Question

Buffer left/right only

  • 15 November 2013
  • 10 replies
  • 64 views
michael
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I'd like to buffer only one side of a line. According to the FMEpedia articles below, in FME 2012 and later the Bufferer transformer should have this as an option. I'm using FME 2013 sp4 (13547) and the transformer doesn't have it as an option. Am I missing something?

 

 

http://fmepedia.safe.com/articles/Samples_and_Demos/Buffer-On-Left-or-Right-Side-Only

 

http://fmepedia.safe.com/articles/FAQ/Whats-Great-2012

 

 

I did find the MultiBufferer from the FME Store but I can't get it to output a polygon, just a line that is offset the distance I wish the buffer to be.

 

 

Michael

10 replies

M
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Look up the custom transformer "MultiBufferer."  If you have FME 2012+ and you start typing it, the custom transformers will appear in the list on the canvas. 

 

 

If it's not already downloaded, it will connect to the FME store and download it (less than a second) and add it to your workbench.

 

 

Then you'll have the option of selecting left or right only, in addition to other options.
david_r
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Hi,

 

 

it might also be possible to accomplish something similar using the OffsetCurveGenerator before the Buffferer.

 

 

David
takashi
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Hi Michael,

 

 

This is an experimental workflow. If the line has self intersections, it doesn't work. A certain improvement will be required...

 

 

 

Takashi
takashi
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... the second SpatialFilter is not necessary. The first one outputs right side polygons to FAILED port. 
david_r
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Here is the "official" solution from Safe:

 

http://fmepedia.safe.com/articles/Samples_and_Demos/Buffer-On-Left-or-Right-Side-Only

 

 

Haven't compared it to the one by Takashi, though...

 

 

David
takashi
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Yeah, I remember old Bufferer indeed has options LEFT_SIDE_ONLY, RIGHT_SIDE_ONLY etc., but the current Bufferer (Version 11) doesn't have those options. Where have they gone???
david_r
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Indeed. It would be nice if someone from Safe could chime in on this matter :-)
G
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u can always offset the line to a half of the desired left/right buffer.

 

Then buffer the offsetted line with this same number.

 

 

Assuming the offsetter has a left/right choice left in FME2013...lol
takashi
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Userlevel 2
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Hi Gio,

 

 

No, the Offsetter of FME 2013 has not such options - left / right. But you can use the OffsetCurveGenerator transformer to perform your approach. Although a small gap between the original line and resultant polygon may occur at a bend of the line, if such a gap is allowable, I think your approach is very effective :-)

 

 

Takashi
R

Hello everyone,

 

I am using FME 2020.2 and I would like to do a single side buffer (as it exists on QGIS) with line. The line's width is in an attribute.

According the conversation and what I have read that option was possible in the old fme version. But on my version this option is still not available.

I have tried to read the official answer from Safe posted by Mickael and david_r but the articles don't seem still available.

The "MultiBufferer" doesn't work properly in my case. It creates only lines around the polygon like "OffsetCurveGenerator".

I have tried the method proposed by gio but I have angle, start and end effect.

Do you know if I have missed a better method to create that kind of polygone ?

 

Thank you for your help

 

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