Hi PP, so one thing that may help to explain how the mesher works is that it doesn't necessarily try to "round" the values that you enter - it's more like those values are used to decide whether to continue to subdivide some polygons further or not.

The mesher starts out with an initial base mesh that is made up of the surface subdivided down into a quad grid. Then each quad is measured and if any quad is out of the tolerance specified by your parameters (like if it has any angle greater than your angle parameter or any length larger than your "Divide larger than" parameter), then it gets subdivided, and then the measurement and subdivision continues with those pieces as well.

It does do some work specifically for circles to try and make an initial starting mesh that meets your angle parameter, but again the angle parameter in this case is used as a "tolerance", meaning that it will try to make a result where the angles between each line in the polygon circle are under the angle parameter that you have given.

Does that help to make some more sense of the results that you're seeing? I'll go over your post some more and see if I can give you some other comments.


Oh, also another thing I should mention is that the angle parameter is used in 2 different ways - for trim curves such as on the circle that you showed there, but also on surface normals. So on a curved surface the surface normals at the corners of the quad are compared to each other to see if they are within the angle parameter or not.

- Michael