Christopher Schmidt ha scritto: > On Thu, Nov 29, 2007 at 04:35:13PM +0100, David E. Reksten wrote: >> Hi, >> >> we're using GeoServer/TileCache/OpenLayers serving several datasets >> stepwise by scale. We've set the sld (using Min/Maxscaledenominator) >> to display a particular dataset from 1:1-50000 (meters), but it >> doesn't display before around 1:39000. >> >> Our dataset is stored as UTM32, and at first I thought the above to be >> related to this bug: http://trac.openlayers.org/ticket/958 >> But the error is still there after applying the patch manually. >> >> We used OpenLayers.Util.getResolutionFromScale(50000, 'm') to get the >> contant used in tilecache.cfg and in OpenLayers. > > /** > * Constant: DOTS_PER_INCH > * {Integer} 72 (A sensible default) > */ > OpenLayers.DOTS_PER_INCH = 72;
Hi Chris, about this scale inconsistency, you're right in saying it's due to the DPI. The WMS standard suggests a DPI of approximately 90 (well, a multiplication factor of 0.28 in fact), and that's what GeoServer is using to compute the scale. To be exactly true to the WMS standard (as far as I understand it) the setting would have to be: OpenLayers.DOTS_PER_INCH = 25.4 / 0.28; Wondering if OL should default to it too (or is MapServer defaulting to 75dpi instead?). Cheers Andrea _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
