[sketcher feature request] auto constraints symmetry

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nic
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Location: France

[sketcher feature request] auto constraints symmetry

Postby nic » Mon May 25, 2020 2:40 pm

Hello

I hope I'm in the good sub-forum.

using the symmetry tool in the sketcher works really good. But each time, I find myself constraining the newly created nodes using ... symmetry constraints.

Wouldn't it be possible to automatically create those constraints?

[edit] typo in title
adrianinsaval
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Re: [sketcher feature request] auto constraints symmetry

Postby adrianinsaval » Mon May 25, 2020 3:59 pm

+1
User avatar
Kunda1
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Re: [sketcher feature request] auto constraints symmetry

Postby Kunda1 » Mon May 25, 2020 5:27 pm

Moved to Help subforum
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openBrain
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Re: [sketcher feature request] auto constraints symmetry

Postby openBrain » Mon May 25, 2020 5:36 pm

Kunda1 wrote:
Mon May 25, 2020 5:27 pm
Moved to Help subforum
Feature requests generally are in "open discussion". ;) :lol:

@OP : could you give some details about how it would work and be used ?
vocx
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Re: [sketcher feature request] auto constraints symmetry

Postby vocx » Mon May 25, 2020 5:44 pm

nic wrote:
Mon May 25, 2020 2:40 pm
...
Wouldn't it be possible to automatically create those constraints?
How would the sketcher know that you want a symmetric constraint and not just a regular node?
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nic
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Re: [sketcher feature request] auto constraints symmetry

Postby nic » Mon May 25, 2020 8:04 pm

vocx wrote:
Mon May 25, 2020 5:44 pm
How would the sketcher know that you want a symmetric constraint and not just a regular node?
well, i don't really get your question. When I make an "item" (edge, circle, etc.) symmetric against a given axis, I would expect that the "created" nodes would be automatically constrained as symmetric

eg.

starting from this fully constrained sketch :
step1.png
step1.png (42.01 KiB) Viewed 176 times
current behavior result is :
step2.png
step2.png (17.04 KiB) Viewed 176 times

I would rather prefer (because i always found myself correcting the result in this way) :
step3.png
step3.png (21.41 KiB) Viewed 176 times
Also, as far as I remember, (and although it is not necessarily a good reference), this is how CREO's sketcher behave
chrisb
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Re: [sketcher feature request] auto constraints symmetry

Postby chrisb » Mon May 25, 2020 8:50 pm

So you think all points should be made symmetric. To be honest: that's not how I would constrain it, if I had to do it all manually. I would indeed create a rectangle and prefer vertical and horizontal constraints and add only one or two symmetries.
vocx
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Re: [sketcher feature request] auto constraints symmetry

Postby vocx » Mon May 25, 2020 11:33 pm

nic wrote:
Mon May 25, 2020 8:04 pm
When I make an "item" (edge, circle, etc.) symmetric against a given axis, I would expect that the "created" nodes would be automatically constrained as symmetric
Well, you didn't provide this explanation in your first post, so you left us wondering what you actually meant.

I think those operations in the toolbar duplicate the selected sketch but don't add further constraints. Probably adding constraints at that time is not good for the sketcher solver, so that's why it's left to the user to apply the constraints explicitly later.
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nic
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Re: [sketcher feature request] auto constraints symmetry

Postby nic » Tue May 26, 2020 6:57 am

@chrisb
chrisb wrote:
Mon May 25, 2020 8:50 pm
So you think all points should be made symmetric. To be honest: that's not how I would constrain it, if I had to do it all manually. I would indeed create a rectangle and prefer vertical and horizontal constraints and add only one or two symmetries.
well, that would work for the dummy example sketch. Making symmetry constraints has the advantage to be a generic solution, and to maintain the ability to change the initial shape, while keeping symmetry up to date.

Maybe we could keep the current behavior by default, and propose the "auto-symmetry" as an option?

actual behavior :
sym_01.png
sym_01.png (38.16 KiB) Viewed 113 times
expected behavior :
sym_02.png
sym_02.png (33.6 KiB) Viewed 113 times
@vocx
yes, maybe it's not possible to code that, but as you can see in my last example, the sketcher looks able to add some constraints by itself, although they are maybe not the more relevant ones...

But as I said above, we could keep the current behavior as a default workflow, while letting the user selecting the "auto-symmetry". What do you think?
drmacro
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Re: [sketcher feature request] auto constraints symmetry

Postby drmacro » Tue May 26, 2020 1:16 pm

nic wrote:
Tue May 26, 2020 6:57 am
chrisb wrote:
Mon May 25, 2020 8:50 pm
Just a general comment, not opinion on the proposed functionality.

I see many, adding geometry to sketches that would (in many cases) create less cluttered and easier to constrain sketches if the feature (i.e. hole, slot, etc.) were left to subsequent mirror operations. There are of course times when the shape being designed needs to be symmetric about something (axis, other geometry, etc.). In the example given (two obrounds at an angle symmetric about an axis), I'd sketch and constrain one, then pocket and mirror. Thus saving a several constraints. (Note: not knowing what the rest of the sketch looks like, I may do it differently.)

Now it may be that it's just my way of thinking out what needs to be sketched and modeled. But, I tend to like to keep my sketches as simple as possible.

Of course, YMMV, as they say. :roll:
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