Impossible Curvature Junction

Impossible junction on this plane. Can’t obtain any good results on the zebra analysis and HDR maps, there’s always that little sharp corner and i can’t get rid of it, any help is appreciated.

Mig-15 Fagot.3dm (734.5 KB)


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Well your zebra striping looks reasonable, you’re going from zero curvature to some, there’s going to be a “kink” unless you make the transition area a lot bigger.

Now if I look up the actual plane, your transition looks fine–no real aircraft from 75 years ago is actually G2 smooth anywhere, they’re barely tangent!–I presume you still need to add on the bulbous bit below the rudder control surface that blends into it. If anything maybe your blend should be a bit “smaller”? Blendier? It looks almost like a chamfer, that doesn’t quite seem to be right.


Are you trying to ‘fillet’ that? what size?

might depend on design intent:

looks like another fillet challenge.

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Yeah i’m trying to “fillet” that intersection between the wing and the fusilage but I always get that kink like in the photos that I posted. The size is pretty much arbitrary, I only have a couple of blueprints for reference.


By the way your fillet looks very good, how is it on the zebra/HDR map analysis???

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VariableBlendSrf does a decent job here.


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I wasn’t sure how you’d want the back to meet with up with the edges, so I wasn’t sure how to feel about Rhino having trouble with that area – I had to manually trim the fillet onto it’s self, which I usually don’t like doing.

I think Rhino should be able to know what to do with edges automatically all the time, but I guess AI doesn’t exist yet :sweat_smile:

I’ll upload the mods I did so you can see them up close:
Mig-15 Fagot_emod.3dm (3.8 MB)

I did modify your original surfaces by rebuilding and splitting them at the midline, while I was playing with their compositions hoping maybe Rhino would fillet them easier…

Ultimately, I’d have to study more drawings of this aircraft, like the most recent one you just added, so I can determine design intent better.

But sometimes you might want to modify or evolve the design into something new maybe idk :beers: