Newbie: howto create sphere and divide it into 12 parts and make a layout


i want to make an inflatable sphere of 3m diameter.
i need the layout to be printed, so i can cut the PVC into right pieces.
How can i divide sphere into 12 pieces (strokes) and make a layout?


How much experience with Rhino do you have?

Do you know how to create a sphere? a plane?

Do you know how to use ArrayPolar? Split? UnrollSrf?

Are aware of the UnrollSrf, Squish and Smash commands?

Well, the “easy” recipe might be something like this:

Make a half circle in the front viewport say with the center at 0.
From the top viewport, rotate/copy the half circle 30 degrees (1/12 of a circle).
Loft the two half circles together to make a surface.
Use UnrollSrf to flatten the surface into a flat pattern
PolarArray the flattened pattern 12 times around a full circle…

I’m not in front of my computer now but I think that should work…


The arraypolar is working. but the split gives me problems.
i get the error: Split failed, objects may not intersect or intersections my not split object.
i can’t seem to select 1 slice…

Any further help?

Can you upload a .3dm file with the geometry? You can use the vertical arrow above where you type a post.

split_sphere.3dm (1.3 MB)

Here you are.

Thank you to share your thoughts on this post on financepolice. It really helpful for me.

This is my method… (file in cm)

Beachball.3dm (157.1 KB)

Hi, thanks… this is most usefull…

What is a wanted to print 1 slice in real size?
How can i print that?
my beachball should have a radius of 0.6m

Well, you’ll need to find a printer that can do around 2m long (only about 31 cm wide though, so an A3+ printer might do it if it has sheet feeder). I guess one way to do it would be to create a custom sheet size and either print that directly if possible from Rhino with your printer driver, or print as PDF, then print from something like Adobe reader…

Otherwise you will need to “tile” the print into several sections.

I’m here at work at the moment and i can print to a A0 plotter if i want.

Where can i set the size of 1 leaf ?

Well, if you model it at 1:1, the unrolled surface should be real size. You can then print at 1:1.

i can print it at 1:1, but is it the same as model it at 1:1 ??

how big is the beachball bow? 3meter in diameter?

I thought you said 0.6m in radius…

That will make the unrolled slice something like 185 cm long and 31 cm wide.

A 3m diameter beachball segment will be 1.5/0.6 = 2.5 times bigger in both dimensions, i.e. more than 4.6 meters long.

Can you cut the sphere in 2 ?

so the leaf will be only half the size?
It will be easier to print…

Sure, just draw a line in the middle of the unrolled part and trim away one half. Or, do the whole procedure with a quarter of a circle instead of a half-circle.