Building a grid shadow lantern

[frank beckmann]

Stupid title - no idea otherwise.
Deal was to built a spherical structure projecting a grid shadow - so to speak:

Cheers
Frank

 

[Swizl]

Now that is really cool! Danke

 

[Jeanny]

Clever! Unique!
I love the lighting/shadow effects!
It mesmerizes me.
I keep coming back to watch it.

Thanks for sharing!

My Best
Jeanny

 

[Helmut]

* Years ago I did some modelling with Riemann spheres and Möbius transformations (related to the geometry Frank is showing). As Frank has done, I used a spot at the "north pole" of the rotating sphere for stereographic projection.
* This turned out to be very simple modelling in C3D. Admittedly, the result was largely serendipitous. Despite being lucky to have good spatial imagination, this was the result of chance and experimentation.
* Try a rotation on the X- / the Z-axis and see what happens. Great images, even you don't care about these being complex numbers on an infinite plane.
* Using stereographic projections with tori and loxodromes is also great fun. You can simulate the inversion of a torus and other totally weird 3D transformations, all without the help of alcohol and psychedelic drugs.

 

[frank beckmann]

While I like the outcome (I´d prefer real circles ) I hardly can read your set-up.
Mine was a try of reverse-engineering the 3d-printed object from this

Spoiler: Book cover

https://books.google.de/books?id=yU...ce=gbs_ge_summary_r&cad=0#v=onepage&q&f=false

First was the shadow then the sphere, then a Boolean operation - et voilá.

Cheers
Frank

 

[frank beckmann]

Here´s another one - this time grown on my crap:

Cheers
Frank