How to Unrolling doubly curved surfaces

It says “Unrolling doubly curved surfaces will produce inaccurate results.”
I’m having a bit of an issue with unrolling doubly curved surfaces in Rhino,
I tried with Unroll surface tool,Unroll UV ,Smash,Squish but it won’t help me. I am not an expert on Grasshopper.
Attach pic shows everything, what I need to explain here,I need to do Green or Red part separately unroll.the front part can be done in simple way.
Please help me to do this if you found a solution for this.
after flatten I use Plotter to get the accurate product.
attach with 3d file …
thanks.



forum.3dm (444.8 KB)

Dear @prabath there is a geometrical background you have to understand:

As soon as the gausian curvature is not 0 for the entire surface, it is not developable.

As physical materials like cloth, rubber and even steel-plates can be compressed / expanded while they are formed, it makes sense, that CAD / rhino offers a function to approximates the 2d / flat representation that can be cut and later deformed.

_squish is as far as i understand the most advanced command regarding those approximations.

_unrollSrf makes sense, only if the surfaces is developable

_unrollSrfUV will allow you to keep the UV-domain of the flat and curved version and also is only useful with developable surfaces

_smash is an older version of _squish

what do you need the 2d-shapes for ?
cutting some cloth / leather / sheet metal ?
it might be good, to split the parts in the middle of the curvy section - as the straight section is similar to a developable cone.

you might want to check for tutorials like this - or similar:

hope that helps- kind regards