Key:shade
 shade
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| Description |
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Indicates whether a feature is in shade. 
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| Group: properties |
| Used on these elements |
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| Status: in use |
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The key shade=* is intended to indicate the presence of shade. This article is to document actual usage of the tag and possible issues.
Current use
shade=* can be used on nodes, ways, areas or relations. Most often used on a way tagged with highway=* but sensible on many other ways, too.
Issues to bear in mind
Current use of this tag is focused on places that are shaded in most seasons and most times of day, e.g. because they are covered by vegetation, as in the photo.
Other use cases need to consider that shade changes over time depending on the position of the sun east-to-west during the day and above the horizon through the seasons. The position of the sun can be calculated (see e.g. http://suncalc.net/) and shade can be calculated from 3D mapping where available (see e.g. F4 Map). In the absence of 3D data, a place can still be described in terms of the directions from which it could be shaded at a given time of the year, indicating that there is an object of the right shape and height in that direction. No tagging scheme currently exists to capture this type of information.
As with lit=*, shade properties potentially vary at very fine spatial scale, but it is not typically appropriate to capture the full level of detail in Openstreetmap due to limits on precision of positions and angles. Mapped shade should be considered approximate. For example, small errors in directions and heights of distant objects can have a big influence on whether shade is actually observed. At the edge of shadows, small changes in length of shade over time may mean that shade is not observed. Shadows may also exist for only short periods of time, e.g. long shadows cast by short objects near sunrise and sunset. Shade should generally therefore be considered a property of existing objects rather than being explicitly mapped in detail.
Rendering
Shade is not currently rendered by any known style.
See also
Tags that imply shade:
Previous work on proposals:
Similar concepts:
- lit=* is similarly a property of a place relative to a light source, typically highway=street_lamp