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I have downloaded the dataset for the Areas of Outstanding Natural Beauty (England) from various places but some of the areas (at least 5 including Shropshire Hills, Devon, Cotswolds) do not appear in Google Earth Pro. The polygons are listed and GE will zoom to the relevant polygon but is not visible.

Data can be found at: https://data.gov.uk/dataset/areas-of-outstanding-natural-beauty-england3/resource/23d670a5-9c42-4cca-a2db-1c1d910d4b8f

Incidently when I proceed to fill the layer it also fails to work on other polygons - (e.g. Quantock Hills, Chilterns)

  • That's a really big KML file (over 70 MB), and it contains some very complex polygons, with way more vertices than are needed for most applications (eg: Cornwall has 688,948 vertices). That's probably what's making it hard for Earth to render the largest ones, and to fill the rest. What's your end goal for this file? If we know how you want to use it, we might be able to suggest a simplification technique that makes it easier to render, while supporting your use-case. – Christiaan Adams Sep 5 '17 at 16:32
  • Thanks @ChristiaanAdams - I use for surveying but more on a regional scale and rarely at minute local level, maybe by a agricultural field scale, i.e which field is in /which out of AONB, so within 50-100m accuracy. I've not had an issue with file size previously but as you say probably the amount of vertices. Even if I could separate the polygons and open each as required or simplify the vertices would be a great help. I can use QGIS. – SNA user1969 Sep 5 '17 at 23:08
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    Great, if you use QGIS, then you can use the Vector menu > Geometry Tools > Simplify Geometry. You can run that on the whole shapefile (all polygons) at once. The trick is picking the right Tolerance value, which depends on the units the dataset is in (Decimal Degrees is very different from meters). I usually play around with orders of magnitude until I find something that works... reduces the size of my polygons without distorting the shape too much, or loosing any of the small ones. – Christiaan Adams Sep 6 '17 at 7:07
  • @ChristiaanAdams - This worked very well for my use-case. Have simplified to a tolerance of 0.0001 which creates a much lower 3.5MB file. This polygons are only around 10 metres out at worse case but is an excellent guide for preliminary surveying. Much appreciated! – SNA user1969 Sep 6 '17 at 11:25
  • Great, I'll put this in an Answer for you. Good luck. – Christiaan Adams Sep 7 '17 at 7:37
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Looks like the issue is that this dataset contains some very large polygons with huge numbers of vertices.

One way to address this is to simplify the geometries to reduce the number of vertices in each polygon. This can be done with the free QGIS, using the Vector menu > Geometry Tools > Simplify Geometry. You'll need to choose an appropriate tolerance value, which will depend on the units that your dataset is in (eg: decimal degrees will be very different from meters). I usually experiment with tolerance numbers, going up and down orders of magnitude until I narrow in on a value that reduces the complexity of the polygons enough without distorting the shapes too much or loosing too many of the small ones.

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