Tile Properties
These properties can be set or modified for named tiles in Spectrum Spatial™ Manager.
Property | Description |
---|---|
Reference Resource | The named map, layer, or table that the tile references. Click to browse for a new one. |
Coordinate System | The coordinate system projection to host the named map. The Map Tiling Service will transform the named map into the projection defined. The projection is defined using the EPSG format. For best results, use epsg:3857 (Popular Visualization CRS or "Popular Mercator"). Click to browse for a new one. |
Bounds | The tile bounds define the full extent of the tiled map in units of the selected coordinate system. If you select Default Tile Bounds, appropriate default values are populated automatically for some coordinate systems such as WGS84, British National Grid, and Popular Visualization CRS; override these with custom bounds only if necessary. For all other coordinate systems, select Custom Tile Bounds to specify custom values. |
Image Formats and Vector Formats | The formats in which tiles can be requested. These can be raster image types
(PNG, GIF, and JPG/JPEG), a vector type (MVT - Mapbox vector tile), or a combination
of both types. At least one format must be selected. For more information on vector
formats, see Vector Tiles. Note: If image formats are selected, be aware that a named tile that references a
named table may be rendered without any styles. If only MVT tiles are used, a small
Pad Factor (for example, 0.02) will give better performance. |
Vector Settings | If you selected a vector format (MVT), then this section is available for you to choose which table columns or theme expressions to expose as attributes. Style, raster, and geometry attributes are not available for selection. |
Advanced Settings | |
Tile Levels | The minimum and maximum zoom levels to host the map. Values range from 1 to 25. The level shows how close the map image is to the Earth. Level 1 is the furthest away and is composed of one tile that the entire map will be drawn into. For more information, see What Is Tile Level?. |
Tile Expiration | Optionally choose the date (Expire on a date) or age in time units you
designate (Expire at age) of the tile after which the HTTP client should replace the
map tile in its cache with a new copy that it requests from the server. Otherwise,
by default a tile never expires; that is, the HTTP client will continue to request
the same tile from the server and it will not be refreshed in its cache. This field
displays either a date (YYYY-MM-DD) or a time value in days. For more information on HTTP client caching, see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html . |
Tile Width | Width of a tile in pixels. Must be greater than or equal to 16. |
Pad Factor | Used to prevent the clipping of labels when a label crosses a tile boundary. Controls the number of tiles that are rendered around the requested tile, with 0 meaning no padding, 1 meaning padding of 1 tile around the requested tile. If a preference is not specified, the global preference in the configuration will be used. If neither is specified, the default is 1.0. More padding results in less label or symbol clipping, however performance is negatively affected by large pad factors. |
Image Settings | These settings (Background Opacity and Render Labels) are relevant only to image formats (PNG, GIF, or JPG/JPEG) and not vector formats (MVT). |
Background Opacity | The level of background opacity (transparency) for the tile images displayed as
a percent, where 0% is completely transparent and 100% is completely opaque. When setting background opacity, you should keep in my mind how your basemap appears when overlaid with labels or symbols to ensure there is enough contrast. |
Render Labels | Choose to render existing label layers on the map when generating a tile. If a preference is not specified, the global preference in the configuration will be used. If neither is specified, the default is Yes. |