Hi Micha, I've tuned up "Avoid smaller than" for the next v2 beta to avoid this problem.

So basically the way it worked before was that if a polygon had an edge under the "Avoid smaller than" distance, it would switch to a rougher 35-degree angle for the angle test in that direction (U or V direction).

It would use that adjusted angle to decide whether a polygon met the angle tolerance or not, and if not then it will subdivide the polygon.

But then the problem was that when it decided which direction to subdivide, if one direction (U or V) was under that distance (note, _distance_ was used for this part and not angle) and the other was not, it would split in the long direction. The idea was for it to literally avoid splitting something that was already small even further. However, it is not good for low poly count to do this, your example of those long and skinny objects in that cross-hatch area shows that.

Really the main intent of "avoid smaller than" is to make a rougher mesh in small areas, to help reduce polygon count. The old mechanism was trying kind of too literally to avoid subdividing small edges at all costs which actually increased overall polygon count in some cases.


So to fix this up I now use the angle to decide which direction to split in.

The way it works now is that it looks to see if U or V are out of angle tolerance, using the rough angle for a direction if that direction length was under the "avoid smaller than" distance (the same as before for this part). Then to decide which direction to split, if only one direction was out of tolerance (using the possibly adjusted angle), it will split in that direction.

If both directions were out of their angle tolerances then it will use the one with the greater angle, same as how it normally works with no "Avoid smaller than" specified.

This adjustment will now give more expected results including with "long and skinny" shapes.

I've tested it with a bunch of things and so far I don't see any problems. So I think it is an overall better way to do it. But please let me know if you see any unexpected results with "Avoid smaller than" in the next beta.

- Michael