the tile definition, then an "Exception in thread ... doesn't lie within the grid bounds Rectangle" message displays.

To determine the MBR for your data, review the tile information in Spectrum Spatial Manager. For example, to determine the MBR for a sample data tile:
  1. Open Spectrum Spatial Manager and click Data on the menu.
  2. Expand the Root tree, expand Samples, and then click NamedTiles.
  3. On the Settings tab is information about the Bounds of the tile: Min X (longitude), Max X (longitude), Min Y (latitude), Max Y (latitude).

Tile Caching (-cache)

Use the -cache parameter when working with a third-party cache tool that requires a cache header. For example, set to false (-cache=false) to set the HTTP “cache-control” header to “no-cache” for a tile request. This tells the proxy server to go back to the originating server for the tile. The proxy server replaces what is in its cache with the new tile. Refer to the third-party help for how to set this property (how to set a cache header).

To have Spectrum Technology Platform create cache headers, you must turn cache.control.headers.enabled to true as described under Exposing Cache Control Headers for Map Display and then set the -cache parameter to true when generating tiles. Headers must have date and time information. See also, Exposing Cache Control Headers for Map Display.

If using Spectrum Technology Platform tile caching on the file system, then headers are not used until there is a tile request. For details about how to set caching for tiles in the Spectrum Technology Platform, see Managing Repository Cache in the Spectrum JMX Console.

  • WMTS Service: By default WMTS service caching is turned off. You can turn it on in Spectrum Spatial Manager for a specific map. For details, see WMTS Tile Cache.
  • MapTiling Service: By default MapTiling service caching is turned off. You can turn it on in the tile service configuration file, see Managing Map Tiling Resources and Configuration.
Note: A third-party caching tool may be more efficient at retrieving and storing tiles than Spectrum Technology Platform. The third-party caching tool asks Spectrum Technology Platform for tiles and then stores (caches) them and an application, such as Spectrum Spatial Analyst, retrieves the tiles from the third-party caching tool. To work with a third-party caching tool, you must turn the Spectrum Technology Platform cache off (set to false). For details, see WMTS Tile Cache and Managing Map Tiling Resources and Configuration.

You can set the expiration information for named tiles in Spectrum Spatial Manager, see Creating a Named Tile.

See also:

Output Directory (-dirOutput)

The -dirOutput is a legacy parameter that saves output tiles to a local directory on the machine running the tile generator.

Note:
  • If Spectrum Technology Platform tile caching is on (true), we recommend that you not use -dirOutput becasue Spectrum Spatial saves all tile images to the cache folder set by the administrator (admin) in Spectrum Spatial Manager.
  • If Spectrum Technology Platform tile caching is off (false) when using -dirOutput, then tiles save to the folder specificed on the machine running the tile generator.

To turn Spectrum Technology Platform tile caching on for the tile services:

  • WMTS Service: By default WMTS service caching is turned off. You can turn it on in Spectrum Spatial Manager for a specific map. For details, see WMTS Tile Cache.
  • MapTiling Service: By default MapTiling service caching is turned off. You can turn it on in the tile service configuration file, see Managing Map Tiling Resources and Configuration.