On 10 sep, 16:17, Anthony <[email protected]> wrote: > The WMS service says it supports EPSG:900913 (old Google Spheric > Mercator). Wouldn't it be better to use this -- with the corresponding > coordinate conversions for the bbox -- than sticking to EPSG:4326? > > Also, if you set the WMS parameter "transparent=true", you can use > these layers as overlays to the Google base layers. >
Anthony, adding transparency to Toporama layer just create black spots on the map. The better approach is to use the undocumented fonctionnality of using road transpartent layer of the Google G_HYBRID_MAP. This as for consequence that the text on the Road layer overlaps text on the Toporama layer. Also, we sometimes experienced problem obtaining tiles from Toporama. For theses reasons, I prefer to not use this fonctionnality. You suggest to use Google Spheric Mercator. I am not a GIS expert, but as I understand it, you work in a complete new approach. The page http://docs.openlayers.org/library/spherical_mercator.html presents the Spheric mercator projection. It says : Any time you see the string “EPSG:4326”, you can assume it describes latitude/longitude coordinates. Any time you see the string “EPSG: 900913”, it will be describing coordinates in meters in x/y. The programming examples I see in general refers to EPSG:4326. I wonder if functions written for EPSG:4326 can be used for EPSG:900913 whitout any adaptation. When overlapping Google road tiles over Toporama tiles, I see that roads fit very well. The problem might be different up north, bu in general, do we really have problems. I dont see what we would gain to use EPSG:900913 projection. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-maps-api?hl=en -~----------~----~----~----~------~----~------~--~---
