Hi! I’m trying to use the relative item component to offset the surfaces of the dome structure, but there seems to be an error “offset mask is not valid”. Pretty new to grasshopper, can’t really find a solution to this. Any help would be greatly appreciated. Thanks!!!
The Relative Item component is used to create a relationship between two items in a data tree.
If you want to create an offset surface, try the Offset Surface component. You’ll find it under Surface / Util
Thanks for your help! If I want to give the surfaces a thickness that stays constant when I change the other parameters, how should I modify this script? Thanks again!
dome test.gh (10.5 KB)
The first thing you need to do is join the surface segments.
Grasshopper does not have a native component to offset the entire polysurface.
But you can use a script. The only way I get a closed result is if I fit curves with less control points before the lofting…
dome brep offset.gh (29.8 KB)
What is the goal? What do you want to do with the geometry?
Wow 
I stand corrected, Bravo.
I didn’t have to “fit curves with less control points before the lofting”.
Thanks guys! I’m trying to come up with different variations of the dome shell structure. Is this caused by my grasshopper version being outdated?
Yes, @martinsiegrist’s C# requires R8.
Ahh I see. Is there any way around this using r7?
R7 version with reduced ‘tolerance’ value. All credit to @martinsiegrist
I also don’t have to but the offset brep script runs quicker
thank you so much, this reallly helped!! you guys are lifesavers 
Any way you please. Thickening is notoriously difficult 
