Curved shapes on curved surfaces

Hello everyone!

I am a new user of grasshopper and I have some troubles with cutting surfaces. I have a curved surface and I would like to create on it some holes with the shape of some polylines I drew on it but I don’t know how to.
Here I attach the .gh file and the .3dm one. Thanks for your help

Curved surfaces_20_12_20.3dm (842.4 KB) (12.8 KB)

Ouch! That’s a painfully slow file. I suggest anyone who wants to look at it first disable the solver before opening it. This is much faster. (17.9 KB)

Oh, I don’t know why you rotated and reconstructed your polygons? I left them alone.

P.S. You can have the skewed polygons back by doing this: (18.6 KB)

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Thank you very much Joseph!
You saved my Univerisity project (my group and I are very new to grasshopper)

Perhaps you have good reason for creating the faceted surfaces with holes? You could also split the original surface using Isotrim (SubSrf) like this: (11.2 KB)

For what it’s worth (not much difference), I added an Align Plane component just before Polygon using the ‘V’ direction instead of the default ‘U’ orientation.

By the way, the same holes can be cut into the original surface without splitting it into fragments.

P.S. Here’s one way to do that: (10.9 KB)

Or using the corners of the Isotrim surface fragments to make the Srf4Pt faceted fragments: (13.3 KB)

I noticed that the referenced surface is semi-faceted in the ‘U’ direction (crosswise) with only four facets, not five, so I changed the ‘U Count’ slider from 5 to 4 to match that.