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I am having issues displaying points from KMZ files accurately at small scales when the map is zoomed out (e.g. zoom: 5).

Some of the points from the Farmers Markets KMZ layer for example start out in the water and then as you zoom in the points moves onto land and becomes more accurate as you zoom into the map. The points are only displayed in their accurate positions when zoomed in closely at a certain extent.

How can the points be displayed more accurately at small scale when the map is zoomed out? Thanks!

user1451316
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1 Answers1

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I've seen similar behavior in regular API markers when a custom icon is placed, that the marker appears to be "bumped" off to a side when zooming out. This effect has to do with where the marker image is anchored. By default, it looks like the KML markers are anchored at the center bottom of the image.

Notice that the farmers' market PNG image below has a lot of blank "padding". Since the anchor to the map is at the bottom of the image, when zooming out, the red dot will appear to move north.

marker image

I found a page saying icons need to be at least 32x32 so the padding should stay there.

To change the anchoring location, add the <hotspot> option to the IconStyle, as described here, for example, to the center of the image:

<hotSpot x="0.5" y="0.5" xunits="fraction" yunits="fraction">

Heitor Chang
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  • So I've cropped the png and added in the hotspot code in the kml file within the kmz and the points are still showing up in the water..any ideas? I created the kmzs from shapefiles so was there a specific projection I needed to project the shapefiles before I convert them? – user1451316 Jun 14 '12 at 14:39
  • I checked the site again and did some more research. First, Google maps caches the kml and one way of refreshing the kml is adding bogus parameters like `?random=123` at the end of the url [(source here)](https://groups.google.com/forum/?fromgroups#!topic/Google-Maps-API/12MpMvkS5a4) When I did that I saw that all the icons were scaled to 3 or 4 times their size, which is no good. Only then I found a page saying the kml icons are supposed to be a minimum of 32x32, so cropping was a bad suggestion, I apologize. I think keeping the original 32x32 icon but using `hotSpot` will work. – Heitor Chang Jun 14 '12 at 16:31