Holographic Cellphones Coming Thanks To AI

January 2, 2023 by Al Williams 20 Comments

Issac Asimov foresaw 3D virtual meetings but gave them the awkward name “tridimensional personification.” While you could almost do this now with VR headsets and 3D cameras, it would be awkward at best. It is easy to envision conference rooms full of computer equipment and scanners, but an MIT student has a method that may do away with all that by using machine learning to simplify hologram generation.

As usual, though, the popular press may be carried away a little bit. The key breakthrough here is that you can use TensorFlow to generate real-time holograms at a few frames per second using consumer-grade processing power found in a high-end phone from images with depth information, which is also available on some phones. There’s still the problem of displaying the hologram on the other side, which your phone can’t do. So any implication that you’ll download an app that enables holograms phone calls is hyperbole and images of this are in the realm of photoshop.

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CastAR And Holographic Print Preview For 3D Printers!

May 23, 2014 by James Hobson 18 Comments

CastAR and 3D printing

Google glasses this, Oculus rift that, CastAR… With all these new vision devices coming out, the world of augmented reality is fast becoming, well, a reality!

Here’s a really cool concept [Ryan Smith] came up for 3D printing. Using [Jeri Ellsworth’s] CastAR, [Ryan Smith] has created a really cool technical illusion to demonstrate visual prototyping on his Makerbot. Using a laser cutter he’s perforated the front plastic panel of the Makerbot, which allows a semi-transparent overlay that when you use the CastAR’s projector it gives you a holographic visual effect.

The glasses track the reference object (in this case, the gear) and then project interfacing gears in an animation over-top of the existing part. [Ryan] sees this as the next step in 3D printing for artists and makers because it can help give you a 3D preview of your part, for example if you’re not fully sure what scale you want it to print at, you could actually put a mating object, or your hand, behind the screen and visually see the interface!
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Retrotechtacular: Shedding Light On Holograms

March 11, 2014 by Kristina Panos 10 Comments

This week’s Retrotechtacular is a 1972 introduction to holography produced by the fine folks at Encyclopædia Britannica. It details quite admirably what holograms are and how they’re made.

Holograms are quite different from photographs, though both are recorded on film. Holography is based on the additive effects of waves: two crests of equal amplitude create a larger crest, while a crest and a trough of equal amplitude cancel each other out, causing an interference effect. The video demonstrates the concept nicely with water ripples and explains that the same effect happens with sound waves and light waves.

Lasers are the key to the intense and spectrally pure light required for holography. Incandescent light consists of too many wavelengths to be effectively split into two identical light wave sources. To create a hologram, a laser is split with an optical device into two beams. One beam is focused directly on the object being recorded and is called the object beam. The second beam is directed away from the scene through a series of mirrors and shone directly onto a film emulsion.

The film records the interference between the waves of the two beams. It appears to be blank after development, but upon close inspection reveals stripes of light and dark. When the exposed film is placed in the path of only the reference beam, the interference patterns recorded on the film split the beam back into two, recreating the scene. With the aid of a screen for projection, the hologram can be seen showing the original object in 2D. Another big difference between photographs and holograms is that even a small portion of a hologram can reproduce the entire scene, but a piece of a photograph is just that.

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Pepper’s Ghost – Halloween Ghosting

October 6, 2013 by James Hobson 17 Comments

Peppers Ghost is a classic technique for making ghosts appear in pictures, video, and even in front of live audiences. In this week’s Halloween themed Instructable, learn how to recreate the effect at home.

It’s really quite simple. By positioning a clear piece of lexan at a 45 degree angle to your “ghost” object, and having the audience (or camera) looking at the lexan at the opposite 45 degree angle, you can produce a very simple ghost effect. This is a great trick for producing some scary ghosts in your haunted house.

But wait. Isn’t this a bit too simple? This is Hack a Day isn’t it? How about making a real moving hologram, isn’t that a bit more of our speed?

Well, this is the exact same technique that is used to make real holograms — just replace that object with a projected image or video! We’ve covered it a couple of times before, explaining the Tupac hologram, and showing off a cool leap motion controlled globe hologram.

Our challenge to you is to make a moving hologram Halloween decoration. After all, you can get pico projectors for less than $100 these days, so why not give it a try? There’s a few more ideas and techniques for positioning the lexan in the video after the break.

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