New Offset an Offset feature doesn't work with projected geometry

[Garyselliot]

So in the latest update I was pleased to see that we can now OFFEST an already OFFSET feature, but found a limitation, and maybe a bug on first attempt to use it.

Projected a simple rectangle from 1st component into 2nd component sketch.

Selected the projected rectangle and OFFSET it. Works fine as usual.

Then tried to OFFSET the OFFSET rectangle but get the error message:-  'cannot select offset-constrained curves that don't match the topology of parent curves. Select the original curve instead or remove the offset constraint and then try again.'

I tried selecting the 'match topology' checkbox in the OFFSET dialogue box but that didn't work, and removing the offset constraint as suggested defeats the object! Also tried it with just a straight line rather than a rectangle and get the same error message.

Tried OFFSETting an OFFSET curve that was drawn in the sketch and it works. So the problem is just with projected geometry.

[rohit.bapat · Accepted solution]

Hello @Garyselliot 

Sorry that you faced this issue.

I had a question, was "Match Topology" turned OFF while creating the first offset from the projected rectangle? Because for now Offset of offset is allowed for the offset's created with Match topology turned ON.

Can you please attach the f3d file so that we can have a deeper look?

[Garyselliot]

Hi Rohit

Thanks for your quick reply. Yes that solves it! 

Answer is no, 'match topology' wasn't turned on prior to the first offset. If I go back and do this then it works:o)

[Garyselliot]

Sorry if this sounds like a stupid question, but it's not entirely clear to me exactly what 'match topology' does, and why you might want to toggle it off / on. I now know when it needs to be on, so can you please briefly explain what it does, and when it should be turned off, or more importantly when leaving it on might cause a problem.