Skip to main content
Question

Dissolving Polygon Inner Lines

  • June 12, 2017
  • 3 replies
  • 235 views

I have several overlapping polygon layers and I want to dissolve all inner lines leaving just the outermost boundary to a couple of polygons then invert the layer revealing just the remaining area. What is the best workflow?

This post is closed to further activity.
It may be an old question, an answered question, an implemented idea, or a notification-only post.
Please check post dates before relying on any information in a question or answer.
For follow-up or related questions, please post a new question or idea.
If there is a genuine update to be made, please contact us and request that the post is reopened.

3 replies

david_r
Celebrity
  • June 12, 2017

Not sure I understand the question, but some transformers of interest could be

  • Dissolver
  • Clipper
  • DonutBuilder
  • DonutHoleExtractor

Maybe also look at the AreaOnAreaOverlayer and the _overlaps count attribute.

A small drawing of what you want to achieve would be helpful.


redgeographics
Celebrity
Forum|alt.badge.img+62

The Dissolver that @david_r suggests will combine overlapping or touching polygons into a single one. To invert the layer can use the Clipper but you'll need to have a polygon to clip from, which needs to be bigger than the polygon you're clipping with. Technically that can be solved by routing the dissolved polygons through a BoundingBoxAccumulator too and then put that into the Clipper as the Clipper feature with the original features as the Clippee, like this:

The question is: is this what you want? That bounding box would touch the extremes of the dissolved polygons, no extra margin around it.


gio
Contributor
Forum|alt.badge.img+15
  • Contributor
  • June 12, 2017

I'd use a concave hull accumulator (rather then a BB) with a setting for alpha that just closes any boundary opening the dissolved polygons leave. (try halve distance of (smallest) opening).