MergeSrf declares too far apart yet sweep used surface edge

Stumped on this.

Margaret had in another post said

The surfaces have a better chance of merging if you use the surface edge as the cross-section curve for a sweep.

So I did.

Upper surface (purple) had its lower edge given DuplicateEdge

I then swept2 that edge to a point using two rails that started at the lower edge and met at the bottom to get the lower surface.

As such both surfaces have an edge that has to be 0mm apart ! and meet with Margarets advice,

MergeSrf says edges too far apart.

JoinEdge declares Joining Tolerance of 6.46887

now that can’t mean 6.46 units (my doc is units mm)

I zoom right in and they appear to perfectly abutt. They use the same edge so surely they must ?

No 6mm gap !

CrvDeviation shows one red square but zooming in on that to electron microscope level !!! still shows no gap.

Why ?


MergeSrf_edgesTooFarApart_share commonEdgethough.3dm (87.8 KB)

Please see Help on MergeSrf - this does not work if the edges are trimmed.

No. The gap is 6.46887e -06; that is very small…



I must have trimmed that surface sometime in the past then.
So if I create the upper using curves, then use the same curve for the mutual edge for the lower, it would work. But if I chop a bit off the surface using extractIso to get a line to use, as it was fine down to my chop line but then was not as required, duping the edge of that trimmed surface disallows MergeSrf.

I wihs it would say why, and not just gap too big.

gap is not the reason then, though it leads one to believe that by declaring such :frowning:

Join and JoinEdge and Boolean will fuse surfaces together, but I would like to blend them a bit , as per other post and pics there. MatchSrf will do so but again doesnt like trimmed edges. I cant help it, I sometimes need to trim things !