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Comment by numpad0 | Hacker News Reader

Looking Glass is just lenticular sheet glued to LCD, same technology as cheap 3D postcards and stickers from the ‘90s made of vertical grated plastic that you tilt left and right and picture changes. Probably not even 3D. Acrylic block part is just a gimmick as well.

But reportedly they execute that principle super well, gimmick part included, to the point it looks almost VR.

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The interesting thing is that if the lenticular lens is done with mini spheres instead of mini-cylinders, it should be possible to create a more fully holographic effect, given a sufficiently high-res base display. Basically a light-field camera in reverse.

(I am sure they have thought of this by now ...)

Fovi3D (http://www.fovi3d.com/) makes this kind of light-field display based on microlenses.

One challenge here is the tradeoff between spatial and angular resolution. If you're generating a 4x4 lightfield starting with a 2160x1440 display, you only end up with 640x360 superpixels.

The company I work for (https://www.leiainc.com/) makes a display that can switch between light field and 2D, so you can have the best of both worlds.

Yeah, that's not remotely accurate.

45 angles for each pixel:

https://www.youtube.com/watch?v=-EA2FQXs4dw&t=4m18s

That's far more complicated than a lenticular sheet glued to LCD.

Undoubtedly it's harder to build, but it is the same technology.

Here's an article which discusses it, and it appears to explicitly not be lenticular.

https://www.engineering.com/ARVR/ArticleID/17613/In-Through-...

"There’s a lot more to the evolution, enough for a book on the subject, but if you had to create a list of what kinds of technology and methodology went into the Looking Glass (since they do not list it), it might look like this:"

Pure speculation.

That's not what that article says. It's speculation from before the display launched. Here is a later article in which the founder of the company says it is lenticular:

https://hackaday.com/2018/11/21/supercon-alex-hornsteins-adv...

"since he happens to be head honcho at a holographic display company he can show us the result. Looking Glass Factory’s display panel uses a lenticular lens to combine the multiple images into a hologram, and is probably one of the most inexpensive ways to practically display this type of image."

I was wrong - Miraste shard an article where apparently the combining technology really is a lenticular lens.

So, it's a much higher end Nintendo 3DS.

Except there are 45 images instead of 2.

Which means 45 pixels under each lenslet.

No actually. The Nintendo 3DS uses parallax barrier technology, which is significantly newer technology than 100+ year old lenticular tech which powers Looking Glass and most 3D devices. That's why the Nintendo 3DS has such good image separation and reduced ghosting compared to cheap Chinese 3D phones and Rokit IO Pro 3D.

That’s wrong: technically it is nothing like the vertical grated sheet you see on cheap 3D posters etc.

At 6 min 30 in https://www.youtube.com/watch?v=-EA2FQXs4dw they show the pixel sub mapping - and it isn’t just vertical bars.

Edit: If they used a vertical grated sheet, there should be vertical lines at high contrast edges at a 45 pixel pitch. look at the green book at 6:22 and close-up at 6:27, and there seems to be vertical smear (not just what you might expect from horizontal smear). Example of a 3D lenticular print without the lenses to compare against: https://cdn.instructables.com/FKG/KDGQ/I0290WOV/FKGKDGQI0290... from https://www.instructables.com/id/Computational-3D-Lenticular...

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