Bug: Unroller misbehaving

Rhino
1

Hi,

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-

image
image972×384 28.7 KB

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

image
image932×341 22.7 KB

-Willem

2

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.

3

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.

-Willem

4

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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