There was a similar chair offset case here.
http://moi3d.com/forum/messages.php?webtag=MOI&msg=1773.1

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Hi Danny, yeah that one though did come to a singularity/pole point, and stuff that had a pole was pretty much broken for offsetting in v1. That particular area did get improved quite a bit with one of the geometry library updates in v2 though, although it looks like that one still doesn't work.

The offsetter also seems to be pretty finicky about doing things that go through several inflection points like these shapes have.

- Michael

Hi yannada, that looks like a different kind of offset bug than the high degree one.

Your object is somewhat large in unit size, if you shrink it down to 1/100 of its current size then some offsets will start to work although not all:



Also it will start to fold in on itself if you go very far away:



I'll see if I can take a look at where this one is failing, maybe there is a possibility for me to tune it up.

- Michael

hmmm I should make a miniature one. "LOL"
Thanks Michael, it will be much appreciated if you could work it out. I'm stacked with few concepts here.

Also note in my case all is needed is 3-7 mm offset (injection molding)

Just to be clear, when he says scale it down, it's only to perform the operation, then you can scale it back up again! Correct?

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Hi Burr, yup that's right.

Yannada - that's how you can get your 3 to 7mm offset working currently.

Select your chair, then run Transform/Scale, type 0 <enter> 0.01 <enter> to scale it around the origin to 1/100 of its current size.

Now you can use surface offset in the range that you want, which are now values of 0.03 to 0.07 . I tried several values in this range, like 0.03, 0.04, 0.05, 0.06, and 0.07 and they all work. (above 0.08 or so seems to start to be problematic).

When you are done, you can select the chair and its offset and scale back up if you want.

That will produce the result you are looking for right now.

It may not be too hard for me to adjust the tolerance to be a relative tolerance which may improve things to work better at your original scale, but you can get this done with the above procedure right now.

- Michael

Cool...

So it's not more easy to work only without unity?
It's very astonished that you must works to 0.001 to 10 000 :)

Hi Pilou, well the tricky part about these things is that many operations are approximations where there is a mechanism that repeatedly refines a result until it is accurate enough.

If the accuracy level is set to be too high, then it can produce really dense results, like with many control points in it.

It turns out that the surface offsetter in the geometry library would stop trying to build the offset when it hit a certain number of points. That was causing many of these offset problems. But I've been able to change that so that it will not be so sensitive in the next beta.

- Michael

Hi yannada, well some good news!

I was able to make a few strategic fixes to the geometry library which helps surface offsetting out quite a bit.

Both of your examples, the G2/G3 filleted box and the chair will work in the next v2 beta and you won't have to scale your chair down in size to do the offset in the next beta.

Danny, that other chair that you linked to will also work but it seems to have a tiny fold in the tip of it so that area is a bit messy when offset.

But it looks like a pretty significant step forward in this area for the next beta.

- Michael

Cool Michael!
Good to hear.

Cheers

SUPERMAN

No! He is bedda dan dat!