Sketch should show "Constrained".

[huguesacker]

Hi,

I have an issue on several times on a sketch which is (supposed to be) constrained, and yet, does NOT indicate fully constrained and also indicating some lines are not constrained (meaning blue color, instead of black).

When I try to move sketch components it is impossible, and also, if I try to add other measures, like angles, it says that it is over-constrained: meaning that it is indeed, constrained. This is surprising; do I have something wrong ?

Please see the picture below !

Thanks.

Hugo

[huguesacker]

@HughesTooling I fully agree with you !! The dimensions have definitely an impact on what is seen as correct or not. Rounding the values has also something related with the problem. Like if accept certain values given of writing new ones. Some times, the undo-redo has also an impact.

[huguesacker · Accepted solution]

To all: I've submitted a ticket to the support, explaining the case, so that programmers will address the problem.

[jeff_strater]

@HughesTooling, yes that is definitely a bug.  I tried to reproduce it, but did not have any luck.  Take a look at the screencast and see if you can spot something I am doing differently than you are.  If not, and if you can post a file that shows this, I'd be interested in having the solver guys take a look

[HughesTooling]

@jeff_strater The difference is the diameter of the circle. Don't know if you are working in mm but for me the tangent lines didn't show white on a Ø40mm but did on a Ø60.

Mark

[huguesacker]

@jeff.strater@HughesTooling@melvinbrian3d

Hi all, here is a screencast that illustrate what we have seen.

I have submitted a ticket for this behavior.

[jeff_strater]

Thanks, @HughesTooling, I can reproduce the behavior with your hint.  That is the absolute weirdest thing I have seen in months.  It just completely violates everything I thought I knew about the constraint solver.  Why would the value of the dimension affect the constrained status of a line attached to it?

I'll let the sketch solver guys know about this. 

Jeff

[whittakerdw]

I don't know if this will help you any, but what I was meaning was basically using the Pythagorean Theorem to constrain the drawing. Dimension the line vertically and horizontally and that leaves the "c" side in the Pythagorean Theorem, which constrains the drawing. 

[huguesacker]

@whittakerdw I agree with you, that it is possible to "fully-constrain" the given example. However, the point was that the sketch engine has some glitch; this has been confirmed to me by the people in charge, and they are now investigating on it. Now, rather than to waste time to find a weird way to "fully-constrain" a sketch that should be obviously constrained by nature, I just accept it like it is, if after a small time to find a problem, it appears that there is no problem at all.

Of course, if I do not find a problem easily, I launch the tool which is supposed to hilight any non-constrained object:

1) launch the text commands interface (menu File),

2) in the text area, type: Sketch.ShowUnderconstrained

This tool will automatically show the objects which are not constrained.

So after that, if the object shown is supposed to be fully-constrained, I just accept the sketch like this because the pb is due to the bug.

By the way, I have submitted the idea also, to put a button on the sketch palette, to launch this function directly (beside the stop sketch button). This would be a good help to pinpoint an object not fully-constrained.