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Making a polygon fill than mimics a random but patterned geometry of rice paddy fields

January 14 2009 | 1 comment
Categories: Symbology

Hello there,

I am wondering if there is a nice way that someone already knows or can deduce how to develop a polygon fill that would mimic (randomly) the layout of typical rice fields.

Essentially I would like to give the impression of rice field in a land use layer where one of the classes in "rice paddy land".

Even better than this would be to develop a raster. I have been working on "bump mapping" techniques as described by Nighbert and would like to convey agricultural land as a land use class and add such a texture to a DEM thus giving a "Cartographic Realism" to the map. However fields in North America and Europe are quite different than in Asia. In America or Europe rows of straight lines or uniform boxes might give the impression of agri-land. In Asia they seem to be more irregularly placed.

If there could possibly be a raster calculator excpression I could build to create such a surface that would be exceptional.

The following links are examples of rice paddy and the attached picture from Google illustrates what I mean perfectly.

www.goviya.com/sansoni/birds-eye-view.htm
http://www.ij-healthgeographics.com/content/6/1/21/figure/F3
http://www.ij-healthgeographics.com/content/6/1/21/figure/F4

Hope you can help.

Mapping Center Answer:

The very best way to do this is using a picture fill symbol. But the picture you use for the symbol has to be created so it will tile in such a way that you will not see the edge effects. There are a number of good examples of picture fill symbols that tile well in the Geology24K style – check out Tailings and Quartzite to see what I mean. I will also put some pictures that we created for rice paddies on the ArcGIS Resources -> Styles page of Mapping Center tomorrow.  You will need to copy the picture files into the picture folder on your desktop, or you can navigate to them on an individual case when you reference them in the picture fill symbol.

There is also a Rice picture fill symbol in the Forestry style, but it is not like the one you want – it has shoots of rice, not fields of rice.

One thing you could try if you don't want to make your own picture fill symbol symbol is to use one of the images you have already as the picture in the picture fill symbol. You will need to convert it to .bmp format first. If your polygons are too big, the picture will tile and you will see the edge effects. So this often doesn't work very well.

Also, You might try posting your question to CartoTalk – perhaps a cartographer has already created a picture that can be used in a picture fill symbol.

Great Advice! posted by Alan Boatman on Jan 15 2009 7:20PM
Great advice. I think the best solution for me might be to open the picture I have from google in Adobe Photoshop. Then manipulate the colours and simplify them (making a better contrast) and then saving the file as a bitmap. Then I can use it as you suggest in a picture fill. The trick will probably be in insuring smooth tiling as you say. I will have a play.
My gut feeling (although I don't understand the maths) is that the raster calculator probably can't create such an effect for use on a DEM. The effects created by Nighbert, Buckley and Barnes are quite amazing though, I never thought you could do such things with a raster.

Thanks so much for your help. I will post how I get on in a couple of days and share it if the results are satisfactory.

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