[OpenLayers-Users] MultiPolygons

[Scott Lewis]

Polygon objects have an exterior ring and (optionally) multiple interior 
rings.  With OpenLayers, when you create a Polygon object, the first 
Ring you provide is the exterior ring; the rest are the interior rings. 
  If you had multiple "holes", you could add them.

Seems like you found out how to get it to do what you want, but I 
figured it wouldn't hurt to know "why" it works!


A MultiPolygon would be used if you have multiple, independent polygons 
that you wanted grouped together; each polygon could have internal rings 
also, but each polygon would be a separate entity and wouldn't really 
affect the definition of the other polygons.  You are correct that for 
what you need, a MultiPolygon isn't needed.

Scott

Brad Spencer wrote:
> -->
> 
> Ok, found out that if you just force two LinearRing geometries into the 
> same polygon object you get two polygons that are fused together as it 
> were. No need to use MultiPolygon!
> 
>  
> 
> var parcel01= new OpenLayers.Geometry.LinearRing(pointList01);
> 
> var parcel02 = new OpenLayers.Geometry.LinearRing(pointList02);
> 
> var polygonFeature = new OpenLayers.Feature.Vector( new 
> OpenLayers.Geometry.Polygon([parcel01, parcel02]));
> 
>  
> 
> At least it does what I want.
> 
>  
> 
> Cheers,
> 
>  
> 
> Brad…
> 
>  
> 
> *From:* users-bounces at openlayers.org 
> [mailto:users-bounces at openlayers.org] *On Behalf Of *Brad Spencer
> *Sent:* Tuesday, October 27, 2009 5:52 PM
> *To:* openlayers users
> *Subject:* [OpenLayers-Users] MultiPolygons
> 
>  
> 
> List,
> 
>  
> 
> I cannot see any examples of this so thought someone may have done the 
> and can help me.
> 
>  
> 
> Its not clear how to make a multiPolygon vector object. I can create 
> individual polygons no problem but how for example would you generate 
> two concentric circles  as a single polygon with no lines joining the 
> two circles? This would be is the same as a donut shape.
> 
>  
> 
> Cheers,
> 
>  
> 
> *Brad Spencer*
> 
> NuMaps
> 
>  
> 
>  
> 
> 
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