I’m new to Rhino for Mac so I apologise if this is a very basic question.
I’m trying to model a double parabolic roof something like the attached image. I’d like a true parabolic curve to be along the long and short axis of the roof and the perimeter to be as the lozenge shape shown. I have drawn this from 9 free form curves that have been lofted and then blended. I don’t have access to RHINOMEMBRANE is this needed?
The model you sent does answer the question but I think I asked the wrong question!
The curves on the model I posted are Splines “S” shapes and this is what I am after so the roof flattens towards the edge. Perhaps this makes makes no difference, what you seem to have shown is splitting into quarters and presumably lofting a segment?
I created one quarter using Sweep2 and then used Mirror to create the other three segments. If a single surface is desired the segments could be merged using MergeSrf.
I don’t know how precisely the model have to be but for that sketch, you can model it by revolution and then, scale 1 dimension to get it longer like the AA section.