holographic

3 Articles

Let The Wookie Win With This DIY Holochess Table

May 8, 2025 by 9 Comments

If you have seen Star Wars, you know what is being referenced here. Holochess appeared as a diversion built into the Millennium Falcon in the very first movie, way back in 1977. While not quite as iconic a use of simulated holograms as tiny Princess Leia begging for hope, it evidently struck a chord with [Maker Mac70], given the impressive effort he’s evidently gone through to re-create the game table from the film.

The key component of this unit is a plate from Japanese firm ASKA3D that scatters light from displays inside the table in just such a way that the diverging rays are focused at a point above its surface, creating the illusion of an image hovering in space. Or in this case, hovering at the surface of a acrylic chessboard. Granted, this technique only works from one viewing angle, and so is not a perfect recreation of a sci-fi holoprojector. But from the right angle, it looks really good, as you can see in the video below.

There are actually six SPI displays, driven by an Arduino GIGA, positioned and angled to project each character in the game. Placing two of the displays on 3D printed gantries allows them to move, allowing two creatures to battle in the center of the table. As [Maker Mac70] admits, this is quite a bit simpler than the Holochess game seen in the film, but it’s quite impressive for real world hardware.

If this all seems a little bit familiar, we covered an earlier floating display by [Maker Mac70] last year. This works on similar principles, but uses more common components which makes the technique more accessible. If chess isn’t your forte, why not a volumetric display that plays DOOM? If you’re interested in real holograms, not Sci-Fi, our own [Maya Posch] did a deep dive you may find interesting. Continue reading “Let The Wookie Win With This DIY Holochess Table” →

New Camera Does Realtime Holographic Capture, No Coherent Light Required

February 26, 2025 by 31 Comments

Holography is about capturing 3D data from a scene, and being able to reconstruct that scene — preferably in high fidelity. Holography is not a new idea, but engaging in it is not exactly a point-and-shoot affair. One needs coherent light for a start, and it generally only gets touchier from there. But now researchers describe a new kind of holographic camera that can capture a scene better and faster than ever. How much better? The camera goes from scene capture to reconstructed output in under 30 milliseconds, and does it using plain old incoherent light.

The camera and liquid lens is tiny. Together with the computation back end, they can make a holographic capture of a scene in under 30 milliseconds.

The new camera is a two-part affair: acquisition, and calculation. Acquisition consists of a camera with a custom electrically-driven liquid lens design that captures a focal stack of a scene within 15 ms. The back end is a deep learning neural network system (FS-Net) which accepts the camera data and computes a high-fidelity RGB hologram of the scene in about 13 ms.  How good are the results? They beat other methods, and reconstruction of the scene using the data looks really, really good.

One might wonder what makes this different from, say, a 3D scene captured by a stereoscopic camera, or with an RGB depth camera (like the now-discontinued Intel RealSense). Those methods capture 2D imagery from a single perspective, combined with depth data to give an understanding of a scene’s physical layout.

Holography by contrast captures a scene’s wavefront information, which is to say it captures not just where light is coming from, but how it bends and interferes. This information can be used to optically reconstruct a scene in a way data from other sources cannot; for example allowing one to shift perspective and focus.

Being able to capture holographic data in such a way significantly lowers the bar for development and experimentation in holography — something that’s traditionally been tricky to pull off for the home gamer.

A Little Optical Magic Makes This Floating Display Pop

August 29, 2024 by 4 Comments

If there’s a reason that fancy holographic displays that respond to gestures are a science fiction staple, it’s probably because our current display technology is terrible. Oh sure, Retina displays and big curved gaming monitors are things of wonder, but they’re also things that occupy space even when they’re off — hence the yearning for a display that can appear and disappear at need.

Now, we’re not sure if [Maker Mac70]’s floating display is the answer to your sci-fi dreams, but it’s still pretty cool. And, as with the best of tricks, it’s all done with mirrors. The idea is to use a combination of a partially reflective mirror, a sheet of retroreflective material, and a bright LCD panel. These are set up in an equilateral triangle arrangement, with the partially reflective mirror at the top. Part of the light from the LCD bounces off the bottom surface of the mirror onto a retroreflector — [Mac] used a sheet of material similar to what’s used on traffic signs. True to its name, the retroreflector bounces the light directly back at the semi-transparent mirror, passing through it to focus on a point in space above the whole contraption. To make the display interactive, [Mac] used a trio of cheap time-of-flight (TOF) sensors to watch for fingers poking into the space into which the display is projected. It seemed to work well enough after some tweaking; you can check it out in the video below, which also has some great tips on greebling, if that’s your thing.

We suspect that the thumbnail for the video is a composite, but that’s understandable since the conditions for viewing such a display have to be just right in terms of ambient light level and the viewer’s position relative to the display. [Mac] even mentions the narrow acceptance angle of the display, touting it as a potential benefit for use cases where privacy is a concern. In any case, it’s very different from his last sci-fi-inspired volumetric display, which was pretty cool too.

Continue reading “A Little Optical Magic Makes This Floating Display Pop” →