I have two point feature classes, let's call them A and B. They are well-spaced and the points are non-overlapping:

Points of two types

My objective is to create a topology using these two sets of points by connecting the minimum number of A points together to form polygons each of which contains one B point. The result would look something like this:

enter image description here

I am familiar with how to use the Topology rules within a Feature Dataset to ensure that the polygons do not overlap and that the A points appear on the edges of the polygons, whereas the B points are properly contained.

I am not familiar with any way to automatically calculate/draw the edges of the polygons themselves in ArcGIS. Is there a tool (or sequence of tools) I could use to automatically group the A feature class points into the vertices of polygons and then produce an output feature class of polygons?

If not, then the solution I'll have to pursue will be to write a toolbox script to process the A and B feature classes and generate a new polygon output class. If there is a "quick" way to do this, without having to write my own Python interacting with arcPy, I'd love to know.

  • 2
    something like a TIN from A containing B? I don't know of any tool that will do that per se but you could start with a TIN, convert the edges to polygons and then select the ones that don't contain B points and remove using Eliminate with longest side option iteratively until all polygons contain a B point. Oct 22, 2015 at 2:17
  • 1
    My first thought is creating a TIN too, and the other one is to think about Thiessen polygons.
    – PolyGeo
    Oct 22, 2015 at 2:30
  • Impossible to suggest anyting, because I don't know how to reproduce 'well placed points'. Are you able to share subsets?
    – FelixIP
    Oct 22, 2015 at 6:57

1 Answer 1


Triangulate points A:

enter image description here

Create Thiessen proximity polygons for points B:

enter image description here

Intersect 2 layers. Add field area and populate it by polygons’ area. Sort table in descending order using area field. From sorted table remove duplicate (not first) records using field Tri_Index:

enter image description here

Join above table to triangles using Tri_Index for joining. Use field B_ID (points B id field) to show triangles:

enter image description here

I hope the rest is obvious and I also want to hope that pattern of points relative to each other is similar for the rest of study area

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