Part & Surface workbench failed geometry

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drmacro
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Posts: 8870
Joined: Sun Mar 02, 2014 4:35 pm

Part & Surface workbench failed geometry

Post by drmacro »

In the following examples the a face fails geometry check and any resulting solid fails.

Here Face003 fails. It was created, using Part>Shape builder, with the 3 edges from either the sketches or edges from the previous faces.
Snip macro screenshot-95e41d.png
Snip macro screenshot-95e41d.png (140.72 KiB) Viewed 804 times
Here Surface003 fails. Similarly it was created in with the sketches and the Surface workbench.
Snip macro screenshot-736693.png
Snip macro screenshot-736693.png (136.59 KiB) Viewed 804 times
Is this something FreeCAD can master or is it an OCCT thing?

(Yes, I know there are other ways to accomplish this task...)

OS: Ubuntu 20.04.3 LTS (XFCE/ubuntustudio)
Word size of FreeCAD: 64-bit
Version: 0.20.26167 (Git)
Build type: Release
Branch: master
Hash: cef86fb1ef33f281565e35f0d75515c9b2dfe1d9
Python version: 3.8.10
Qt version: 5.12.8
Coin version: 4.0.0
OCC version: 7.5.2
Locale: English/United States (en_US)
Attachments
PartFaceFail.FCStd
(23.69 KiB) Downloaded 12 times
CurvesFail.FCStd
(55.9 KiB) Downloaded 17 times
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
Syres
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Posts: 2893
Joined: Thu Aug 09, 2018 11:14 am

Re: Part & Surface workbench failed geometry

Post by Syres »

With regard to CurvesFail, it looks like an OCC issue but 7.3 is way more stable than 7.6beta, it all seems to be an issue with the way the surface is constructed off the arc.
drmacro
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Posts: 8870
Joined: Sun Mar 02, 2014 4:35 pm

Re: Part & Surface workbench failed geometry

Post by drmacro »

Syres wrote: Wed Oct 20, 2021 2:59 pm With regard to CurvesFail, it looks like an OCC issue but 7.3 is way more stable than 7.6beta, it all seems to be an issue with the way the surface is constructed off the arc.
Yet, here it produces a valid solid...hmmm
Snip macro screenshot-f71343.png
Snip macro screenshot-f71343.png (139.82 KiB) Viewed 724 times
Attachments
LoftToPoint.FCStd
(11.46 KiB) Downloaded 15 times
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
TheMarkster
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Posts: 5505
Joined: Thu Apr 05, 2018 1:53 am

Re: Part & Surface workbench failed geometry

Post by TheMarkster »

I was able to make successful solid by lofting Sketch002 to a Part::Vertex attached to Sketch001.Vertex1, and then using that face produced by the loft in place of face003 using the solid maker tool in Curves workbench.
Snip macro screenshot-4de6bd.png
Snip macro screenshot-4de6bd.png (49.78 KiB) Viewed 683 times
Snip macro screenshot-99d21e.png
Snip macro screenshot-99d21e.png (47.57 KiB) Viewed 683 times
I was also able to make a good face using Curved Shapes workbench from downgraded edges of face003, but was unable to reproduce that success on a subsequent try.

Edit: Note that the loft does not produce a solid because the sketch being lofted is not a closed wire. It produces a face, which is then used with the other faces to make the solid.
Attachments
PartFaceFail_markster.FCStd
(23.09 KiB) Downloaded 14 times
drmacro
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Posts: 8870
Joined: Sun Mar 02, 2014 4:35 pm

Re: Part & Surface workbench failed geometry

Post by drmacro »

TheMarkster wrote: Wed Oct 20, 2021 4:29 pm ...
Edit: Note that the loft does not produce a solid because the sketch being lofted is not a closed wire. It produces a face, which is then used with the other faces to make the solid.
Hmm...I reused the same file that I used part builder with, and forgot the sketch there didn't need a closed sketch. Details... :oops:
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
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