Hi Roland,
I'll have a think... but in general Smoother transformers keep all the
existing points and just re-arrange them into a nicer position. The
generalizer is the one that will remove points. LineGeneralizer
appears to give you more options than AreaGeneralizer; the Deveau
algorithm looking the better one to try (the help states it removes
points that don't add to the overall shape). Having said that it
appears to be more useful for removing spikes than point thinning.

If you're determined to create your own cleaner then my lateral
thinking is...

1) Drop the feature into points (Chopper)
2) Calculate the angle at each point
3) If the angle is 180 degrees (+/- a degree or two) then you know it
is a mid-line coordinate and you can ignore it (Tester)
4) Rebuild the feature from remaining points (PointConnector)

Dmitri's PolylineAnalyzer transformer on fmepedia should help to
calculate angles and bearings making the job way simpler.

http://www.fmepedia.com/index.php/PolylineAnalyzer

Hope this helps

Mark

Mark Ireland, Senior Product Specialist
Safe Software Inc. Surrey, BC, CANADA
[EMAIL PROTECTED] http://www.safe.com
Solutions for Spatial Data Translation, Distribution and Access

--- In [email protected], "Roland Martin" <[EMAIL PROTECTED]> wrote:
>
> Hi everyone,
> 
> This is a bit of a tricky one...
> 
> I need to convert some buildings (9-10 vertices apiece) to perfect
> rectangles (in FME terms, 5 vertices), with 90 degree (or as near as
makes
> no odds) corners. I will then need to extract the vertices, but that
I can
> do... Any ideas?
> 
> Unfortunately all the corners on the buildings are pretty much 90
degrees,
> so all the simplifying procedures seem to be fairly indiscriminate about
> which vertices to remove. I'm not overly familiar with what the
different
> tools (AreaGeneralizer; AreaSmoother; etc.) do, and what affect the
specific
> settings have, so I may have missed something here...
> 
> Alternatively I'm going down the traditional FME "lateral thinking"
route,
> and contemplating the following:
> - Run house through CentreLineReplacer
> - Duplicate centreline, and rotate by 180 degrees or some such
> 
> Trouble is, if the building isn't exactly square I don't think this will
> work.
> 
> Or... maybe do something with a BoundingBoxReplacer? Except they
don't all
> face North!
> 
> The obvious question is where the rectangle should fall - fully
inside the
> building; fully outside; or somewhere inbetween? Probably ideally
somewhere
> inbetween... Most of the buildings have three straight edges and one
with
> indentations, but some of them are more complex shapes.
> 
> Maybe I should pack it all in, and digitise them instead!!!
> 
> Does anyone have any bright ideas? Any help would be gratefully
received!
> 
> Cheers,
> Roland.
>




For insights into what's up at Safe Software and what's on the development 
horizon, visit Safe's blog at spatial-etl.blogspot.com.

Safe Software has also made slides available that outline enhancements planned 
for FME 2007. The slides are from the "Road Ahead" presentation given on Day 2 
of the FME Worldwide Users Conference. To view these slides, visit 
www.safe.com/2006uc.

 
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