Adding sketch constraints unconstrains other elements in certain cases

[vchanXLR7K]

I've noticed several esoteric bugs in the past with sketches, but have never really been able to isolate cases of them until I came across this one so I've decided to seek some help here.

I'm working with a sketch interacting with intersected geometry. I was able to fully constrain my sketch at one point in time, but later decided to add a dimensioned construction line instead of a raw dimension. The new construction line seems to break the 'constrained status' of existing sketch elements (square-like rectangle on middle-right side in screenshare below) only when it interacts with this particular curve (leftmost purple arc-like segment) that comes from intersected geometry. To be precise, only when I create this construction line and make one of the endpoints coincident to the 'problem curve' and the other coincident to another (constrained) sketch element does the issue occur. My screenshare below shows me demonstrating that the issue only occurs with this particular intersected sketch curve.

My understanding is that adding this rather arbitrary line and coincident constraints should not unconstrain a previously constrained element - if anything, it should overconstrain it. Dragging parts of the newly unconstrained box has no effect, before or after the construction line.

I've read around somewhere that working with imported mesh geometry might have weird side effects downstream. The intersected geometry does come from such a file (can't remember what format particularly), so it wouldn't be a surprise to me, but if anyone else has experienced such esoteric bugs with the sketcher, I would be happy to know that I'm not the only one. Also would appreciate any tips to avoid such bugs.

Unfortunately due to IP purposes I cannot share the full design file, but might be able to slice it up if need be.

[sutherland-]

Hi @vchanXLR7K 

Can you attach the file here so that we can test it ourselves?

[TheCADWhisperer]

---

@vchanXLR7K wrote:

Unfortunately due to IP purposes I cannot share the full design file, but might be able to slice it up if need be.

---

@vchanXLR7K 
Can you Attach a dummy file that exhibits the same behavior without including any proprietary data?

[vchanXLR7K]

Here's a sliced up version. I did have to remove the object whose geometry was intersected for the curve and the captured design history, but the behavior is still present and the same.

I also reverted the sketch to where it was previously fully defined - but you can just delete this 10mm dimension to change it back.