unroll.3dm (44.2 KB)
now it is a trimed part of a surface made with devsrf
if I untrim it I don’t see the (1.#J % ) but Area difference is within tolerance
Hi EOStam- I see this as well, thanks for the report. It looks like UnrollSrf is taking the starting area as 0 for some reason.
If you DupBorder, Untrim, then re-trim with the border curve, it behaves better.