Boolean diff leads to display (geometry?) errors.

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 From:  Crusoe the Painter (CRUSOE)
346.1 
So I'm builging this weird futuristic post-apocalyptic battle trike. I made an array of some cylinders to subtract some holes out of the wheel. When I did this, I saw a strange meshing/display error.

So I tried to do just one cylinder at a time, and had the same problem.



The rear wheel still clicks and responds as an entire closed volume, it's just that part of the wheel face surface is not displaying, allowing stuff behind it to show through. Saving and reloading the file didn't fix it ( Glad I made a copy to test that! ). The 'hole' is irregulary shaped and not bounded by any curves, so it's probably a display problem of some kind, and not some funky geometry being produced.

Also, this isn't due to 2 surfaces being real close together, and showing through each other in some weird fashion. Rotate the model, and you'll see the surface has gaps in it.

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 From:  Crusoe the Painter (CRUSOE)
346.2 In reply to 346.1 
A better pic, I hid the part behind the wheel so the meshing/display problem can be seen better.

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 From:  Crusoe the Painter (CRUSOE)
346.3 In reply to 346.2 
Hmm, weird. Subtracting more cylinders fixes some parts, and causes other parts to not display.
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 From:  Frenchy Pilou (PILOU)
346.4 
Seems more prudent to make piece by piece for ovoid some curve to overlap
Wheel is here not necessary for example :)
As in reality you can add it after :)
---
Pilou
Is beautiful that please without concept!
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 From:  Crusoe the Painter (CRUSOE)
346.5 
Okay, I tried to export a OBJ of the rear wheel, to see if it was a display error, or a problem with the geometry...



So it looks like the geometry got hosed. In this image I had boolean diffed 4 of the cylinders out of the wheel, and then chose to export a OBJ file with quads + ngons.
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 From:  Michael Gibson
346.6 In reply to 346.5 
At the moment it is looking like the geometry is valid, but there is a bug in both the display mesher and OBJ mesh exporter (they share some common pieces so it is possible for them to both have the same bug) which causes the meshing to be wrong.

I'll see if I can track down what is wrong in the meshers.

- Michael
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 From:  Michael Gibson
346.7 In reply to 346.6 
Yeah, this is definitely a bug that is common to both meshers. I haven't fixed it yet but I am zeroing in on it.

In the meantime if you want to make progress with this model, you can replace that surface (and it looks like the equivalent one on the back too) with the attached version which will mesh properly.

- Michael

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 From:  Michael Gibson
346.8 In reply to 346.7 
Well, it wasn't easy but this meshing bug is now fixed for the next beta.

- Michael
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 From:  Crusoe the Painter (CRUSOE)
346.9 In reply to 346.8 
Thanks! :)
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