Hello, If this isn't the proper mailing list to post this question, I apologize in advance.
I'm currently working with a group of individuals from the Cascadia Users of Geospatial Open Source (CUGOS) OS-Geo Chapter on creating our own OSM planet server. We currently have the planet file imported and updating, and are performing basic rendering using mod_tile + renderd with mapnik2. I'm experiencing some strange behavior in regards to rendering tiles at low zoom-levels (e.g. Zoom Level 4). Specifically, it appears that a number of layers are being rendered at these small-scales which should actually not be rendered based on the 'MaxScaleDenominator' values in my mapnik2 stylesheet. As all these layers are being rendered across such a large spatial extent, render times are extremely long. Utilizing Dane Springmeyer's nik2img.py [1] utility in combination with the osm.xml stylesheet [2] (our version is upgraded for mapnik2 syntax), I've produced the following log file [3]. AFAIK, a number of these layers should not be rendering (reported as visible) at zoom-scale 4. For example, the reported MapScaleDenominator via the nik2img log is, '22363290.3714'. With this in mind, I went ahead and searched my osm stylesheet for the 'MaxScaleDenominator' for one of the layers I assumed should not be rendering at zoom-scale 4, 'piers-area'. The following snippet shows that the MaxScaleDenominator parameter has a value much lower then the the reported MapScaleDenominator at zoom-scale 4. <Style name="piers-area"> <Rule> <MaxScaleDenominator>200000</MaxScaleDenominator> <PolygonSymbolizer fill="#f2efe9"/></Rule> </Style> Additionally, this same behavior is occurring using a different stylesheet, the osm-bright style by AJ Ashton of Development Seed. The nik2img logfile for the same location and zoom can be found here [4]. So... after all that, my questions are essentially: * Is it correct in assuming that all these layers should _not_ be listed as visible when rendering an image via nik2img at such a low zoom-level? * If so, what might be causing the disconnect between the layers that nik2img is reporting as visible for this mapscale versus the layers' own MaxScaleDenominator values in my stylesheets? Could it be a projection issue? Maybe something I'm introducing during the use of upgrade_map_xml.py to convert mapnik -> mapnik2 syntax? Thanks for any advice. I'd be happy to provide any further supplementary/clarifying info. -Matt [1]: http://code.google.com/p/mapnik-utils/wiki/Nik2Img [2]: http://svn.openstreetmap.org/applications/rendering/mapnik [3]: http://pastebin.com/QDQ701nZ [4]: http://pastebin.com/6HMpMvWb -- m a t t h e w k e n n y http://www.mkgeomatics.com _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev