Some defects after extrude

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MrCedric
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Joined: Wed Sep 15, 2021 10:59 am

Re: Some defects after extrude

Post by MrCedric »

Thank you guys, now it's perfect in FreeCAD ;)
But I have tested to import in Blender to check the polygon, and :shock: the bug is syill here :cry:
I have tried an .obj, .stl and .x3d and same problem...
It should be simple, just a curve extruded, I don't understand why it creates some weird things on the edge :?:

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drmacro
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Re: Some defects after extrude

Post by drmacro »

Did you try the Blender FreeCAD addon?

Direct import in Blender of a FreeCAD model.

https://github.com/s-light/io_import_fcstd
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MrCedric
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Joined: Wed Sep 15, 2021 10:59 am

Re: Some defects after extrude

Post by MrCedric »

No I don't have the plugin at this time, I should try it thank you ;)
TheMarkster
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Re: Some defects after extrude

Post by TheMarkster »

Go to Curves workbench. Select the Path in the tree. Create JoinCurve. Select the JoinCurve, create DiscretizedEdge. Set the number of points to 300 (or you can experiment here). Select the DiscretizedEdge and create InterpolationCurve. Set InterpolationCurve property Periodic to True (so it is closed wire). In Part workbench, select InterpolationCurve and use Extrude tool.
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MrCedric
Posts: 12
Joined: Wed Sep 15, 2021 10:59 am

Re: Some defects after extrude

Post by MrCedric »

Thank you very much ;) really better !
But why my curves are so angular in my Blender import test? The curves are so smooth in FreeCAD before the extrude... :roll:

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chrisb
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Re: Some defects after extrude

Post by chrisb »

Did you try to simplify the SVG (Inkscape provides such function)?
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TheMarkster
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Re: Some defects after extrude

Post by TheMarkster »

Install Curves workbench from the Addon Manager in Tools menu.
jeno
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Re: Some defects after extrude

Post by jeno »

MrCedric wrote: Thu Sep 16, 2021 4:38 pm Thank you very much ;) really better !
But why my curves are so angular in my Blender import test? The curves are so smooth in FreeCAD before the extrude... :roll:
Please use the mesh workbench for creating meshes. There you can use different meshers. I use the internal - usually good results and fast.
And you have control over the quality (deviation, angular deflection) of the resulting mesh.
And follow the suggestion of markster
svg (bottom) vs markster (top)
svg (bottom) vs markster (top)
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The resultion mesh shows better quality where the curvature is low. The screenshot shows both meshes with flat shading.

Regards
chrisb
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Re: Some defects after extrude

Post by chrisb »

jeno wrote: Fri Sep 17, 2021 5:37 am Please use the mesh workbench for creating meshes.
Which mesher did you use? Did you look at it in wireframe mode?

Standard with default parameters looks weird:
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gmsh fails to start, probably a Mac issue.

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jeno
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Re: Some defects after extrude

Post by jeno »

chrisb wrote: Fri Sep 17, 2021 6:04 am
jeno wrote: Fri Sep 17, 2021 5:37 am Please use the mesh workbench for creating meshes.
Which mesher did you use? Did you look at it in wireframe mode?

Standard with default parameters looks weird:

Mefisto with default parameters kills FreeCAD.

Netgen with default parameters kills FreeCAD.

gmsh fails to start, probably a Mac issue.
As mentioned in my post I use the internal (aka Standard) mesher of occ. And yes, I saw the artefacts. The bottom piece shows the wrinkled surface.
I suspect that the mesh algorithm ran there in trouble in case the wire has only a very low curvature. Could be that then the allowed deviation leaves more "free room" to compute vertices. Or the import of the svg creates a wire which has a volatile gradient.
But to be honest to evaluate that is above my head.

Regards
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