Hi snookD - your geometry in this case seems to check out fine.

It looks like you are running into a bug in the display mesher where it does not deal with the particular kind of shape that you have here.

You've got a thing that is "long but shallowly curved" + narrow here:



When converting to polygons, in a case like this it is possible for the edges to get converted to polygons with slightly different point spacing, which can then make the polygons have a self-intersecting trim boundary even though the true shape does not. Here's my quick attempt to illustrate it - you've got this kind of narrow boundary on the left but it is possible for it to get converted into some lines like the right, where things cross each other:




Once things cross each other it causes further problems with mesh generation.



At export time, you can get a proper export if you use "Divide larger than" of .1 units, that seems to give a proper export mesh generation.


It's not very good to put the display mesh generation way down to an angle of 3 though, unless you are only working on a smaller number of objects - it will generally cause a really really dense display mesh for objects so you can run out of memory pretty easily with it set to that tight.


I'd like to fix this up in the display mesher so it would look better. But it tends to be a difficult area to mess with - it is important for the display mesher to be very quick so that you don't have to wait all the time for meshes to be generated since they need to be recreated after every edit of the object. The more checking that is added to the display mesher will help to make these cases display better but also will tend to slow down the meshing process across everything. That makes it a delicate area to mess around with.

So anyway for now it is a display artifact to still ignore, but most of the time you should not be running into glitches as severe as this though.

- Michael