Question

Clippees on Clipper Boundary using a donut Clipper does not work as expected.

  • 25 April 2018
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Userlevel 6
Badge +32

When using a donut as a Clipper the Clippees on Clipper Boundary setting does not work like described in the documentation. It says:

This parameter directs what action should be taken with Clippee features that lie entirely on the boundary of the clipper.

Treat as Inside: These features that lie on the boundary are output via the Inside port. Treat as Outside: These features that lie on the boundary are output via the Outside port. Treat as Inside and Outside: Points and line segments on the boundary are duplicated and output as both Inside and Outside.

 

So the data I have is like this:

The donut is the clipper, the blue lines lie entirely on the boundary of the clipper.

The parameters I use are like this:

Single Clipper, Clippees on Clipper Boundary: Treat as Outside.

The result is like this:

The green line, on the outside of the area, leaves the Clipper correctly from the Outside port. The red line comes out of the Inside port. I think this is not correct.

Found this in 2017.1.2.0 (build 17722) and was able to reproduce in 2018.0.0.1 (build 18295). Workspaces attached.

Workaround is to use a DonutHoleExtractor and two Clippers.


1 reply

Userlevel 5
Badge +25

Same result here, it's like the Clipper either ignores the inner boundary when it comes to the inside/outside calculations or it gives precendence to the fact the line is wholly inside the outer boundary. Either way, it's not working as you would expect.

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