Constrain a Center Point Rectangle

[Anonymous]

I seem to be doing something wrong.  I want to draw a rectangle and I want it to be fully constrained.  Simple, so…

I click Sketch, Rectangle, Center Rectangle.

I click the top plane to start the sketch.

I click the origin and drag my rectangle to size.

I click Sketch, Sketch Dimension.

I click a long leg of my rectangle and enter a dimension.

I click a short leg of my rectangle and enter a dimension.

Should I not have a fully constrained rectangle?  I don’t, or at least it is not all black as I would expect it to be if it were fully constrained.  I see the horizontal, coincident, parallel, and perpendicular constraints…everything that should constitute a fully constrained rectangle, yet the rectangle is still blue.  I cannot figure out what is not constrained but I am not comfortable moving on without fully constrained geometry.

I checked and I have “Sketch – Color sketch geometry based on constrain status” selected.

Is my geometry fully constrained and Fusion just isn’t coloring it correctly or is my geometry under constrained and I need to keep digging?  Is there a reliable way to know for sure?

[taylor.stein]

Hi Paul,

Great question, and thanks for such a thorough explanation! I went through your steps, and I'm seeing the exact same behavior. I believe the center rectangle is fully constrained,and Fusion 360 is not coloring it correctly. My guess is the way that the center rectangle is created is causing the coloring issue - the center rectangle being created by adding diagonal construction lines to a normal rectangle. 

When I attempt to move points, lines, or add more dimensions, I receive the notice that I'm creating driven dimensions, further confirming my guess that it is fully constrained. 

Let me know if you have any other questions!

Taylor

[Anonymous]

Ok.  "Guess" is the key word here.  Regardless of color, constraint status is ultra critical to an engineer's peace of mind.  I just did the same thing with a two corner rectangle.  I created the rectangle, dimensioned it, added a diagonal line, and finally created a point on the midpoint of the diagnonal line.  I then made the point and the origin coincedent.  Same result, no change to black color.

I'll try a few things I guess to land on a constraint method that provides the reassurance I need.

[DanielHuang]

Hi Paul,

What's the enviroment are you in? I check it the two corner rectangle will be fully constraints (displayed as black color) in "Photo Booth" enviroment. Please see the following snapshot:

I think the center rectangle has some issues here and the develop team will see more about this. Thanks for founding it.

[Anonymous]

I'm in photo booth environment.  Yes, the two corner rectangle works as you show it, but if you add geomertry to that shetch to be able to anchor it to its center, it will not constrain.  Specifically, sketch a two corner rectangle away from the origin, dimension it, create a diagonal line from one corner to another, create a point at that diagonal lines midpoint, make the point and the origin coincedent.  Should be fully constrained (black) but it is not.

So, it is not the center rectangle that is broken, it is the constraint logic.  Not sure how all of this works, and how the system determines if something is fully constrained or not, but it is not aware of something specific to the diagonal line or midpoint itself.  This was probably clear to you, but I wanted to point out that it was not specifically a center rectangle issue.  I hope that makes sense.

[HughesTooling]

Here's a link to a thread where this has been brought up before. There are\were a lot of situations where lines are highlighted as constrained when they're not and not highlighted when they are.

Mark.

[TrippyLighting]

It's not the constraint logic that is broken because the rectangle is fully constrained.

What is not quite yet working as intended is the Preview feature of coloring the objects based on their constraint status.

[Anonymous]

@TrippyLighting, the point is it is not working as it is supposed to.  It might be more accurate to say the constraint state logic is broken.

[jeff_strater]

Thanks for the great discussion, and the bug for us to look at.

I agree that this particular case is not correct.  We are working hard on fixing bugs like this in this "preview" capability.  This kind of feedback helps us do just that.

Jeff Strater (Fusion development)

[jiang_peng]

Hi Paul,

This is a known bug(FUS-18328)

Thanks for reporting this!