Meshing issue

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 From:  PaQ
7710.1 
Hi Michael,

I have a very strange meshing issue with this surface (red one).
This surface was build by a co-worker using MoI 30days trial.

The strange think is that every way I rebuild the surface (loft, network, sweep) ... I can't reproduce the glitch.
So yes it's fixed, but I would love to explain what's happen to my college :)

I don't have the construction line, so I'm extracting the surface edges to rebuild the surface (that might explain why I can't reproduce the problem ?).







EDITED: 3 Dec 2015 by PAQ

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 From:  OSTexo
7710.2 
Hello,

It looks like it could be an actual geometry difference, here is the deviation analysis between the two parts.

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 From:  BurrMan
7710.3 In reply to 7710.1 
Hey PaQ,
The red surface is slightly twisted. That's causing the mesher to break up in the "Y" direction and required a "divide larger than" for what it reads as a "Long, slivery, curved" surface. The green one is straight and so the mesher does a very clean, unbroken mesh there.
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 From:  Michael Gibson
7710.4 In reply to 7710.1 
Hi PaQ, I guess it's just due to the particular way this surface is straight in one direction and has a particular amount of curvature in its other direction, that just meshing by an angle parameter alone makes some pieces of it to be subdivided and another area right next to it to not be subdivided, making for long and skinny polygons sitting right next to some subdivided ones. When you get a situation like that it's pretty easy to get shading glitches.

Like Burr says above if you use the "Divide larger than" meshing parameter, it should help to solve this - put in for example 1.0 or 0.5 in the "Divide larger than" meshing option and then look at the mesh wireframe, you should see that it doesn't have any long skinny triangles spanning the entire length of the surface anymore and should work better.

When you have long skinny triangles, any slight shape changes at the ends of the triangles tends to make for low-poly type shading glitches.

I don't think there's anything really wrong with the red surface, it's just that due to its particular shape you'll get low poly like shading glitches if it gets long skinny polygons being made right next to some subdivided polys, and meshing by the angle parameter alone just happens to give that kind of result.

- Michael
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 From:  PaQ
7710.5 In reply to 7710.4 
Hello there,

Indeed the 'divide larger than' did the trick.
Now I remember having this meshing issue with cones shape, but well, I forget about the solution :)

Thanks for you help guys, love this place.

(My co-worker seems to appreciate Moideling a lot, one converted ... 299 lefts ... )
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 From:  MarkRG (MARKRG0)
7710.6 In reply to 7710.2 
Hi, how was that deviation analysis done?

M
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 From:  BurrMan
7710.7 In reply to 7710.6 
Hey M,
Looks like rhino.
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 From:  OSTexo
7710.8 
Hello,

It's Rhino using the Autodesk / VSR Shape Modeling Plugin.
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