Thanks for your response. The â€śbadâ€ť one is the first, the one with four distinct slopes in place of a smooth bump; like you say distance is calculated using edge length, so on a grid mesh like the one pictured, a point at a certain distance on a diagonal from the origin appears twice as far from it than a point at the same distance sitting on a straight edgeloop. This has been an annoyance of mine for some time, so naturally itâ€™s the first thing that came to mind when I saw your pictures.

If I understand correctly your addon tries to find the shortest cut line between two points ? Instead of the usual method of projecting the cut from view ? (just tried it with limited success on a suzanne mesh - I am having lots of red lines, especially on the more complex parts of the mesh)

You are saying the gradient generation part is flawed and that is why we are seeing these kind of erosion patterns ?