There is a routing issue in the QuickRouter, and have spent some time reproducing it in the MindFusion.Diagramming Demo.

In certain situations routing between two nodes can be interrupted by another node below it, provided the node below it was added to the diagram before the other two nodes.

Open the attached XML in the MindFusion.Diagramming Demo, select the top two nodes and their link, then drag them down about an inch with the mouse. The routing will unnecessarily bend more than it should.

Now, delete the node at the very bottom of the diagram and try moving the top nodes and their link again. The routing will not bend unnecessarily and work as expected.

Also, if you then re-create the third node at the bottom, the top nodes will route correctly. They only route incorrectly when the bottom node was created BEFORE they were.

This routing bug is causing an issue in our product with complicated diagrams.

See the attached XML and png files.

We use a UBendMaxLen of 0 in our product, and it still does this behavior in similar situations. I have attached a screenshot of how this behavior looks in our product. You can see in "UBendLength 0b.png" that it routes correctly, but in "UBendLength 0b.png" it has the bad routing behavior of the previous examples. LinkRouter is QuickRouter, Granularity is Normal, UBendMaxLen is 0, and TurnCost is 100.

Because the Demo project does not allow me to tweak the UBendMaxLen settings of the QuickRouter, I can't exactly duplicate this behavior in the demo project and know if it's still an issue when the UBendMaxLen is 0.

If it was possible to change the QuickRouter settings in the Demo project, I could attempt to provide you another XML example that reproduces what we are seeing in our project as shown via the attached screenshots.