Question

cleaning cad data by concentration of objects


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Dear FME users, 

 

 

I have a task to upload survey areas contours for different years from dwg into polygon shape format. And I am using FME for automatic transformation of data into gdb. Sometimes my .dwg contain unnecessary data and my idea is to leave only those parts of dwg that has the majority of objects in it (let's say it's ok if I neglect 10% of data as I need just outlines of survey areas). To be more clear, I attach a picture of original data in dwg and purple margin of what I want to receive as output. Any ideas how I can achieve that? I have a few thoughts, please share your views on that, thanks a lot in advance. kkt

 


5 replies

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My way of thinking was to somehow calculate concentration of objects in the drawing and drop all the parts with less than xxx% concentration. For that I may need a grid and  convert all obejcts into points first. After that I may use a hull builder to make an outline. Any other ideas, please? thanks a lot
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If you wan't to test for density of objects, you could use densifier/chopper to reduce objects to points with equilateral distances.

 

From points you can create a density map.

 

 

 

But i think you can satisfy your need with HullAcumulator and group by layer (or if yu dont have layer, expose colour and use that as a group by attribute)
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Hi Howard, Gio. Thanks for your answers. My issue is that I want to enable bulk processing. If you look at the picture I attached in the starting message, my outline (in purple) contained ALL layers (with different colors and properties) and the hull I want to get should be created not by layer or by color but by the area with the most concentration of the objects. 
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Hi, KKtshka

 

 

In that case i would go for segmenting, using snipper/chopper and or densifier (with same density) linear objects to points, and create a densitymap of the points; highest concetrationof points is highest density of objects. Pol
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thanks Gio, I will look deeper in that option. will update the thread with the results. Thanks again

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