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I am dissolving polygons that are 10 meter buffers of a water layer. The features to be buffered come from a line and a polygon layer. Input and output datasets are ESRI Geodatabase (FileGDB API)

 

 

I create the 10 meter buffers using the buffer transformer. I then run a dissolver transformer to dissolve all the buffers so I do not have overlapping polygons.

 

 

However, if I run a dissolver again, I get fewer polygons in the output than were in the input. I have now run the data through the dissolver 3 times, and I get fewer polygons in the output each time.

 

 

So my question is how do I know when all my polygons are dissolved? Is it enough to run the dissolver only once? If not, how many times do I need to run the dissolver and can FME work this out for me? Can I automate this so my workspace runs the dissolver the required number of times?

 

Hi,

 

 

The final goal is to dissolve all the line by the minimum buffer amount?

 

If so, the NeighborFinder can be used to compute the value.

 

- Send every line to the Candidate port of the NeighborFinder.

 

- Specify an enough large value to the "Maximum Distance" parameter so that every line will be output from the Matched port.

 

- Use the StatisticsCaluclator to get the maximum "_distance" from the output features.

 

1/2 of the maximum "_distance" (+ tolerance) is the minimum buffer amount that dissolves every buffered area.

 

 

Tip: The Bufferer dissolves overlapped resulting areas for each group. So, if you give an attribute storing any identical value to every feature and specify it to the "Group By" parameter of the Bufferer, overlapped areas will be dissolved. No need to use the Dissolver.

 

 

Takashi
Thanks for the answer. I get the result I want when I use a group by parameter in the buffer transformer.

 

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