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Clip a polygonz feature

  • April 14, 2014
  • 9 replies
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I have a flat roof as polygonz feature that has dormer windows (I hope this is the correct expression) as additional polygonz hovering over it.

 

For drainage calculations I would like to have the flat roof polygonz with holes where the dormer windows are and additionally the dormer window as they already exist.

 

I tried to make a sketch of what I mean:

 

 

resulting Area A = A - ( B+C+D)

 

Total roof Area = Area A (with holes) + B + C + D.

 

 

AreaOnArea overlayer gives me weird looking results with a lot of artifacts. I tried to 2Dforce the roof and clip it like that but then I am unable to make it 3D again since there is no attribute I can use for it (because then I would merge the unclipped Area A again).

 

 

Thanks for your help!

Best answer by takashi

If the window intersects with boundary of the roof, it cannot be a donut hole. How about the Clipper and SurfaceDreaper?

 

 

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9 replies

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  • simon11
  • Author
  • April 14, 2014
Unfortunately there is no editing function here... In short, I want to penetrate Area A by Areas B,C,D or generally, penetrate Areas by Areas that lay above them.
gio
Contributor
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  • gioContributor
  • Contributor
  • April 14, 2014
Hi Simon,

 

 

 

This operation u want to do is basically a projection of the windows on the roof.

 

The roof is flat. Therefore u can remove the z values of all the objects and clip them.

 

then u can replace the z values of the (flat) clipped roof, with the original z value (wich makes it 3D again).

 

 

U wil be clipping the projected profiles of the windows of course.

 

 

 

Gio
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  • simon11
  • Author
  • April 14, 2014
Hi Gio

 

Thanks for your advise! Unfortunately I just realized that there are all kinds of roofs involved and not only flat ones... So I think I still project all the features to the ground, but how do I get them to 3D again.

 

Meanwhile I tried out the geometry reader but I am only able to restore the original shape and not the 2D clipped one (logically, because i read it in 3D).

 

Thanks for further help!
takashi
Celebrity
  • takashiCelebrity
  • April 14, 2014
Hi Simon, the SurfaceDraper (Group By: ID of Roof) might work.

 

 

Takashi
Why not inspect features with Visual/Data Preview and Feature/Record Information before writing them into a destination dataset?
takashi
Celebrity
  • takashiCelebrity
  • April 14, 2014
This seems to be better.

 

 

Why not inspect features with Visual/Data Preview and Feature/Record Information before writing them into a destination dataset?
S
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  • simon11
  • Author
  • April 15, 2014
Thank you very much Takashi, I think you led my on the very right track! However I still get some weird results concerning gabled roofs and also at some flat roofs. Do you have any idea why this could be?

 

before SurfaceDraper (green = roof, red = "window"):

 

 

 

after SurfaceDraper (draped features:

 

 

 

another error after DonutBuilder (the area in upper left corner should be "flat" without artifact area connected to the areas on the right):

 

 

 

Thank you for your inputs!
S
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  • simon11
  • Author
  • April 15, 2014
I did some other tests where I extruded my windows with a negative amount and then tried to clip the roof polygons with these solids. Unfortunately it does not seem to work. Is it even possible somehow?
takashi
Celebrity
  • takashiCelebrity
  • Best Answer
  • April 15, 2014
If the window intersects with boundary of the roof, it cannot be a donut hole. How about the Clipper and SurfaceDreaper?

 

 

Why not inspect features with Visual/Data Preview and Feature/Record Information before writing them into a destination dataset?
S
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  • simon11
  • Author
  • April 22, 2014
This is it! Thank you very much, Takashi.

 

 

Kind regards. Simon

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