[Behaviour suggestion] Merge 'Coincident' and 'point on object'

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adrianinsaval
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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by adrianinsaval »

I admit that the name "point-on-object" is too general. I would prefer "point-on-line-or-curve" or just "point-on-line", where the latter could do well in connection with the icon showing a curve.
both can be described as coincidence and are described as such in other software, there's no reason to separate the concepts. Just because they are handled differently by the underlying solver doesn't mean the user needs to deal with different tools, the purpose of software is to do this type of boring stuff for us.
chrisb wrote: Tue Jan 11, 2022 10:31 am Concerning clear concepts: with your proposal, what would it be if you select two points and a line? Right now it is clear.
we could have a simple rule: if an edge is in the selection point on object is applied, what would be unclear?
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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by GeneFC »

paddle wrote: Tue Jan 11, 2022 9:13 am But having learned bad habits shouldn't be an argument against it.
I am done with this topic. I will stick to my "bad habits". :twisted:

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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by Haavard »

I am all for this. The sketcher is way overcrowded with buttons, and this would help that.
For advanced users, issues like this is non-trivial because we use keyboard shortcuts and are proficient that way. New or intermediate users on the other hand, that first selects point or geometry, then uses the mouse to select a constraint, will probably have a better time.

If you select two points and a line, i guess it would be logical to merge the points, then attach that point to object/line? That would feel natural to me at least. And the old constraints could be available in a dropdown-menu similar to diameter/radius if some users have a niche case were they need to specify the constraint used.
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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by chrisb »

adrianinsaval wrote: Tue Jan 11, 2022 2:17 pm we could have a simple rule: if an edge is in the selection point on object is applied, what would be unclear?
It could well be expected to make the points coincident.
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adrianinsaval
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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by adrianinsaval »

chrisb wrote: Tue Jan 11, 2022 5:01 pm It could well be expected to make the points coincident.
It could, but the rules would be set in the command and once they are then we'll learn to expect those rules very quickly and it will be clear. And of course it can very well be made to apply the coincidence between the points too.
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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by chrisb »

adrianinsaval wrote: Tue Jan 11, 2022 5:14 pm It could, but the rules would be set in the command and once they are then we'll learn to expect those rules very quickly and it will be clear. And of course it can very well be made to apply the coincidence between the points too.
In a previous post paddle said that the new function should be for new users, who are not thinking about concepts, who are not reading descriptions and who don't want to spend much time learning the interface. This doesn't seem to go in that direction.

I agree that there are too many icons in the default Sketcher toolbar. Among these the geometric elements and the constraints are the essentials. To me it seems the wrong place to save icons.

An intelligent drp down icon as for the radius/diameter could help solving this, yet it is inherently different, as it should provide the possibility to have two different constraints to select from. I sure don't want to select every time a sub menu when I change from applying a coincidence to a point-on-object or vice versa.
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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by davidosterberg »

@Paddle, you have come up with a lot of good creative ideas lately. This one is no exception. Well worth discussion.

I can definitely see both sides of this one. I completely agree with the idea that going by the name point-on-object we should definitely expect that the same button can do point on point. Since point is an object. No question about that. I also like the idea of removing a button.

I think the problem is that "point-on-object" is not really what it says it is. Consider this example.
Capture.PNG
Capture.PNG (2.01 KiB) Viewed 1999 times
I would not say that the circle is coincident with the line segment. Neither would I say that the circle is on the object to be frank.
What it does is to remove one degree of freedom from the point.

The coincident constraint removes 2 degrees of freedom.

Therefore they are different in my opinion.
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adrianinsaval
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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by adrianinsaval »

davidosterberg wrote: Tue Jan 11, 2022 7:18 pm I can definitely see both sides of this one. I completely agree with the idea that going by the name point-on-object we should definitely expect that the same button can do point on point. Since point is an object. No question about that. I also like the idea of removing a button.
It's also reasonable to expect coincidence to apply to edges, specially considering this is how various other CAD softwares operate too, conforming to common practice when possible is a good idea IMO, makes it easier to go from one CAD software to the other.
I would not say that the circle is coincident with the line segment. Neither would I say that the circle is on the object to be frank.
however it is coincident with the line. By definition lines are infinite.
All edges are infinite sets of points with a mathematical definition while points are sets comprised of a single point (duh). The concept of a coincidence constraint can then be said to force a point to belong to the set of points of the other geometry. When it's edges, it can be anything in the mathematical definition of that edge, if it is a point then they must be the same.
What it does is to remove one degree of freedom from the point.

The coincident constraint removes 2 degrees of freedom.
yes, because restricting to line provides more freedom than restricting to a point, the details of the implementation don't change the fact that they are conceptually the same, constrain a point to be on another geometry.
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paddle
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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by paddle »

chrisb wrote: Tue Jan 11, 2022 6:54 pm In a previous post paddle said that the new function should be for new users, who are not thinking about concepts, who are not reading descriptions and who don't want to spend much time learning the interface. This doesn't seem to go in that direction.

I agree that there are too many icons in the default Sketcher toolbar. Among these the geometric elements and the constraints are the essentials. To me it seems the wrong place to save icons.

An intelligent drp down icon as for the radius/diameter could help solving this, yet it is inherently different, as it should provide the possibility to have two different constraints to select from. I sure don't want to select every time a sub menu when I change from applying a coincidence to a point-on-object or vice versa.
I meant new FreeCad users, not new users of parametric software, people who have work to get done. Honestly who takes the time to read all the tool description when discovering a new software. There's so much to learn. The more it's intuitive, the less the complexity the better.

A dropdown is not the solution indeed, it would just make it even more complex.

Regarding selecting two points and one line, I guess it makes twice the constraint point on object, once for both point on object line? While this is a good feature who knows about it?
davidosterberg wrote: Tue Jan 11, 2022 7:18 pm I think the problem is that "point-on-object" is not really what it says it is. Consider this example.
Capture.PNG
I would not say that the circle is coincident with the line segment. Neither would I say that the circle is on the object to be frank.
What it does is to remove one degree of freedom from the point.

The coincident constraint removes 2 degrees of freedom.

Therefore they are different in my opinion.
Yes I seen this, though the point is still coincident with the infinite line even if it's not on the segment.

I still think it makes more sens that this is one tool. It reduce the complexity, less complexity is a software easier to learn and to use. There's a reason why other CAD software do it this way.
adrianinsaval wrote: Tue Jan 11, 2022 2:17 pm both can be described as coincidence and are described as such in other software, there's no reason to separate the concepts. Just because they are handled differently by the underlying solver doesn't mean the user needs to deal with different tools, the purpose of software is to do this type of boring stuff for us.
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Re: [Behaviour suggestion] Merge 'Coincident' and 'point on object'

Post by TheMarkster »

Combining these might help new users, but will also confuse experienced users. "Where is the coincident constraint?" In retrospect, this would arguably be the way to go (combining into a single command), but doing at this point I think would add more confusion than clarity.

A drop down menu such as with radius/diameter constraints would be better, but it does require another click in exchange for removing the icon from the toolbar.

My opinion is to leave it as it is.
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