topic Sketch offset bugs and weird behaviour in Fusion Support Forum

Sketch offset bugs and weird behaviour

Anonymous — Sun, 10 Feb 2019 16:47:52 GMT

I tried to explain all issues and ways to achieve them in the video, but a TL;DR: the offset sometimes doesn't actually constrain the sketch (reason unknown) - when this happens, even the offset arrow stays pointing in the same spot.

The offset chain select, and mouse double click are unable to select connected lines (projected from another sketch).

Also flipping the offset would be quite helpful when redesigning something.

Here's a shared copy of the design I was working in: https://a360.co/2GiZEC7

Screencast link, because editing messages with screencasts is broken:

https://knowledge.autodesk.com/community/screencast/2a6b7d8b-d582-4054-89f7-997c3a7c478d

Screencast will be displayed here after you click Post.

2a6b7d8b-d582-4054-89f7-997c3a7c478d

Re: Sketch offset bugs and weird behaviour

karina.harper — Mon, 11 Feb 2019 20:47:50 GMT

Hi @Anonymous

It looks like somehow the reference was lost on the offset - it's possible you were referencing the geometry from the linked sketch. You can see the difference in the offset when I re-do it; the dimension is connected to both lines. In this case, since the inner geometry is constrained to the linked sketch, it will become fully dimensioned.

Does that answer your question?

Also it looks like you can go in and add a dimension constraint to the offsets, so the other dimension is definitely not relating to the constraint.

As for the inability to chain select, I'm not exactly sure why that's happening. It could be because the projected sketch is on the same plane. You could try projecting and un-checking "projection link".

And to your last question about flipping, it should work by entering a negative value.

Re: Sketch offset bugs and weird behaviour

Anonymous — Sun, 17 Feb 2019 12:05:23 GMT

I'm writing this the second time because apparently starting a reply edit and then exiting by not clicking cancel (like using Back) wipes it completely from the forum. From now on I'll back up every single message HTML from this forum when posting as I keep finding more and more bugs.

As to the offset not being constrained, it was indeed the issue of referencing the geometry from the linked sketch. As even when you delete the projection, the constraints stay. Still a weird behaviour, but a little less shocking.

The chain select does work correctly when turning off the Projection Link, but as that just creates new, completely unconstrained lines, it is not really an option.

Screencast will be displayed here after you click Post.

bdb792c9-f84c-4df0-bc54-52b26792e233

I'm not quite sure if I understand you correctly, but by "the projected sketch is on the same plane", do you mean literally on the same plane? Because offsetting it produces the same results.

Screencast will be displayed here after you click Post.

c14fc1f2-e76e-4119-a26d-490ff03e8564

Also I completely forgot about negative values. Still a little unintuitive, but it does work.

Re: Sketch offset bugs and weird behaviour

karina.harper — Tue, 19 Feb 2019 18:56:36 GMT

Hi @Anonymous

Your screencasts didn't attach - if you could link them instead of embedding them that might work better.

From now on I'll back up every single message HTML from this forum when posting as I keep finding more and more bugs.

I'm going to note right off the bat that the behaviors you're seeing aren't necessarily bugs. Fusion needs to be told explicitly what it's looking at. There are some things here that are confusing Fusion and can be avoided. Fusion is, after all, a computer program that can only do what we tell it to do. It is not a mind reader; part of the learning process is learning to communicate with it in a way that it will understand.

As to the offset not being constrained, it was indeed the issue of referencing the geometry from the linked sketch. As even when you delete the projection, the constraints stay. Still a weird behaviour, but a little less shocking.

The chain select does work correctly when turning off the Projection Link, but as that just creates new, completely unconstrained lines, it is not really an option.

I'm not quite sure if I understand you correctly, but by "the projected sketch is on the same plane", do you mean literally on the same plane? Because offsetting it produces the same results.

If you need the sketch on the same plane and you need it linked, just use the original sketch. Project really should be used when the sketch is on a separate plane (for instance one created using offset plane). I think all the issues you've listed here are due to the fact that the original and the projected line are existing in the exact same place so Fusion is struggling to differentiate between the two.

Also I completely forgot about negative values. Still a little unintuitive, but it does work.

This is the intended behavior on this. You can select the offset direction initially, then if you want to go a different way you need to either make the value negative or create a new offset.

I hope that helps!