Moi STLs contain self-intersecting edges ( Teeny bug report )

 From:  Michael Gibson
733.4 In reply to 733.3 
Hi Crusoe - there are a couple of settings you can mess with that can help to avoid long skinny triangles.

Expand the Meshing options dialog to the detailed options by clicking on the little down arrow.

There are 2 settings here that can help - the first one is "Divide larger than". You can enter a distance here and any "surface quad" that has an edge longer than that distance will get subdivided. "Surface quad" is one of the stages in the meshing - first surfaces are divided into quads, then n-gons are formed where there are trimming curves on the surface, and when doing triangles the n-gons will be triangulated for the final STL result.

So for instance if you have some long skinny triangles you might try entering a distance of 2.0 there - that will cause polygons longer than 2.0 units in size to be diced up which can help make them more regular sized.

The other settings that can help is "Aspect ratio limit". This is also focused on surface quads, except instead of a distance it is a ratio of long side to short side. So for instance if you enter 2.0 in for "Aspect ratio limit", it will divide any quad that has one side more than twice as long as the other. This one is probably actually a little easier to try than the other one since it isn't scale dependent.

Usually manipulating those settings can eliminate the creation of long skinnys. I'd like to do some stuff in the future to try and automatically detect and eliminate them but it isn't very easy to add it right now because sometimes I can't tell if there are going to be long skinnys until right at the end of the whole process.

- Michael