[Tagging] Relation for saying "x is attached to y"?

Richard Welty rwelty at averillpark.net
Mon Aug 30 14:18:43 BST 2010


  On 8/30/10 9:06 AM, M∡rtin Koppenhoefer wrote:
> 2010/8/29 Pieren<pieren3 at gmail.com>:
>> On Sun, Aug 29, 2010 at 11:37 AM, Nathan Edgars II<neroute2 at gmail.com>
>> wrote:
>>> Perhaps a site relation? I'm not sure it's necessary; any application
>>> that needs that information can calculate whether the polygons
>>> overlap.
>>>
>> Yes, the topology shows what is "inside" or "outside" the polygon. And you
>> can use the tag "layer" to say what is on the top of what.
>
> +1, but site-relations might still be useful in the context of power
> generators. There are situations where the single objects do not
> overlap but are side a side, for example you might have 3 generators
> with 3 chimneys and want to model which chimney is connected to which
> generator.
i'd lean towards site relations being useful because i think that
the computational complexity of doing lots of polygon intersections
is being underestimated. yes, for small bounding boxes it's ok,
but consider if you needed to do it on a larger scale, it'd make
certain tasks completely unreasonable (i'm not sure what those
tasks might be yet, haven't thought about it.)

richard




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