[Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool in Sketcher workbench

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Yosyp
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Joined: Mon Jul 19, 2021 10:48 am

[Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool in Sketcher workbench

Post by Yosyp »

Title is self explanatory. Newly created geometry with the symmetry tool appear green, while, in fact, does not apply any symmetry constraint. Upon moving, one can realize no constraints have been applied, requiring manual action.
Last edited by Yosyp on Sat Sep 18, 2021 1:41 pm, edited 1 time in total.
chrisb
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Re: [Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool

Post by chrisb »

Yosyp wrote: Sat Sep 18, 2021 10:32 am Title is self explanatory.
A few more words would not hurt. I guess you are talking about Sketcher workbench? There it would be in general possible to apply symmetry constraints, however, there are cases where this doesn't work.

Here is an example with Y-axis as symmetry line:
SnipScreenshot-863156.png
SnipScreenshot-863156.png (4.82 KiB) Viewed 837 times
While for the upper line you need two symmetry constraints, you need for the lower only one.
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wsteffe
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Re: [Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool

Post by wsteffe »

chrisb wrote: Sat Sep 18, 2021 1:11 pm you need for the lower only one.
I think that also in this case you still need two new constraints.
The constraints associated with the new (symmetrical) endpoint which stays on the symmetry line may be a symmetry constraints or a coincidence constraints.
adrianinsaval
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Re: [Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool

Post by adrianinsaval »

chrisb wrote: Sat Sep 18, 2021 1:11 pm While for the upper line you need two symmetry constraints, you need for the lower only one.
will the solver fail if the lower part has two symmetry constraints? In my opinion applying symmetry constraints is a good default, when someone has a need for different constraint in some specific points he can change it manually. Maybe have two versions of the tool, one that applies symmetry constraints and one that doesn't. My guess is that most of the time you would want the symmetry constraints.
GeneFC
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Re: [Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool in Sketcher workbe

Post by GeneFC »

I suspect this may be a matter of slightly different green colors for "selected" and "fully constrained".

Gene
drmacro
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Re: [Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool

Post by drmacro »

adrianinsaval wrote: Sat Sep 18, 2021 2:14 pm ...My guess is that most of the time you would want the symmetry constraints.
My workflow does symmetries with pattern tools. This keeps my sketches easy to read, easy to make one change effect all symmetries (less error prone), minimizes the constraint requirements (thus minimizing compute time in the solver and subsequent model recomputes).

But, that's just me. :mrgreen:
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chrisb
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Re: [Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool

Post by chrisb »

wsteffe wrote: Sat Sep 18, 2021 1:33 pm The constraints associated with the new (symmetrical) endpoint which stays on the symmetry line may be a symmetry constraints or a coincidence constraints.
In theory it could be a symmetry. But the way it is implemented it is not possible to have a symmetry on coincident points - which I think makes sense.
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wsteffe
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Re: [Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool in Sketcher workbe

Post by wsteffe »

chrisb wrote: Sat Sep 18, 2021 5:26 pm it is not possible to have a symmetry on coincident points
Ok, then the requested feature (which I agree would be nice to have) could be implemented with following actions:
- Enforce a symmetry constraint on every edge endpoint (or arc center) with the exception of endpoints (or arc centers) that are placed on the symmetry axis. For the latter the coincidence constraint should be used instead of the symmetry constraint.
chrisb
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Re: [Feature request] Automatically apply symmetry constraints to geometry created with symmetry tool in Sketcher workbe

Post by chrisb »

wsteffe wrote: Sat Sep 18, 2021 6:56 pm - Enforce a symmetry constraint on every edge endpoint (or arc center) with the exception of endpoints (or arc centers) that are placed on the symmetry axis. For the latter the coincidence constraint should be used instead of the symmetry constraint.
That would be even closer to how it would be constrained manually.
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