
Designing Stereographic Lampshades - jasmcole
http://jasmcole.com/2014/11/01/stereographic-lampshades/
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pimlottc
Nice writeup, looks really cool. A further step might be to 3D scan the
installation location you're placing it in to generate a completely custom
mesh that takes into account the unique geometry of the room - you could even
include the furniture if you wanted to!

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jasmcole
Interesting idea! Maybe you could do it 'live' using a transparent curved
display as the shade and a Kinect or equivalent... One thing that also bugged
me is the fact that an isotropic light source forms an unevenly-lit image, so
maybe you'd want an anisotropic emitter too.

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joshvm
At this stage you've basically invented Illumiroom and you may as well just
use a wide angle projector. You don't have full 360 coverage though so you'd
need several projectors.

[https://en.wikipedia.org/wiki/IllumiRoom](https://en.wikipedia.org/wiki/IllumiRoom)

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alkonaut
What would be really cool is to project an image that reconstructs to normal
only when reflected in a chromed cylinder used as the base of the lamp.

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Theodores
In normal 3D modelling for animation this is called 'creating a reflection
map'. A normal 3D package will just do it and in the environment you can have
more than the one 2D flat shape (e.g. the floor/ceiling here). Plus you can
accommodate a change in position of the light fixture.

In another discipline - maps - we are talking projections. Personally I would
like a globe of the illuminated variety with a paper cylinder around it
getting a Mercator projection on it.

Either way, the maths and software for this has been on the desktop for at
least 25 years (render times were a while back then).

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mxfh
You won't get a proper global Mercator map through light projection (a so
called geometric projection) from a sphere, the relation is purely
mathematical.

A _central cylindrical projection_ is what you get when you put a light in the
center of a sphere and project that on a cylinder

[http://www.progonos.com/furuti/MapProj/Normal/ProjCyl/ProjCE...](http://www.progonos.com/furuti/MapProj/Normal/ProjCyl/ProjCEA/projCEA.html)

[https://en.wikipedia.org/?title=User:Peter_Mercator/Draft_fo...](https://en.wikipedia.org/?title=User:Peter_Mercator/Draft_for_Mercator#Mercator:_the_rhumb_straightened)

You could get pretty close with Braun type stereographical for non-global uses
with a fixed light source.

[http://www.progonos.com/furuti/MapProj/Normal/CartHow/HowBra...](http://www.progonos.com/furuti/MapProj/Normal/CartHow/HowBraunC/howBraunC.html)

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pmoriarty
I misread the title as "Designing Steganographic Lampshades". Now that'd be
cool.

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srean
Ha! Dyslexics untie. After I re-read the title correctly I half wished this
would be about projecting random dot stereograms on the ceiling / wall.

Dot stereograms might be hard as it would be difficult to get fine dots. But
in principle it should be possible to project stereograms. That would be one
perverse pun on 3D.

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mxfh
You could go full circle by mapping a tessellated tile-able projection like
Peirce quincuncial back onto the spherical lampshade via the inverse
stereographic projection.

[http://www.jasondavies.com/maps/peirce/](http://www.jasondavies.com/maps/peirce/)

[http://math.ucr.edu/home/baez/week229.html](http://math.ucr.edu/home/baez/week229.html)

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Kliment
To improve printability you can make a thin translucent shell and vary the
thickness rather than having holes.

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cturhan
That's great. Very nice idea. How did you do that 3d animation?

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Mizza
Awesome post! I think the geometric pattern is my favorite.

(And a tiny nit-pick: Banksy didn't make the panda!)

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jasmcole
You're right! I never knew, I've added a note in the post. To be fair, Banksy
has caused a lot of stencil art in this city.

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3rd3
6 hours later, has anyone printed it yet?

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colordrops
So how would you print this onto a globe?

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markbnj
Really enjoyed reading this. Great post.

