BlendSrf not working

I’m trying to cap the ends of this sweep with a blendsrf. It works fine on one end, but the BlendSrf fails on the other. The profiles are essentially the same: same shape & point count, just scaled differently.

Why will it blend one end but not the other? Microprong Hoop Earrings broken blend.3dm (4.5 MB)

Rhino 6 - SR13

Hi Mike - make your blend surface

Explode the part and ExtendSrf the top/outer surfaces through the blend (Type=Smooth)

Trim the blend and the extended surfaces to each other:



Nice, but why would it work on one end and not the other?

Hi Mike - on the lower one, the surfaces that you extend are curving away from that blend so you also need to extend the edge of the blend surface through the extended outer surfaces in order for them to intersect.


Hello Mike,

I used the chain edges option with the blend and did it in two steps and I believe it worked.

Thank you,

Andyblend.3dm (4.6 MB)

Thanks Andy. I got that to work too. :+1:

Hi Pascal,

On the lower one, I could use chain edges and blend the top and bottom left edges to the top and bottom right edges in a single blend.

On the top one, the same workflow breaks. Why would it be able to blend one end, but not the other?

Good question… dunno yet… but you can do it in two blends if you want to do it that way. MatchSrf the roundy blend to the flatter one for position… (explode first).