OJ W schrieb:
* osmarender projection isn't quite right (when you render an image, it treats dLat/dy as constant when it should be more compllicated than that), and the smaller the area you render in one go, the less error you get. with 10km tiles the error isn't particularly noticable (someone post stats here - I'm sure we've run some on error % versus tile level). note: this was the case when [EMAIL PROTECTED] was first designed - osmarender may have improved since, and the perl version could certainly solve this
The midpoint of a 256px tile is less than 0.05 pixels off at z12 at 85°N/S, and about 0.0015 px off at z17. (this depends on the actual latitude of the tile, and the error gets less near the equator), so TilesPipe would have worked, only to fail at the same point where tilesAtHome now fails, i.e. the Tiles getting too complex to actually make use of this fact.
The smalles Zoom where the error is less than half a pixel at all times is z9. So this is where stitching should begin at the latest for lowzoom, as the error pretty much doubles for every zoom from here on towards z1.
* the larger the complexity of the region, the more work that therendering engine has to do.
again, ask on this list if you have any more specific questions
-- Dirk-Lüder "Deelkar" Kreie Bremen - 53.0952°N 8.8652°E
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