Grasshopper ngon surface

how can i make the surface in the picture
I tried with ngon there is a problem in the center point

When I do it becomes a star overhead

You could try TriRemesh and get the “Dual”. (11.0 KB)

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Thank you very much for your reply, I will try it right away

How can I make this kind of surface?

how can i do to surfaces created with rail revolve

You can input any surface or Brep
image (7.4 KB)

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Seems like something went wrong with your file upload.

thanks - should be fixed now
also, if you should want remeshing with radial symmetry on a revolved surface, see this post


@DanielPiker Thank you very much i will try it

@DanielPiker @HS_Kim I tried the method you showed, thank you very much for your help

but when i make a surface it looks like a triangle
Surface does not appear as a polygon
how can i make the surface as polygon

I don’t want it to be like the blue picture

how can i make a polygon surface

You need to take the D output like shown in the file above

T gives the Triangles, D gives the Dual mesh which is polygons.

@DanielPiker how can i make polygon mesh as surface

Do you mean take a polygonal mesh and turn each polygonal face into a NURBS surface?
It would be easier if you post your file.

@DanielPiker as nurbs surface It could be the file you sent.
Can you make an example application?
in the file you sent.

I want to make a surface from the generated mesh

Thank you very much for your interest

i am new to grasshopper

Can you describe what you are trying to do and why you want NURBS patches specifically?

The polygonal faces in general will not be flat, so they can’t be made simply trimmed planes.
You can make them flat for something like a convex dome by optimising for planarity (which will change the shape a bit), though for more general surfaces with concave or flat parts this gets complicated.

You can also use patch, for which the boundaries don’t need to be planar, but it would get quite heavy to process.

NURBS isn’t really a natural thing to represent these polygonal faces with though, since they are not flat or 4 sided.
Depending on the aim here, it might make more sense to do the whole thing as mesh.


it’s a sphere, i want to do this on elliptical surface or rail rotated surfaces

on surfaces like this

I want to apply the surface in the picture

on the surface I made

mesh created but no surface

Yes, the Dual output is a polygonal mesh.
The boundary surfaces component works with planar curves. The curves of the polygonal mesh faces are not planar.

You can render the mesh, or 3d print it, or do various other processing on it. What specifically is it you want a surface for?