I am doing a project for an organization using OL. I was successful in creating buffers around a point for a given radius, but I was just shocked from their response,they just asked me is there a chance to create a amoeba shaped(no definite shape) object(just like circle,polygon) and project it on the map. I was stunned and couldn't even reply them 'NO'; As far as I know its impossible to create a amoeba shape.

If at all if there is a chance to create a shape like that then what are the requirements to be known?? like radius for a circle, number of sides with angle for a polygon etc........

Is it possible to create such a shape???

  • If you can get the points co-ordinates for polygon, then it is fine.. That is all needed
    – Senthil
    Apr 15, 2011 at 21:08
  • 5
    Just georeference an image!
    – whuber
    Apr 15, 2011 at 21:15
  • or use an image as the point symbol with variable rotations
    – Brad Nesom
    Apr 15, 2011 at 21:20

3 Answers 3


Maybe generate random points within an envelope, generate an alpha shaped polygon from the points, then remove the interior rings.

From Edelsbrunner's paper.

enter image description here

With the interior islands removed, these would look like amoebas to me.


If you have a steady hand you can draw amoeba shapes on the map with the Path Handler: http://dev.openlayers.org/docs/files/OpenLayers/Handler/Path-js.html

If you want to use code to generate "amoeba shapes" programatically, then the Path handler is not what you want.


I'm with whuber. Georeference an image to the approximate scale of your buffer and digitze the outline off of the image. This really shouldn't take very long. Is this purely for graphic reasons?

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