Best method to predicting meshing issues?

[ed.p.may]

Hi,

I wonder if anyone can suggest the ‘best practice’ for predicting mesh-issues ahead of time (issue=extra faces). For instance, If I have two closed polysurfaces:

to my eye they are the same.

If I look at the control points, they seem the same:

and if I look a the surface UV and normal, they seem (almost) the same:

but If I mesh them, I get different results:

---

So what I’m wondering is: what am I supposed to be looking at the identify and predict these kinds of results ahead of time (when modeling)? What is the difference between these two polysurfaces, and how can I ‘see’ that difference? What tool so you think I should be using to understand the specifics of these elements?

any suggestions are appreciated as always,

best,
@ed.p.may

example.3dm (3.0 MB)

[nathanletwory (Nathan 'jesterKing' Letwory)]

Meshing follows domains and control points.

Explode both the polysurface and the extension. Then select all surfaces and run PointsOn

Showing the extracted render mesh for the object on the left you’ll find that meshing follows the control points of the individual surfaces in the polysurface