Topic: Creating a Spherical Stencil

Okay, so I've got a little art project I'm working on, the basic design for which I've laid out in 2-D in Illustrator. The real-world result, however, involves the use of spheres, on which I'll be painting letters.

Here's basically what I mean:



What I'd really like to be able to do is print out each letter on a full-sheet label, cut it into a stencil, stick it onto the sphere, and spray. Of course, a flat print does not a sphere make. So, I'm trying to figure out a way to create an interrupted sinusoidal projection for each letter, which I can cut out and lay onto the sphere. (Each letter will appear twice, by the way, once on each hemisphere.)

I realize, of course, that I'm starting with a flat image to begin with, which introduces a distortion problem when it's translated into a sphere. Each letter would appear more like this in real-life:



But I'm having trouble wrapping my head around exactly what I need to do to get the final result. I was hoping maybe one of you mathletes could help out. Or maybe someone knows how to do this in a 3-D program.

As fun as it'd be to figure that all out, I think it'd be pretty rough for the actual end result.

If you can get a sheet of thin rubber (whoopee cushion?), you could cut out the stencil, stretch it over the sphere, and spray.

Could also take one sphere and project the letter onto it (light through paper-cut stencil from overhead), and cut out a stencil into an actual sphere - then drop that sphere onto other spheres (obviously the thickness of the spheres and/or whether they're hollow would factor into this approach). Might not be worth going through all of this approach if you only need one of each letter - could just use masking tape (etc.) with light-projected stencil instead.

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reisio said:

could just use masking tape (etc.) with light-projected stencil instead.

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That would be my suggestion as well.
Once you add math to the equation ( ), I usually decide the project isn't that interesting!

Rubber could be more hassle than it's worth with its easy distortion...

(Edited by DL-44 on 02-22-2008 16:17)

I had considered light projection, but the problem is I have nothing to project with. Would need some sort of focusable light, which I have no access to, unfortunately.

I was hoping maybe there was a trick using Photoshop's polar coordinates or something. Just can't seem to figure it out myself.

I remember watching a show that addressed a similar issue with hockey masks, you can watch it here:
http://www.youtube.com/watch?v=yt17zXRXlXs

Hope that helps!



(Edited by zavaboy on 02-22-2008 17:25)

I've used full sheet labels on curved surfaces with pretty decent results.

Created the stencil then printed it on the full sheet label...applied it to the surface which in this case was curved aluminum then used a blade to cut it out... spray paint... done.

Or you can put your design on disk... take it to a sign shop have it put on 'buttercut' ... stick on rubber stuff ...apply to surface peel out the pre-cut letter... paint...

I imagine if you're really concerned about the perspective on the sphere you might be able to do something with Transform/Distortion or Perspective... take a bit of fiddling but I think you'd get there eventually.

And maybe... jusst maybe this might be worth a trip to Staples or similar to see what they have in the way of stick on letters. I've got a ton of these things kicking around. Most popular brand back when was Letraset - Letratype - Font's galore... use a piece of masking tape to get your base line... stick on the letters and walk away. ..might want to spray on a fixer... lacquere maye.

As for light projection... keep your eyes open at the thrift shops...for a magic lantern type thing. My wife's been using one for years for stained glass work... but we hit the jackpot a few months ago..paid 10 dollars for a tracer...still in the box...new condition. Saw it a few days back in Michaels (arts/craft supply) $112.00 !

Anyway... I'd take a good look at the stick on letters.

Geeez I'm a windy bastard. =)

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?It is dangerous to be right when the government is wrong.? Voltaire

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NoJive said:

Geeez I'm a windy bastard. =)

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Yeah, and you talk a lot too

-_Q

___________________________________________________________________________
?It is dangerous to be right when the government is wrong.? Voltaire

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Wes said:

I had considered light projection, but the problem is I have nothing to project with. Would need some sort of focusable light, which I have no access to, unfortunately.I was hoping maybe there was a trick using Photoshop's polar coordinates or something. Just can't seem to figure it out myself.

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A special setup would be nice, but I think all you really need is a bright flood light and a dark place.

I'm an idiot. I just realized I still own a photo enlarger from my analog days. I just need to print the designs out the size of negatives.