Rebuild imported Polysurface -> single surface in Grasshopper wt. points

Hi all,

I’m struggling with converting an open-polysurface to a NURBS-based surface using Grasshopper.

The goal is to deform the surface parametrically to create textures on a product and reimport back into Solidworks as a NURBS surface. For this, I want a uniform grid wrapped across the surface.

I’ve imported a closed polysurface model from Solidworks and extracted the required surfaces for texturing. I’ve joined the extracted open surfaces together so that it is a single open polysurface (internalised in attached .gh file) and imported them as a brep into Grasshopper.

I tried to create a point grid to convert into a surface however I have errors where I am creating intersection curves with the brep. I also am unable to generate a surface from the points - I think this is because there are an uneven number of points/row.

Is there a better way to convert the surface based on this method?

polysurface grid.ghx (942.3 KB)

Hi, @Jack_Zvaigzne,
Not every polysurface can be converted into a single surface, if that’s what you’re aiming for.
Especially if the polysurface is not continuously smooth and has trimmed faces.

I would recommend rebuilding the surfaces and simplifying the geometry to fit your further aims.
You could also try using meshes to shrink-wrap the polysurface (see here, and here).

A quick example attached below illustrates the issues.

polysurface grid_re.ghx (1.2 MB)

You might also find this tutorial useful to better understand how NURBS surfaces work.

Hi Lina,

Thanks for looking a the file - the analysis tools make sense as to why the surfaces may be too complex to work. I’ll look at simplifying the area of application as I don’t think the mesh shrink-wrap approach will work in this case.

The video was also useful to understand how the surfaces work in more detail, will bear this in mind for future applications!

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