Surfaces to brep to new single surface

I have a doubly curved shape that I didn’t build. It consists of several different surfaces. I can join it as one brep in Grasshopper. Now, I want to turn it into one single surface in order to apply transformers on it

(derives from this thread)

A selection of surface points are to be lifted.

How can I turn it into a new surface?
I have tried:

  • Contours (in order to extract the below) that I also extended to get better results
  • patch (not so good results, but right now the best)
  • Network of surfaces doesn’t work
  • surface from points doesn’t work
  • Loft and Fit loft both make inaccurate results, handling contour curves as if they were flipped…

Any suggestions?

It mainly depends by the shape, but you could draw a grid under your shape and for each point make a vertical line and with that an intersection with the shape, then you use those interception points to create a new, single, surface.

But after that?
Patch is to inaccurate and surface from points need a continues value in U-direction…

If you have something to show it would be better… its difficult to talk over words…
Also, if you have a recurring shape, its good to use gh, but if the shape is completely different each time, its faster to do things directly on rhino.

Hi, I think i have the same trouble, I want a to convert a brep to a surface. I already converted a mesh to a brep, so this polysurface has a lot of faces. I already tried doing an intersect two sets, between the brep and some cutting planes to obtain curves, but the loft doesn’t seem to be working, attached are some images of the brep

That shape is not possible to be a single surface, you might be able to get a trimmed surface or surface patches. Look into T-Splines if on Rhino 5 or try this plug-in:

Good mesh 2 nurbs solutions are not easy or cheap.

I’m sorry if don’t understand well, but I’m new to Rhino. My objective is to have two separated surfaces from this brep. I tried splitting the brep, like this
Is it possible to convert these into a surface??

A nurbs surface has 4 edges. As far as I see your 2 surfaces each have 6 edges. You will need to find a way approximate the untrimmed nurbs surface and then retrim. Or break your surfaces up into patches that use 4 edges.

It looks like a wrist / part of an arm.
It is not comparable to my initial post - your geometry is more like a pipe with an extra hole.

I would rebuild the pipe-ish shape and then cut the holes out.
Do a contour alon the whole shape and join the open curves over the holes. Create a surface from that and then cut out the holes.

I’ll try that thank you both so much!!

Finally did it, a single surface

I couldn’t have done it without your help, thank you!!

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