I have over sampled polygons that I need to simplify, without changing the shape. basically, I want to reduce the number of vertices, by eliminating the ones that are useless and have the polygons represented with the significant vertices only. I used to do that with ET GeoWizards Plug-in, but I don't have a license anymore. My table has 500.000 features, water polygons.

Any ideas?

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    Have you tried the generalize feature in advanced editing mode (of ArcGIS)? – MyFamily Jul 9 '15 at 14:59
  • My table has 500.000 features, water polygons. Advanced Editing tools are not so stable when the files are too big. – Fflavioo Jul 9 '15 at 15:02
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    Well add that to the question as it's significant – MyFamily Jul 9 '15 at 15:04
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    Please edit the question to contain key details -- it's easier on those who would answer the question to not have to review a long chain of comments for critical information. – Vince Jul 9 '15 at 15:05

Take a look at these tools: Generalize (Editing) or Simplify Polygon (Cartography)

Input your features, and an optional tolerance.

  • Thanks! The Generalize in Editing mode crashes, Simplify Polygon takes forever and doesn't gives me the result that I want. I only want to remove redundant vertices. – Fflavioo Jul 9 '15 at 16:00
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    The definition of what's "redundant" is highly subjective. It seems it will be necessary that you write your own algorithm. – Vince Jul 9 '15 at 16:17
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    The simplify tool appears to use the same algorithm (Douglas-Peucker) as the ETGeowizards tool. You might look at the help for the Simplify tool and try out variations of the tolerance size and the simplification methods to see what works best. To better understand how these tools work which might suggest what variations to try first, I'd go to the ET Geowizards help and white paper. Try them out on smaller subsets to save time. As Vince said, what you consider "redundant"/"useless"/"significant" depends on your needs and tastes, as well as the scale that you use to look at the results. – johns Jul 9 '15 at 17:17

For an FME solution, the most useful transformer would probably be the Generalizer. It has several algorithms grouped into four types.

Here's a list of algorithms:

enter image description here

From the documentation:

  • Generalizing algorithms: Reduce the density of coordinates by removing vertices.
  • Smoothing algorithms: Determine a new location for each vertex.
  • Measuring algorithms: Calculate the location of points, and return a list of these points (for example, to measure the sinuosity of a feature).
  • Fitting algorithms: Replace the original geometry completely, with a new feature fitted to a specified line (for example, to minimize the orthogonal distance to the original).

As you can see in the image below, there are a lot of settings which activate depending on the algoirthm you choose.

enter image description here

I've used this tool with pretty good results. You just have to choose the algorithm that will suit your needs and play around with the settings.

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