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Designing Stereographic Lampshades

190 points by jasmcole 12y ago

Mizza 12y ago
Awesome post! I think the geometric pattern is my favorite. (And a tiny nit-pick: Banksy didn't make the panda!)
- jasmcole 12y ago
  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.
pimlottc 12y ago
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!
- jasmcole 12y ago
  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.
  - joshvm 12y ago
    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
markbnj 12y ago
Really enjoyed reading this. Great post.
mxfh 12y ago
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
Theodores 12y ago
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).
- mxfh 12y ago
  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/ProjCEA/projCEA.html http://www.progonos.com/furuti/MapProj/Normal/ProjCyl/ProjCE... https://en.wikipedia.org/?title=User:Peter_Mercator/Draft_for_Mercator#Mercator:_the_rhumb_straightened https://en.wikipedia.org/?title=User:Peter_Mercator/Draft_fo... 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/HowBraunC/howBraunC.html http://www.progonos.com/furuti/MapProj/Normal/CartHow/HowBra...
alkonaut 12y ago
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.
cturhan 12y ago
That's great. Very nice idea. How did you do that 3d animation?
colordrops 12y ago
So how would you print this onto a globe?
3rd3 12y ago
6 hours later, has anyone printed it yet?
pmoriarty 12y ago
I misread the title as "Designing Steganographic Lampshades". Now that'd be cool.
- srean 12y ago
  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.
Kliment 12y ago
To improve printability you can make a thin translucent shell and vary the thickness rather than having holes.

190 points by jasmcole 12y ago

Mizza 12y ago

Awesome post! I think the geometric pattern is my favorite. (And a tiny nit-pick: Banksy didn't make the panda!)

jasmcole 12y ago
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.

pimlottc 12y ago

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!

jasmcole 12y ago
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.
- joshvm 12y ago
  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

markbnj 12y ago

Really enjoyed reading this. Great post.

mxfh 12y ago

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

Theodores 12y ago

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).

mxfh 12y ago
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/ProjCEA/projCEA.html http://www.progonos.com/furuti/MapProj/Normal/ProjCyl/ProjCE... https://en.wikipedia.org/?title=User:Peter_Mercator/Draft_for_Mercator#Mercator:_the_rhumb_straightened https://en.wikipedia.org/?title=User:Peter_Mercator/Draft_fo... 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/HowBraunC/howBraunC.html http://www.progonos.com/furuti/MapProj/Normal/CartHow/HowBra...

alkonaut 12y ago

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.

cturhan 12y ago

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

colordrops 12y ago

So how would you print this onto a globe?

3rd3 12y ago

6 hours later, has anyone printed it yet?

pmoriarty 12y ago

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

srean 12y ago
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.

Kliment 12y ago

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