Am 02.03.2011 14:03, schrieb Felix Hartmann:
On 02.03.2011 13:53, Marko Mäkelä wrote:
On Wed, Mar 02, 2011 at 01:45:52PM +0100, Minko wrote:
Negative consequence is that on Mapsource most of the forest disappears too soon, when zooming out. How hard would it be to merge nearby polygons on wider zoom levels? It would not work I think. What would be needed is to generalise polygons on lower zoom levels. Meaning merge them together, drop holes, straighten them (well the dp-filter already takes care of that), and have a seperate style-file where there are definitions on what gets merged how.
In general I think this should be solvable. It will be not an easy task and maybe resource hungry, but I think, this should be possible. The subject was discussed already in January 2010 in a side thread of 'Suggestion - Make Douglas Peucker Algorithm more Configurable'
Ideally a hole or scrub part of a forest would be only visible from resolution 24-22 or 24-21 (depending on the size of the whole/scrub). It's the same as you only want to see single houses when zoomed in close, when further away you want to see residential area, and when even further away you want to sea where is urban vs nonurban area. Yes, this would be nice. OSM sucks big in this regard and as long raster maps are the primary outcome of OSM data (for lower zooms) then there will be no motivation for change (change which means layering OSM data instead of one big black hole to sink information into).
OSM is not a perfect world for cartogaphs. But we have to take it as it is. And it is a database which shows a more or less detailes map at *one* zoom level, the nearest one. I wouldn't like it to include the same information in several zoom levels which have to be held consistent by the users. This will not work. This is a task which *must* be done by algorithms. Regards, Johann