Broken Isocurves

Can you guys look at attached WIP6 file. Very simple geometry, four overlapping solids on one side, Boolean into one solid on the other. Please take a closer look at the isocurves after Boolean. Some are broken now.
This is not the first time I came across it. From what I’ve noticed it usually happens after moving solid’s edge or face and if not spotted on time eventually ends up with bad object.

Boolean.3dm (261.6 KB)

Wow, that definitely is odd. This also happens in V5, so it’s not a phenomenon related to the WIP. If you Explode your unioned object, then _RebuildEdges, you will see that the faces where the isocurves are “broken”, the edges pull away and actually become arcs!

This may be a combination of the fact that your objects are pretty small w/respect to the tolerance and the faces concerned are not trimmed rectangular planes, but non-rectangular planar surfaces. But it still should work correctly IMO, this looks like a bug to me… @pascal

If I replace the trapezoidal sides with trimmed planes, the problem disappears…


Edge tolerances on the result of the Boolean are very high… I don’t see why yet, I’ll poke at it some more. Looks buggy to me…
@AdamBBLee did you make the wedge shaped objects by moving the edge(s) of a standard box?


Hi Mitch. Yes I already have ways to deal with, it’s not a major issue as far as fixing it. My concern is that it is something that can be easily missed in early stages only to become a grievance later on. Particularly when building meshes for 3d printing. I had this happening on few occasions. And you are correct, v5 has this issue too. In my experience it’s been always related to “Move Face” or “Move Edge” first.