The Heart of Virtual Holography
There are a number of drawbacks to traditional two-dimensional environments. In 2D, images appear flat and only offer one perspective. In 3D, images have depth and offer multiple perspectives. A true virtual-holographic representation overcomes the limitations of even the very highest resolution 2D flat screen display. Part of the benefit of a 3D environment is the comfort of the experience; as in the real world, there are no conflicting cues and no need to envision how a 2D projection will appear in three dimensions — with 3D, you see it and operate with it exactly as it is.
The challenge with current 3D technologies is ensuring user comfort and natural ease of use when manipulating objects in 3D. To be realistic, 3D simulations should appear 100-percent solid in open space, with full color and high resolution, as if they were real physical objects.
Today, real 3D visualization is experienced through several components of a complex system: an interactive display, head tracking to monitor the user’s real-time movement, and a stylus to interact with 3D objects. To create the 3D effect, the display alternates left- and right-eye images filtered by polarized glasses. The glasses allow only the intended image to reach each eye and provide a reference point for head tracking, so one can move and look at an object from different angles and perspectives. The stylus beam allows the user to select and grasp the object, which appears free floating in space, in much the way that a mouse allows two-dimensional manipulation of flat drawings (see Figure 1). The object can appear in front of or behind the display. This experience lies at the heart of virtual holography.
3D experiences have the potential to move our physical world into a sensoryrich virtual one that anyone can naturally and intuitively navigate, significantly advancing the way we solve problems, learn, teach, and communicate. The user can manipulate any object with the same fluidity that he or she would in the real world. In the real world, if one needs to grasp an object behind another object, the actions seem obvious and natural; the same applies in 3D virtual holography. Consider three examples:
a. Designing a vehicle, such as a car, robotic explorer, or space rover: Normally this would require many man-hours of design and mockup based on two-dimensional projections. In a 3D virtual-holographic environment, it is possible to draw, select, and assemble all of the individual parts just as if they were built by hand.
b. Examining a MRI: Conventional technology requires that you scroll through slides or slices of the images, imagining the anatomy in 3D. In a virtual-holographic environment, anatomy is visible in 3D, and an organ can be lifted, brought forward, turned around, and examined in every detail.
c. Designing a monitor for computer or entertainment applications, an example of industrial design: In a 3D virtual-holographic environment, data is entered into CAD programs, then the monitor is sculpted and manipulated in all three dimensions simultaneously, all as if physically handling the object.
As a corresponding example, volumetric data may be viewed and analyzed in a 3D virtual-holographic environment in a way that offers intuitive insights otherwise much more difficult to realize with traditional 2D projections of three-dimensional information.
How it Works
Much of 3D virtualization technology is still behind the scenes in development, though some concepts about the interworking can be revealed. First, stereoscopic 3D imaging simulates a three-dimensional scene in two dimensions using monocular cues, such as perspective, highlights, shadows, texture, and other rendering techniques. The resulting 2D image could be referred to as a monoscopic 3D image or simply as a “3D” image.