On Tuesday 17 October 2017, Kevin Kenny wrote: > It's impossible to base a rendering decision on something that isn't > represented by any tag.
That is not true, you can produce a lot of information through analysis of the data and by connecting it to data outside of OSM (which is usually outside of OSM because it is outside the scope of OSM). Most obvious example is label placement. If and where there is space to place a label for a certain feature is not represented by a tag. According to you it would therefore be impossible to render labels without overlap. But renderers do this by analyzing the data and selecting label positions based on that. Or the fact that highway=traffic_signals does not usually have a direction tag because if you want directed rendering of traffic signals in a map you can determine the direction by analyzing the data and determining the direction of the intersecting roads. The OSM database is not a rendering database, it does not try to contain everything you need to render a map in the form that is most convenient for rendering. It is a generic geo-database for information about the world that can be verifiably observed on the ground and that is useful for map rendering or other applications. > 'Tagging for the renderer' is telling a lie > to make something look good, not entering a fact into the > database so that some rendering can make use of it. If you newly introduce a tag that can never be 'Tagging for the renderer' in that sense because use of a newly introduced tag is never wrong in the sense it contradicts established use. I recently coined the term 'Preemptive tagging for the renderer' (http://blog.imagico.de/social-engineering-in-openstreetmap/) for this kind of tag which is being created because the inventor considers it useful for map rendering although it is either not verifiable or it is not a good way to represent a verifiable observation (like the famous is_in). -- Christoph Hormann http://www.imagico.de/ _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
