Free-formed surface with a restrained edge?

I am fairly new to Rhino so please forgive my question.

I have a free-formed surface that using control points I have gotten close to the shape that I want.
However I need one of the edges to be a precise match to a specific curve.

Is there a tool in the program which I can use to force that edge into the precise shape I want?

In the below example image I am hoping to have the top edge of the surface exactly follow the red curve.

Thank you for your help.

Hi Dave - use MatchSrf to suck that edge over to the curve - you may want to fiddle the ‘match by closest points’ setting and look at the preview before accepting.


Does that force it to match 100%? It doesn’t when I try it in that quick example I knocked up. It gets close and I should be able to work with that but a way to have it 100% match would work better for me.

thanks for the quick help

Hi Dave - you may need to add some knots in the vertical direction (InsertKnot), use MidPoints=Yes, in the areas where there is not enough control in the surface to hit the curve. The ‘refine’ setting in MatchSrf should add the necessary complexity as well, but I find it tends to over do it sometimes - try both.


You can also try deleting the top row of surfs, and using _EdgeSrf to create a new row which will perfectly match to the red line.