PolyPen knife does not cut if there is a selection

[jlampel]

PolyPen's knife works great if no verts or edges are selected but does not work if there is an edge selected.

It feels intuitive to select an edge before making a cut, and even though that's not necessary I think it should still be supported.

Really any time the mouse is over a face, it should cut instead of add geometry. There is no case that I can think of where we would want overlapping geometry while retopologizing, so I think it's a safe assumption that would make for a big workflow enhancement.

But there's also not really a scenario where I'd want to make a face that has almost 0 area. Can there also be a rule that if the area of a face is under a certain threshold or the point is within a certain distance from an edge, it instead makes a cut?

[vxlcoder]

the main issue should now be fixed and ready for testing.

will still need to work through handling the non-overlapping geometry.

also, PP does not handle having an edge selected and then clicking on an edge or vert that shares a face with selected edge. this should probably cut the face, but I'm not fully sure what makes the most sense when hovering an edge. created issue #1407 to track this.

[jlampel]

Awesome, this does solve the main problem. I really like the way the visualization snaps to the selected edge when the mouse is close 👏