How to manage constraints in Sketch?

[lure23]

I'm again confused with what should be a trivial issue.

How to change the constraint of the blue dot to tie to the circle's mid point instead of its outer rim (as it now is)?

I don't seem to find a way to remove the current, automatically created constraint. I'm sure it's there (where)?

Here's a short video to accompany: Sketch constraints problem

I would expect changing the drop down menu (now saying 'coincident') to 'MidPoint' would simply do the job. It doesn't.

I also didn't figure out the logic on how to get the textual drop-down (as in the picture) and when I get the icons only one? In general, I find this multitude or redundancy of controls troublesome (it's doing the same as the dialog choices to the right, right?) Can someone tell me how this works, or where to find a tutorial on this? Thanks.

[NicolasXu · Accepted solution]

Hi Asko,

Thanks for asking the questions, and letting us know your experiences. Keep them coming!

To answer your questions:

- There is already a coincident constraint between the left end point of the line and the left circle. To achieve the design intent, the logic is deleting the existing constraint, and then attaches the end point of the line to the circle’s center point. You can either add new coincident constraint or drag the end point of the line to the new location, after deleting the existing constraint.

- The Midpoint constraint would refer to the mid-point of a straight line, typically, when you want to start a line from the mid-point of another line.

- Please refer to the video for details: https://dl.dropboxusercontent.com/u/73595450/SketchConstraints.mp4

- For the drop-down control, it’s intelligent to infer the available constraints based on the selected geometries. For example, if you select two lines, there should be no Coincident constraint. Yes, from the functionality’s perspective, the control is doing the same as the dialog choices. However, one of the benefits the control provided is saving the room of graphics area & less mouse movement.

Please feel free to let us know if any more questions.

[lure23]

Thanks, Nicolas

I am slowly learning to cope with Sketch mode. It's not simple, since one needs to understand in which submode one is (certain things are possible only at a certain stage, s.a. removal of constraints). But now I can do more than when I wrote the entry.

That doesn't solve all the problems, though.

As I can show in this video, the point still doesn't snap to the circle mid point.

     Video: points don't snap

It is probably because the circle center point is already constrainted by a 'fix'. Cannot I have multiple constraints on a point? In your video the snapping happens without a problem.

I appreciate the intelligent select-first tooling (should be applied throughout Fusion 360, which it isn't).

Thanks for showing the 'midpoint' in action. I always thought it meant the mid point of arcs, circles etc. only. Never thought of the length-wise mid point of a line.

[NicolasXu]

Hi Asko,

Yes, when dragging sketch geometries, Sketch need consider the existing constraints to ensure the selected geometries are not fully constrained (i.e. can be moved).

In this case, it’s better to directly add the Coincident constraint instead of dragging & snapping.