It’s the year 2260 and you’re being beamed from your starship to the planet below. Being a descendant of present day 3D printers, the transporter prints you out, slowly making one layer before moving on to the next, going from the ground up. The you-that-was hopes nothing spills out before you’re done. But what if you could print every atom in your body at the same time? If those transporters are descendant’s of Daqri’s holographic 3D printing technology then that’s just what will happen.
Daqri’s process is akin to SLA (stereolithography) and SLA/DLP (digital light processing). In SLA, a laser beam is shone onto a pool of resin, hardening the resin at the beam’s point. The laser scans across the resin’s surface, drawing one layer. More resin is added and then the next layer is drawn. In SLA/DLP, the light for an entire layer is projected onto the surface at once. While both methods involve stereolithography, the acronym SLA by itself is commonly used to refer to the laser approach.
Daqri’s process however, uses a holographic chip of their own making to project the light for all the layers at the same time into the material, a light-activated monomer. Their chip is a silicon wafer containing a grid of tunable crystals. Those crystals control the magnitude and phase of light reflected down into the monomer, creating a 3D volume of interference patterns. The brief description of the process says that a laser is used to shine light onto the crystals, so there’s probably still some scanning going on. However, in the video, all of the object being printed appears illuminated at the same time so the scanning is likely very fast, similar to how a laser in a light show seemingly paints what appears to be a 2D shape on the side of a building, even though it’s really just a rapidly moving point. There’s also the possibility that the beam’s point is large enough to encapsulate all of the chip at once. You can see a demonstration of it in the video below.
If you watch much science fiction, you know that in the future, there’re plenty of 3D holographic displays. From Princess Leah’s distress call to the Star Trek holodeck, there’s no shortage of computers that can make realistic images. It might not be up to holodeck standards, but [freedscript] created a 3D display for an Arduino using a chopstick, a motor, some paper, and a LASER. Of course, it isn’t actually a hologram, but neither is half the stuff you see on TV (Star Trek’s holographic characters were disturbingly solid for standing waves). The display is a type of volumetric display.
We’ve all seen holograms in movies, and occasionally we see various versions of the effect in real life. The idea of having a fully three-dimensional image projected magically into space is appealing, but we haven’t quite mastered it yet. [Steven] hasn’t let that stop him, though. He’s built himself a very simple device to display a sort of hologram.
His display relies on reflections. The core of the unit is a normal flat screen LCD monitor laid on its back. The other component looks like a four-sided pyramid with the top cut off. The pyramid is made from clear plastic transparency sheets, held together with scotch tape. It’s placed on top of the LCD with the narrow end facing down.
[Steven] then used the open source Blender program to design a few 3D animations. Examples include a pterodactyl flying and an approximation of the classic Princess Leia hologram from Star Wars Episode 4. The LCD screen displays the animation from four different angles at once. The images are displayed up and onto the transparency sheet, which then get reflected to your eyes. The result is an image that looks almost as if it’s floating in space if viewed from the proper angle. If you move around the screen you can see the image from all four sides, which helps to sell the effect. Not bad for a few dollars worth of parts. Continue reading “Dead Simple Hologram Effect”→
Miniature golf is one of those pastimes that can be molded and redefined pretty much indefinitely. Like pinball machines which also come in an endless variety of flavors, each hole of a miniature golf course is a vignette with a theme designed to tie cleverly into its objective. Mini golf has come a long way from windmills and draw-bridges, and with technology thrown in the mix you end up with works of art like [Dan Rosenfeld’s] project, “Sleepwalkers” which go so far as to paint a holographic world for the player to interact with.
“Sleepwalkers” was commissioned by Urban Putt, a chain that accommodates for dense city spaces by building their courses indoors. Designed specially for its location, the hologram acts as a narrative told by tiny characters living within the walls of the historic building the golf course occupies. At a certain point during the game, a player is prompted to purposely place their ball into an opening in one of the old walls where it quickly rolls somewhere out of sight. When the player peeks through a series of holes dotted throughout the surface in order to find where it went, they discover another world sandwiched between wood beams and insulation. This becomes the setting of a short exchange with a character who the player must interact with in order to get their ball out of hock. The spectral glow and dimensionality of the wall’s inhabitants is created using a projection along with the Pepper’s Ghost illusion, a classic trick with angles and mirrors. Once the player’s hand enters into the Sleepwalker’s world through larger holes in the wall, a camera used for depth cues maps the projection to its presence. The tiny figure then uses the hand in a series of dioramas as a tool to climb on in order to reach the area where the player’s ball is trapped. After a joint effort, a linear actuator and sensor help to complete the illusion that the projected character is pushing the golf ball free into the real world where the player can then retrieve it and continue on to the next hole.
The traditional antics created by swinging pendulums and spinning windmills will always charm us, but the use of technology to take us into a new world will leave us with something more. You can see it on the faces of those interacting with [Rosenfeld’s] installation for the first time:
While we’re still a long way off from the Star Wars telepresence holographic displays, this build over on the Projects site is the closest we’ve seen yet. Even better, it can be built in a garage for not much money.
Inside the Hoverlay are a few fans and a pair of ultrasonic atomizers that turn water into an extremely fine mist. The fans pull this vapor up through the base of the display and through simple drinking straws to create a laminar sheet of water vapor. Put a projector behind this thin sheet of vapor, and you have a display, seemingly floating in mid-air.
The base of the display can be scaled up, simply by putting several units together in a line. It’s still just a prototype – future versions will improve the stability and reduce the thickness of the fog layer – but it’s still a very cool build for a custom holographic display.
[programing4fun] has been playing around with his Kinect-based 3D display and building a holographic WALL-E controllable with a Windows phone. It’s a ‘kid safe’ version of his Terminator personal assistant that has voice control and support for 3d anaglyph and shutter glasses.
When we saw [programming4fun]’s Kinect hologram setup last summer we were blown away. By tracking a user’s head with a Kinect, [programming] was able to display a 3D image using only a projector. This build was adapted into a 3D multitouch table and real life portals, so we’re glad to see [programming4fun] refining his code and coming up with some really neat builds.
In addition to robotic avatars catering to your every wish, [programming4fun] also put together a rudimentary helicopter flight simulator controlled by tilting cell phone. It’s the same DirectX 9 heli from [programming]’s original build. with the addition of Desert Strike-esque top-down graphics. This might be the future of gaming here, so we’ll keep our eyes out for similar head-tracking 3D builds.
Here’s a simple concept that will let you turn any LCD screen into a multidimensional display (translated). [Herdek] used bits of that impossible to open clear plastic packaging to construct this add-on for the smart phone seen above. Three pieces of the material have been mounted at a 45 degree angle between the screen and viewer. The material is both reflective and transparent, depending on the angle at which light hits it. This allows it to reflect the light from the screen toward the viewer, but let light from the baffles behind it pass through unimpeded. The three baffles allow the LCD to be partitioned into three different sections whose images will appear to be at different depths according to the viewer’s vantage point. After the break we’ve embedded a demonstration video, as well as the how-to that shows the construction technique for the add-on.