[Talk-us] NHD Dataset

Ian Dees ian.dees at gmail.com
Mon Feb 16 18:55:51 GMT 2009


It looks like the solution is to use Advanced Multipolygons:

http://wiki.openstreetmap.org/wiki/Talk:Relation:multipolygon#Advanced_multipolygons

Does anyone want to start writing an algorithm to nicely slice up polygons
into "small enough" chunks?

On Mon, Feb 16, 2009 at 11:02 AM, Rev. Theodore Book <tbook at libero.it>wrote:

> I know that splitting large areas into smaller polygons makes some of the
> processing faster, but it seems to me that it introduces some problems, as
> well - by having multiple "lakes" with the same name, for example, it seems
> that it would be more difficult to render names properly, and the
> representation seems to become rather arbitrary.  Is there a proposal for a
> relation to identify that the multiple areas are actually parts of the same
> polygon?
>
>
> Christopher Schmidt wrote:
>
>> I don't think either is enough. In order for things to render correctly,
>> the standard way when tracing is to create smaller closed polygons --
>> the Charles River is a set of 10 or so, I believe.
>>
>> I don't know enough about water to know if other things will work, but I
>> do know that the 0.6 API switch will 'split' any way over 2000 nodes;
>> perhaps there is some documentation related to that talking about what
>> will be one or how to wavoid problems...
>>
>> Regards,
>>
>>
>
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