I am very new to GIS, and my task is to overlay about 100 polygons on a map. I'm using Google Maps Javascript API v3.

I think I can define all my polygons as sets of lat/long coordinates in my database and programmatically loop through those sets of coordinates to create polygon overlays to put on the map.

Or, it looks like I can take an existing ESRI/ArcGIS shapefile and convert it to KML and use that for a custom overlay. This seems more difficult to me and like it may be problematic if I need to tweak my polygon data if I don't like what's in the shapefile. But I have no expertise with this, so I'm not sure.

At any rate, I don't know the advantages or disadvantages of either approach. Or if there's another approach I should consider.

Any guidance or words of wisdom are greatly appreciated.

  • 1
    Does your polygon data have attributes?
    – R.K.
    Nov 8, 2012 at 4:04
  • 2
    Good point, R.K. I hadn't considered anything beyond just the basic polygon boundaries, but I think you and sgrieve have convinced me to use the shape file and modify it to meet my needs, rather than reinvent the wheel by trying to recreate everything (and re-invent the wheel) in my database.
    – theog
    Nov 8, 2012 at 20:41

1 Answer 1


I recently performed a similar task, where I converted a series of 3D polygon shapefiles into KML files to view the data in Google Earth. I came across the Export to KML extension for ArcMap 9.3 or 10, which handles the export of shapefiles as KML, allowing labels, styles, temporal data and attributes to all be set and modified. I have found this extension to be much more powerful and user friendly than the standard ESRI tools for exporting KML data.

Another option I considered, but eventually rejected due to the need to use polygon styles defined in an existing mxd file, was to use FME to create a workbench to translate shapefiles into KML data. This would be an ideal solution if you will need to perform the same operations on a lot of shapefiles automatically, as the Export to KML extension cannot be scripted.

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