Bug: Unroller misbehaving


The attached file has a polysurface and a curve that unroll incorrect.
Bad_Unroller.3dm (106.1 KB)

The curve ends up outside the unrolled result - it seems transformed/aligned with the other flange-

As a test I detached the other flange, the result suggests that the presence of the other flange caused the incorrect result:


Hi Willem,

It looks like the curve is getting associated with the other flange.

If you pull the curve to the flange it behaves as expected.

Hi Japhy,

Thanks for looking into it.

That is odd, for 2 reasons:
1: this curve is already the result of a pull this is reflected in point 2:
2: the maximum deviation between this curve and the pulled is 6.25278e-13

Command: CrvDeviation
Overlap interval 1 of 1:
          start: distance = 1.7053e-13
                 crvA(   964.766) = (-165.148, 227.38, 218.729)
                 crvB(   964.766) = (-165.148, 227.38, 218.729)
            end: distance = 6.25278e-13
                 crvA(   994.831) = (-165.148, 227.38, 188.664)
                 crvB(   994.831) = (-165.148, 227.38, 188.664)
Minimum deviation = 0
Maximum deviation = 6.25278e-13

Deviations of this magnitude should not yield such different output.
Regardless, do you agree this is a bug in the unroller that needs fixing, as the result is obviously faulty?

In our automated pipeline we process many-many curves like this so I don’t see a workaround option in pulling twice, especially since this might only help in this particular case and does not fix the root cause.


Thanks for the info Willem, its repeatable and I will get a youtrack started on it and we can see what this is all about.

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