Loft: Split at tangents = off, not working

I’m trying to make a loft between those two curves in the attached file. Normal, with Split at tangents unchecked.
In the preview i see one surface but when i click ok the resulting surface is split into 3.
Am i doing something wrong ?

(6.0.18012.13241, 18/01/12)

Hello - hmmm - I don’t think you are doing anything wrong… I’ll see what I can find out. Meantime, I think I’d make the lower curve cleaner for a nicer surface(s).

180121 LOFT BUG_PG.3dm (62.9 KB)

It still does the wrong thing at the tangents as far as I can see. Use MergeSrf > Smooth=No to make a single surface from these if that is needed.


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Hi pascal.

Now I see that even if I extrude the upper curve, which is clean, with Split at tangents off. I still get 3 surfaces instead of one. Is it the same for you?

Hello - yes, this is where it gets… confusing. Extrusion objects are always split at tangents. I know, I know, I have lobbied for more clarity, … So if you set UseExtrusions to make polysurfaces instead,ExtrudeCrv will pay attention.

I’ll try again…


Yes, I see it does, but the Loft still creates polysurface. Thanks for tracking, SplitAtTangents=No is a good feature, should work without problems.

Kind of on the same topic and probably somehow related. Lofts, extrudes, and the like via rhinocommon in Grasshopper also preview as one surface when there is no Splitting function used (they even read in GH as untrimmed surface and can be used as so) As soon as it is baked into Rhino it becomes polysurface.

Hello - You might be able to fix this by turning off CreaseSplitting before the bake. I’d turn it back on after though.