Ruled Surface between two curves

Dear bloggers

i am new grasshopper user,experincg problems with ruled surface or loft.
I need to build a surface between two different curves: one is a triangle and one is a circle. The problem i have is that surface is twisted and i don’t understund why… it would be very kind if you help me. I am attaching some pictures for better understanding.


Thanks a lot.

You will need to most likely flip one of the curves or change the seam of one of the curves.

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I already tried to flip the surface and work on seam… it still has a twist.
I don’t understand how the “ruled surface” works and the direction of extrusion, that should be gradually from the triangular section to the cicle along the Z axis…

Best to upload your gh file, internalising any data, so people can take a better look. If you’re not sure how, take a look at number 3 in the link below.

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I already tried to flip the surface

No, flip one of the curves (flip curve component), then make the surface.

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i did not know. It would be much better, thanks a lot :slight_smile: (16.3 KB)

The easiest way is to use Mr Pryor’s very useful “Align Curve Seams” component from Pufferfish.

Edit: I noticed a small error in the file I uploaded, so here it is again. (16.3 KB)


i needed this plugin before :joy::joy::joy: , top, thank you so much

You can do it using gh native components (see the attached file for an alternate option), but Align Curve Seams makes it a bit more straight forward. (18.8 KB)

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Thank you very very very much, yes i saw. the next step is to understand if there is a math fuction that describe better the curvature. i definitly need more controll points and more sections.
Here the pillar detail.