C H A P T E R  9

Volumetric Display Techniques

In this chapter, you will become familiar with the various techniques for the volumetric display of visual imagery. Unlike a traditional 2D screen, or even the newest glasses-based stereoscopic 3D TVs and movie theatre experiences, volumetric technologies providethe viewer with a feeling of “holographic” imagery with varying degrees of motion parallax based on the technique used to recreate a display in natural 3D space. Motion parallax describes the ability to perceive depth based on the movement of the observer relative to multiple stationary objects against a background. Believe it or not, many people cannot actually perceive the 3D effect from stereo glasses because their brains lack full stereovision development. How come these people aren't bumping into things? It's because every slight movement of your head reveals the depth of your surroundings. This feature, not yet available in any mass market 3D solution, is what sets this novel approach apart from glasses-based experiences.

Perhaps the most well-known practical example of a volumetric display from the realm of science fiction is from the original Star Wars movie, when R2D2 displays a recording of Princess Leia telling Obi WanKinobe he's her only hope. Depth-sensing photographic technology, such as the Kinect, effectively captures “holographic”or volumetric video recordings, but doesn't provide a way to display them back into volumetric 3D space. Volumetric displays are the key to projecting these “holographic” experiences back into the dimensionality of everyday life. For the most part still on the edge of research and prohibitively priced for consumers to experience at home, these displays won't make it into your livingroom this year—but the pace of technology's progress takes unexpected leaps, as the Kinect has shown us.

This chapter will cover the full spectrum of novel display types, including those that strictly qualify as volumetric displays and many that do not. It will cover those that contain key aspects, such as motion parallax and multiple views on a screen, and some that have none of those qualities yet receive recognition, as the public erroneously refers to them as “holographic” because their imagery hangs in the air. This is an introduction to display technology that many are unfamiliar with, as little up-to-date information on the topic has been collected on the internet. These innovative approaches will likely be seen more in the future, perhaps in combination, to satisfy the demands of a public having been primed by the Kinect's volumetric camera and who will come to expect more than just a 2D screen for truly immersive experiences.

Static Volume Displays

If you've been through any major American mall or tourist area in the past couple of years, you've likely seen the novelty service that takes a 3D portrait photo, which then gets etched into a clear plastic prism (Figure 9-1), a process known as sub-surface laser engraving. While this isn't a volumetric display that can be updated, it provides a reference point for understanding the first class of displays known as static volume displays.

Figure 9-1. A Sub-Surface Laser Engraving. Image courtesy LooxisFL.com

For a volumetric display that can come to life and change like video in realtime, we'll need to look at ways to turn colored light on and off for a volume of interest instead of simply having an image statically etched in place. A straightforward way to accomplish this is through the use of LEDs in a cube formation, wherein each single Light Emitting Diode acts as a voxel. Figure 9-2 shows such a device. It is built by eight-year-old Joey Hudy who is the driving force behind the site “Look What Joey's Making” at http://lwjm.us/. Joey builds the LED display shown in Figure 9-2 for sale. Visit his website to order yours today.

Figure 9-2. Arduino shield for a 3 × 3 × 3 LED display by eighth grader, Joey Hudy, courtesy of lwjm.us

One of the largest commercially available displays of this type has an array of 66×48×24 LED lights and is created by Seekway (http://seekway.com.cn). That's 76,032 individual lights that need to be wired up in a circuit and individually addressed with a microprocessor. The unit is roughly 6 feet tall, 1.5 feet deep and 3 feet wide. It costs many thousands of dollars.

Projection onto Static Volumes

A very clever technique to overcome the need to electrically wire up individual lights to a gridded out cube is to simply project light onto a reflective material at that volume of interest in space. Albert Hwang, Matt Parker, and Elliot Woods created Lumarca, an open source design project (Figure 9-3), to accomplish this through the hanging of hundreds of strings in a very special way so that a projector can be pointed into the mesh with extraordinary results. With custom software for calibration and very precise positioning of an SVGA (1024 × 768) projector into the string array, each string can be individually addressed with light, regardless of where it resides in space—at the front of the volume, at the back, and anywhere in between and side to side. Every string must be carefully placed so as not to obscure the projector beam from hitting another string behind it.

The details of how to construct one of these on your own for less than US$100 are on the project's website at http://madparker.com/lumarca/construction. At the New York MakerFaire 2011, the team debuted a pico projector- sized kit, roughly 1 foot cubed. Taking this miniaturization further, could “strings” or dots 3D laser etched into a small plastic prism with a pocket projector reproduce this type of display in a solid state medium? Researchers at Columbia have taken a step in this direction with their work on projected passive optical scattering (http://www.cs.columbia.edu/CAVE/projects/3d_display/). There's still much to research and develop with regard to volumetric 3D displays, so mixing and matching these techniques could lead to innovations previously undiscovered. Onward pioneers!

Figure 9-3. Lumarca volumetric display with projection onto hanging strings. Photo by Jeff Howard

Swept Volume Displays

Swept volume volumetric displays are in many ways the “traditional” volumetric display. Patent applications for these devices go back to the 1950s and 1960s but we only began to see actual implementation in the last couple of decades. A swept volume display takes a single light emitting 2D slice of a volume and, through a mechanism that rapidly moves the location of the slice and its content in context with the space it is pushing through, uses the persistence of vision optical effect to imprint a volumetric 3D image hanging in space.

In 1988, the New York Hall of Science spent US$40,000 to construct a volumetric 3D display that could interactively depict “The Quantum Atom.” With the reciprocating mechanical motion of a platter painted with light from a computer controlled oscilloscope, the individual slices of a solid moving object were carved into space inside a cylinder, which allowed audiences to walk 360 degrees around the interactive electronic 3D image. Alan Jackson, the designer of that display, has launched a new initiative to get affordably-priced units that utilize the same reciprocating motion swept volume technique into the hands of developers, using modern hardware and open source software.

Alan's VoxieBox (http://voxiebox.com) will be available in kit or preassembled form starting in 2012. Similar to the OpenNI initiative of Primesense, the VoxieBox will promote an open source framework being developed for volumetric displays at OpenVoxel.org to attract a developer community that can take advantage of these devices' unique capabilities. While the Kinect has done so much to make technology accessibility for development around 3D capture, the VoxieBox and other devices that the OpenVoxel framework will support aspire to do the same for volumetric 3D displays. Unlike the proprietary commercial devices and research projects that debuted, and then failed to gather momentum in the public eye, efforts leveraging the passion of open source innovators have a chance for success.

One of those research projects was from the Institute for Creative Technologies at the University of Southern California. This project relied on a swept volume mechanism to enable their “Interactive 360º Light Field Display” (Figure 9-5). In this design, a projector is positioned pointing down from above the spinning mirror. This direct approach could be the basis for reproducing the desired effect in a controlled environment—perhaps an art, museum, or retail installation—for a more self-contained apparatus that doesn't have room for a projector at a distance. More information can be found about this system at http://gl.ict.usc.edu/Research/3DDisplay/.

In 2002, Actuality Systems introduced a product that used a swept volume technique similar to the rotating mirror system described by the Institute for Creative Technologies. Their device, Perspecta (Figure 9-4), cost roughly $30,000 and used a sophisticated series of optics under the rotating screen to make the device significantly more compact. Because the projection wasn't from above, a viewer could place their hand on top of the glass screen without interrupting the image display. Perspecta devices were marketed to the medical industry to visualize the volumetric imagery produced from MRI scanners. One drawback to systems that rely on physical motion to sweep out imagery is that parts can break down and need more frequent replacement than solid state systems and the persistence of vision effect can be interrupted from vibrations that disturb the intended path of the screen through space. Therefore, such systems would be unsuitable for mobile applications inside vehicles and unacceptable in environments exposed to the rumble of a spinning machine. Perhaps due to difficulty in gaining acceptance for such a unique product, Actuality Systems closed down in 2009 yet its engineers are available for consulting from opticsforhire.com.

Figure 9-4. Perspecta Volumetric Display by Actuality Systems, Inc. Images courtesy OpticsForHire.com

One of the main drawbacks of these swept volume systems is the maintenance of the device with moving parts. LightSpace Technologies created a remarkable approach to address this problem with the DepthCube. By rapidly cycling a projected image onto one of 20 vertically stacked liquid crystal coated plates, a volume of slices that has depth is built up. The LCD plates remain opaque until electric current is applied, at which point they become transparent. Utilizing the DepthCube design, with only one of the 20 plates opaque at a time, a projector can present the correct image slice onto that plate from the full volume stack. With everything synced up and running very fast, persistence of vision blends the image slice stack into a cohesive volumetric image. See the DepthCube in action at http://youtu.be/RAasdH10Irg.

Other than in patent filings and academic papers, there is very little information online about how to construct your own swept volume display. This will change as more attention is drawn to their unique abilities. We need to see a greater community brought together with a shared interest in seeing this technology reach the mainstream. Until then, this how-to-guide for constructing a spinning swept volume with LED lights gives an idea of what is involved: http://bit.ly/makevolumedisplay.

Should you require a projector based image generator for high resolution displays where LED begins to show its limits, the DLP developer kits from Texas Instruments (http://bit.ly/dlpdevkits) provide a strong base to build upon. Texas Instruments' Digital Light Processing with a Digital Micromirror Device, which sells for $350, with the DLP Pico Projector Development Kit can run at 1,440 frames per second in one color, is smaller than a deck of cards, and produces an image brightness of 7 lumen, making it ideal for very short throw installations. At its native 480 × 320, you'll want to keep the projected image small to make for the densest image quality. For $3,500 the DLP LightCommander offers a more modular design—about the size of a fog machine—that can go up to 5,000 frames per second in monochrome binary pattern mode and supply 200 lumens-worth of light out of a Nikon f-mount interchangeable lens. Its native resolution is 1024 × 768. The DLP Discovery 4100 Kit costs upwards of US$8.000 and offers resolutions of HD 1080p (1920 ×1080), along with much more advanced feature sets.

Pepper's Ghost-Based Displays

While swept volume techniques can produce true volumetric 3D imagery that hangs in the air, providinga unique perspective from every angle, the price tag for such systems are prohibitively high, especially for displays that are relatively small. On the other end of the spectrum and dating back to the 1860s, is a technique that was developed as a theatrical special effect, which can scale to very large environments and which has been used to provide a convincing “in air” visual effect. John Henry Pepper's illusion was originally used to magically display transparent ghosts on stage for a performance of Charles Dickens's A Haunted Man. Now referred to as “Pepper's Ghost” (Figure 9-5), this optical illusion relies on the reflection of light from an obscured source onto a transparent film or glass plate where the image is seen to be hanging in space. This same principle is what makes teleprompters and heads-up displays work. Variations on this technique are behind many “holographic” imagery effects and displays.

Figure 9-5. Illustration of the “Pepper's Ghost” illusion by Professor John Henry Pepper at London's Royal Polytechnic, 1881

A number of commercial solutions are available to bring this type of display to life on both large and small scales. Musion Eyeliner 3D (http://eyeliner3d.com) and Arena 3D Industrial Illusion (http://arena3d.com) sell and lease systems that are used for trade exhibits and major entertainment productions. Teleportec (www.teleportec.com/) sells a smaller system tailored to telepresence, which can place a remotely conferenced person behind a podium for a speech or at a board table for a meeting.

Alexander McQueen received much fanfare for his use of a Pepper's Ghost-based illusion for his Widows of Culloden, autumn/winter 2006/2007 fashion show, in which Kate Moss materialized and floated above the stage. Prerecorded video of the model, shot from four different angles, 90 degrees apart, was reflected from hidden screens suspended above four panels of glass that formed a transparent pyramid shape.

A number of companies have created smaller self-contained Pepper's Ghost-based display cases that work well for showcasing a hovering or transparent product—even mixing digital video and a real physical object into the same display area. Figure 9-6 shows a simple three-sided Pepper's Ghost design using a MacBook. This design was created by Ujjval Panchal. You can read more at his blog:
http://blog.ujjvalpanchal.com/3d-holographic-display-prototype-1/.

Figure 9-6. Three-pane Pepper's Ghost display with MacBook. Photo courtesy Ujjval Panchal

HoloCube (www.holocube.eu/) has a number of simple and pleasing box-shaped designs for viewing in one direction. RealFiction (www.realfiction.com/) and Vizoo (www.vizoo.com/) sell pyramid-shaped systems, working off an arrangement similar to the Alexander McQueen show, that allow viewing from 180 to 360 degrees with either three or four separate channels of video corresponding to different angles.

An innovative use of the Pepper's Ghost technique is to separate a single 2D display or projection into multiple Pepper's Ghost layers, which can be stacked up to recreate a foreground, middle ground, and background. A prototype accessory for the iPhone was created on this principle, called i3dg (Figure 9-7), and at lost word was slated to go into production early in 2012. You can see the display in action in this video—http://youtu.be/JnGPtVNmtvI—and learn more at http://i3dg.mobi.

Figure 9-7. The i3Dg accessory for iPhone utilizes three panes of plastic to create a multi-depth experience, utilizing the principle of Pepper's Ghost. Image courtesy i3Dg

The original mock-up for this design came from using plastic CD cases; others online have successfully recreated this effect using various materials. On a larger scale, with a flatscreen TV or uniquely shaped projection surface, this technique could be employed to create a very eye-catching experience with a real sense of depth and motion parallax with the right content or application.

Multi View Autostereoscopic Flatscreens

Of all the technologies described in this chapter, multiview autostereoscopic displays are the most mature and accessible technology. Available from a variety of specialized providers, they can be used with existing development tools at a cost that is not as prohibitive as the more researched and industrial level technologies. The market size is currently about 2–4 thousand autostereoscopic 3D displays per year for digital signage applications, which keeps the price tag for these items around US$5,000. Each display requires a significant amount of resources to carefully produce—from custom manufacturing precision slanted lenticular sheets for every model of LCD to the “clean room” environment needed to adhere the multiview layer to the screen. Additionally, the custom content production and hardware requirements can be substantial for delivering enough views to the screens to make the viewing experience truly eye popping without causing eye strain. Mainstream consumer adoption of such screens would drive the cost down considerably—just as Kinect did for the depth-sensing volumetric camera market.

Displays are available from a variety of manufacturers. Magnetic3D (http://magnetic3d.com), 3DFusion (http://3dfusion.com), and Exceptional3D (http://exceptional3d.com) are all based in New York and offer nine-view displays at varying levels of size and quality. Alioscopy (http://alioscopyusa.com / http://alioscopy.com), uses an eight-view display technique. Lower-end displays can be found with four and five views, and on the high end, Dimenco (www.dimenco.eu), founded by a team that worked on autostereoscopic screens at Philips, boasts a twenty-eight-view system. Dimenco's approach relies on 2D + depth map source material and a dedicated hardware “rendering box,” which limits its potential to use native multiview content. Magnetic3D's nine-view allows a center channel to act as a reference image with four views to each the left and right for peering around an object. In a slated lenticular design, finding the right compromise between the number of views to give a good motion parallex and not packing so many views in that there is ghosting or cross-talk between the layers of pixels underneath is a careful balance.

As with any of the volumetric displays discussed in this chapter, somewhere along the line, you'll have to figure out how you will optimize multiple views of your application or content to match the physical properties of a display. These screens are at their best when the viewer can feel depth that both drops behind the screen and protrudes out from it. Thomas J. Zerega, founder of Magnetic3D, suggests that content and application developers can design experiences that utilize these displays to their limits, enabling “True Volumetric Perception” by following best practices in how content is prepared. When visual assets protruding out from the plane of the screen get cut off by the LCD's border edges, a “window violation” that disturbs the perception of depth is produced. To avoid this experience, programmers can create in-app physics that avoid such glitches by design. You can use this effect to your advantage by letterboxing the display area; that is, placing a black border around the content on the screen. This way, when an object is meant to come out from the screen, it can break the digital letterboxing—to a great popping effect—without getting cut off by the hard physical “boxing” of the display edge.

Laser Plasma Emission Displays

If the idea of producing images hanging in air instead of stuck to a screen is what you are after—pulsed laser's crackling light in free space is going to excite you. Japan's National Institute of Advanced Industrial Science and Technology (http://bit.ly/plasmaemission) has partnered with Keio University and Burton Inc. to push the edge of using lasers to light up air molecules in a true volumetric display that works without the need for a generated medium such as mist.

The mechanism by which this type of display works is fascinating on two levels. First, it shows a real time demonstration of a dynamic display that matches the variable point abilities of the static plastic etching laser noted at the beginning of thischapter. This is great, because the mechanism isn't bound by a set grid of voxels that it must adhere to. This is in contrast to other static or swept displays, which are locked into the boundaries of pixels or LEDs.

The second level of interest is the inspiration to apply the optical tricks leveraged to focus the laser beam to other types of display optics. The use of a diffusion lens moving in the z-axis and a second optic modulating in the x and y plane might have application with the other approaches outlined in this chapter. As more interest gravitates towards the aspiration of true volumetric displays, we're bound to see a mixing and matching of these techniques to bring about more breakthroughs. Stay tuned to Burton, Inc (http://burton-jp.com) for more developments with this technology. The latest demonstration of their display can show 50,000 voxel points in space per second. Check out the videos at http://youtu.be/EndNwMBEiVU and http://youtu.be/KfVS-npfVuY to see it in action.

Free-space Aerosol Displays

Molecules that float in air—sprayed water, dense fog, and fine mist—can be used as a medium for projection with stunning results. The commercial products that fall into this category tend to be based on 2D source material, so their degree of true volumetricness is owing to the illusion that a borderless volume of space contains a floating slice of imagery without the traditional boundaries of a screen. However, in custom engineered setups with multiple sources of imagery and clever manipulations of in-air particles, anything is possible.

The market for this type of display is often stage shows or big events with an array of unique lighting of which an in-air display is one part of the larger experience. At the World's Fair EXPO 2005 in Japan, I witnessed a remarkable use of this technique in Robert Wilson's “In the Evening at Koi Pond”. This system combined projections on giant solid objects floating in a pond with multiple projections in fountain mist that floated hundreds of feet in the air. The use of free space projection was reserved for moments when a certain character would appear or other accents to the main choreography took place. This gave those moments jaw-dropping impact.Therefore in an installation or performance situation, consider theuse of the techniques described in this chapter in combination for best effect.

The IO2 Heliodisplay

The IO2 Heliodisplay (www.io2technology.com) uses ambient air passed through a series of thermal controlled metal plates to create a sheet of ultrafine invisible articles that jet out from the unit. At less than 10 microns, the semi-invisible atomized water particles are similar to human breath when exhaled. Therefore, there is no visible fog or heavy moisture from this unique design in contrast to other approaches. Used in combination with a high-powered 4500 lumen projector, optimized for a rear projection setup and this air stream, a visible image can be seen to hang in the air a distance from the unit (Figure 9-8). The unit costsUS $48,000 forthe base model, and US$68,000 for an interactive unit.

Figure 9-8. Heliodisplay embedded in a table and various orientation options. Image i2o Technologies

An upright configuration, which can be hidden in a wall, casts the air stream out horizontally and can be tall enough to project an image of a life-sized human. A table-mounted unit sends the air stream up vertically with the effect of an image floating above the surface. The unit can also be hung upside down and send the screen out in virtually any direction on special order. The trick is to design content with a black background and hide all of the physical components, as well as the projector and the heliodisplay unit, so all that is seen is the floating imagery. The system does not work with a front projection or short throw projector, so you'll need to configure this in such a way that you can place the projector about five feet behind it. A small tank filled with tap water allows the unit to run for a couple of days to a week, depending on its settings; a special disk needs to be replaced every sixmonths to a year. It can even be used outdoors—but you'll need an environment without too much wind, as windwill distort the image. Speaking of distortion, don't expect this to look as clear and crisp as a flatscreen normal projection TV. If you look closely at the product images, you can see that a streaking effect is noticeable. As with any technology, it's best to consider how to leverage limitations in a way that makes them look like advantages, perhaps working the streaks and wavy flow of the screen into an aesthetic that fits the application.

The FogScreen Display

If you don't need something up close and personal, and instead want to go larger than life for the stage—look no further than the FogScreen (fogscreen.com) from Finland (Figure 9-9). Their units use a laminar airflow process to create a thin screen made of water in the form of visible fog, and ultrasonic waves. Their entry-level unit, the FogScreen EZ, is priced under US $30,000 and unlike the Heliodisplay, is available to rent worldwide. The FogScreen Pro can be connected in series for variable scale installations and is available for order by the meter starting at US $33,000 for one meter, US $100,000 for four meters, and US $175,000 for eight meters, with a variety of prices in between.

Figure 9-9. FogScreen projections at E3 conference.Photo by wili_hybrid.

The FogScreen gets a great deal of use in stage lighting and event displays, whereas the i2o unit is more suited for intimate settings at a smaller scale. In contrast to the floor- and wall-mounted Heliodisplay, the Fogscreen works in one orientation—from above. This allows the unit to be hidden out of the way along with its projector attached to the ceiling. Because the light scatters rather than reflects from the particles in the air, the FogScreen must also be used in a rear projection capacity. This property could be used to your advantage, as some researchers have experimented with two projectors pointing at either side of the screen to show a different image, giving a sense of 3D. The FogScreen has controls to change the level of opacity in the screen. That means you can use it for a “reveal” effect of someone coming out from behind a curtain of projection, or make it transparent enough to appear floating in air with no edges.

One especially promising technique relies on the fact that dispersion of light through fog has directionality. At the Interaction 2011 conference, researchers from Osaka University used a three-projector setup pointed at a cylinder of fog to demonstrate different images of a 3D object based on different angles of view, satisfying motion parallax. Remarkable video of this innovative technique can be seen at http://youtu.be/yzIeiyzRLCw. The use of multiple projectors to satisfy multiple views into a scene is the basis for light field-based displays.

Projected Light Field Arrays

An area of volumetric imaging currently receiving much attention relates to the use of an array of projectors to recreate multiple views of a scene onto a diffused light filter. The general idea is that, the more projectors you can add at more angles, the better you can recreate the original light field of a 3D scene. Therefore, when the viewer observes the scene through a special diffuser film, the movement of the viewer's head through the viewing angle will stimulate the motion parallax required to provide the sensation of viewing a 3D scene. With the advent of low cost projectors, including pico class devices of diminutive size, this approach is much more financially feasible then it would have been only a few years ago.

The projected light field approach is applied to produce a novel effect in fVisiOn—floating 3D vision on the table—a research project from Shunsuke Yoshida at Japan's National Institute of Information and Communications Technology. The intent of this project is to create a display that doesn't interfere with the workspace of a table, but instead allows for the comingling of real 3D objects and virtual ones.

Instead of implementing a standard planar sheet to combine the projected light into a cohesive 3D image, the fVisiOn approach relies on a cone shaped screen. As seen in Figure 9-10, the display is made up of an array of pico projectors all pointed inward in a circle onto the cone. The white dots of light visible in the upper right hand image show the densely packed ring of projectors. Two layers of filtered material are placed on top of the cone to increase the contrast in the image.

Figure 9-10. The fVisiOn display deconstructed. Upper left shows the cone shaped diffuser and pico projector at one angle; upper right shows dozens of projectors in place, appearing as dots of light; lower left and right show two layers of filters that increase the contrast in the image to produce a floating digital object.

While the fVisiOn provides insight into how light field displays can be used on a small scale, many are eager to know how volumetric 3D experiences will scale up to bring voxies to the big screen of a theatre. The answers may lie in a series of innovation initiatives spearheaded by the European Union. Three projects: HOLOVISION (www.holovisionproject.org), OSIRIS (www.osiris-project.eu), and COHERENT (www.coherentproject.org) were established to position European countries and companies as the leading pioneers of holographic media capture, transmission, and display. The primary integrator for these technologies is a Hungarian company called Holographika (www.holografika.com/).

Through the use of roughly 100 projectors focused on a diffusion screen, Holographika's displays recreate a light field to provide a discreet view into a scene, dependent on each viewer's position with regard to the screen. This technique is similar to the efforts from Osaka University researchers with fog, the difference being, this company now has units in production ready to be rented or purchased. It's fitting that a Hungarian company achieved this marvel, as it was, in fact, a Hungarian scientist who invented the field of holography.

While the products from Holographika are not priced for consumers, ranging from US $45,000–150,000, they've set the bar very high and will provide a reference spec by which to judge future solutions. For home and office usage, the rear projection models appear visually similar to early widescreen TVs before plasma and LCD. In order to pack all the projectors inside, there needs to be enough depth to bounce the images onto the screen. However, the more breathtaking innovation lies in the front projected solution for large scale theatre environments(Figure 9-11).

Figure 9-11. HoloVizio C80 by Holografika

The HoloVizio C80 has ushered in the age of volumetric 3D movie theatres, what people may one day call the voxies for short.This isn't science fiction. The C80 unit is currently being demonstrated in trade shows around the world. Where traditional movie theatres have one projector, or perhaps two for stereoscopic 3D, Holographika's technique employs upwards of 80 projectors. Presently, the maximum-sized screen is around 140" wide—large enough for a small indie theatre. Now, we just need a new generation of storytellers to kick start the voxie business with volumetric motion pictures that take advantage of this disruptive innovation. Which would you pay more for—a night out at the movies or the voxies?