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Re:Show HN: LitiHolo – a desktop 3D hologram printer that ma... by captainmuon on Thursday March 18, 2021 @12:34PM (#26504470)
Pretty neat. This seems like it actually exposes holograms the "hard" way, like you would do in a traditional setup (with lasers and beam splitters). A shortcut would be too directly print the very fine pattern that is on the holographic plate - basically a fourier transform of the image you want to encode. When I was in university we did a student's project on computer generated holograms and tried that - with a special ultra high dpi slide printer it didn't work, but strangely with a regular laser printer. The resolution was too coarse and the scale of the hologram was off, but it was really cool - if you reflect laser light from the plate, it looked as if the object was really there.

I the appendix we speculated that it might be possible to clevery use GPUs ("3d accelerators" back then ;-)) to do the calculation in realtime and show it on a very high DPI screen. Some time I'd really like to revisit the project with today's technology.

Re:Show HN: LitiHolo – a desktop 3D hologram printer that ma... by hologram-paul on Thursday March 18, 2021 @12:40PM (#26504540)
Actually, recording the laser light is easier currently than trying to compute out the full fringe pattern and print. In essence the light and interference pattern captured are doing real time Fourier computation at the speed of light.

3D computational advances certainly have helped, and we expect even more as our hologram printers get more advanced with time. Thanks.

Re:Show HN: LitiHolo – a desktop 3D hologram printer that ma... by phkahler on Thursday March 18, 2021 @01:06PM (#26504875)
I've been wondering if you could compute the interference pattern and then compute the view from any specific angle - possibly on a GPU. A sort of 2d way to save a 3d model.

Also wondering how feasible it is to "reproject" a hologram from one plane to another - rendering multiple "objects" into one hologram/interference pattern.

Re:Show HN: LitiHolo – a desktop 3D hologram printer that ma... by hologram-paul on Thursday March 18, 2021 @01:09PM (#26504921)
This is definitely possible and is the basis for some computational holography.

And a holographic interference pattern is definitely a way to store a 3D image in a 2D plane, and I think a part of what won the Nobel prize in physics when holography was invented.

Re:Show HN: LitiHolo – a desktop 3D hologram printer that ma... by hologram-paul on Thursday March 18, 2021 @01:10PM (#26504927)
And also the subject of the ideas like the holographic universe.
Re:Show HN: LitiHolo – a desktop 3D hologram printer that ma... by spyder on Thursday March 18, 2021 @05:18PM (#26507666)
Recent research on improving the hologram computation with deep learning:

https://spectrum.ieee.org/tech-talk/computing/software/realt...

Re:Show HN: LitiHolo – a desktop 3D hologram printer that ma... by hologram-paul on Thursday March 18, 2021 @05:56PM (#26507984)
I saw the article (it got a lot of attention talking about holograms), but I didn't see any actual holograms. I hope they get a 3D Hologram Printer so that they can actually output their computations.

And go MIT!