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I've installed OpenLayers in Drupal 7 and created a view that pulls geofield data for a "Geography" vocabulary (states, tribes, and U.S. jurisdictions) and shows points on a map that I'm storing on MapBox's server. The map tiles I created in TileMill.

The map displays fine, the points appear in the proper locations, but I can't get the map to center properly -- it appears somewhere off the coast of western Africa. I'm guessing that this is a "projection" problem.

  • TileMill maps are always projected to "Web Mercator" (EPSG:3857)
  • So, for the layer that I've added, I've used layer type "XYZ" and set the "Projection" to "EPSG:3857"
  • In the "Layers & Styles" tab for the map, I've selected "EPSG:3857" for the "Map Projection"
  • I've also set the "Display Projection" to "EPSG:3857"
  • Because I'd like the map to be centered over/near California, I've made the "Centerpoint" in the "Center & Bounds" tab equal to "-122, 33"
  • I've also tried "Zoom to Layer" in the "Behaviors" tab -- but that doesn't seem to work either.

I'm guessing there's something conceptual that I'm missing here -- that there's something about projections that I don't understand, right?

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    sounds like you have found Null Island nullisland.com - try specifing the center of your map in meters instead of degrees
    – Ian Turton
    Commented Mar 17, 2014 at 14:15
  • I tried MickyInTheSky's suggestion "-13268680,4332034" (which would be in meters, right?) but the map won't recenter.
    – beuner
    Commented Mar 17, 2014 at 16:01
  • @twogunz - Converting the coordinate pair used by you (-122 33 - EPSG: 4626) I realized that fall into the Pacific ocean (or as Iant said near "Null Island"). The coordinates "-13268680,4332034" (EPSG:3857) corresponds to a point about 20 km SE from Visalia (CA).
    – MickyInTheSky
    Commented Mar 18, 2014 at 7:55
  • I thought "Null Island" was off the coast of Africa? Still, when I use your converted (EPSG:3857) coordinate pair I still can't get the map to recenter properly. Ugh! Thank you for all your help, though! I'll have to try wildintellect's suggestion...
    – beuner
    Commented Mar 18, 2014 at 14:42

2 Answers 2

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Followup to Micklyn's response: After map intialization do a setCenter, you can also do a reproject on the coordinates to make it easier to read.

map.setCenter(OpenLayers.LonLat(-122,33).transform(
    new OpenLayers.Projection("EPSG:4326"),
        map.getProjectionObject()))

Example at line 138.

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If you want to use exactly this centerpoint, maybe you have to reproject the coordinate pair "-122,33" (are they in EPSG:4326?) in the EPSG:3857.

You'll get a pair of values ​​similar to "-13268680,4332034"

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  • Thanks -- I tried "-13268680,4332034" in the "Centerpoint" field for the map in the OpenLayers module, but to no avail.
    – beuner
    Commented Mar 17, 2014 at 15:59

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