ADVANCED 3D VOLUMETRIC DISPLAY with variable occlusion & Variable opacity

A true 3D display has been a dream of many for years. Although various three-dimensional technologies have been developed in recent years, few are able to display real time 3D images and video from any angle in the same way an object would appear to us in the real world. The new concept is a true three-dimensional display that allows users to view moving objects from any angle with the unaided eye, simply by walking around them as you would if you were looking at real 3D objects. I have invented a with clear picture and super clear depth; it has a 360 degree horizontal and 270 degree vertical viewing angle. New 3D volumetric display is entirely different from existing 3D TVs which produce translucent images even if input is solid image. This new 3D display can provide variable occlusion (0-100%) and variable opacity (0-100%) and partial or full cross-section view and cutaway view without losing parallax or perspective.

Already since the 1940s various methods have been investigated to develop a volumetric 3D display. But technology limits made the immediate implementation impossible. Recent advances in hardware and software technology provide new chances for near-term operational concepts for certain applications. The volumetric 3D display technology will provide an important option for team tasks and tasks requiring many simultaneous views of real-time or multidimensional data.

Volumetric displays: systems that show the information in a predefined volume. In the same way that a TV screen is capable of illuminating selectively each and every one of the pixels on its surface, a volumetric display is able to do the same for all the voxels (pixels in 3D) that make up its volume. Volumetric displays create true 3D images that appear in a volume of space. You can see different parts of the image by moving your observation point as the image has vertical and horizontal parallax.

To produce volumetric images, it is necessary to create a display volume of some type within which the image may be drawn. A number of attempts to achieve this goal have been made in several past and current development efforts. Generally these attempts can be divided into two basic categories: • Swept volume displays & • Static volume displays.

There are 3 main subtypes:

Varifocal mirror: A mirrored membrane that oscillates becoming a variable focal distance mirror reflecting the image of a screen. By synchronising the image shown on the screen with the optical power of the mirror, any point of a given volume can be scanned (and illuminated). It is still quite an experimental system.

Emissive volume: a given volume filled with a medium that is able to emit light from any part of its interior as a result of an external excitation, for example by different wavelength lasers. Very experimental, the main problem is finding the appropriate substrate.

Rotating screen: a flat screen rotates at around 600 rpm. For every angular position of the screen in a predetermined set an optical system projects onto it the image of an object corresponding to the perspective associated to that angle. The final result is the 3D image of the object, viewable in 360 degrees.

Some of these rotating systems are already commercially available for a price of $45,000 , like the system called Perspecta Spatial 3D from Actuality that is the subject of the US Patent 6,183,088. Perspecta gives a resolution of over 100 Million voxels. It’s made of a spherical transparent dome that gives it a characteristic crystal ball appearance. Inside it a flat screen rotates at 730 rpm. A projector illuminates the screen successively with up to 198 images of 768x768 pixels each, showing one or the other depending on the screen’s rotating angle. Every one of the images corresponds to a slice of the object as if we cut it through a vertical axis, and it’s refreshed 24 times per second. The persistence of retinal vision converts the stack of 2D images into a sharp 3D perception of the object. The advantage of this device relies on the fact that the objects appear to be floating within the transparent dome and can be seen from any angle or position. It’s probably the closest device to the R2D2 projector of Star Wars.

Once 3D images take themselves off the computer screen without the need for goggles or special devices we will want to interact with them, touch and modify them. A new field in the human computer interface will or open.

Several static-volume volumetric 3-D displays use laser light to encourage visible radiation in a solid, liquid, or gas. For example, some researchers have relied on two-step up-conversion within a rare earth-doped material when illuminated by intersecting infrared laser beams of the appropriate frequencies.

Another technique uses a focused pulsed infrared laser (about 100 pulses per second; each lasting a nanosecond) to create balls of glowing plasma at the focal point in normal air. The focal point is directed by two moving mirrors and a sliding lens, allowing it to draw shapes in the air. Each pulse creates a popping sound, so the device crackles as it runs. Currently it can generate dots anywhere within a cubic metre. It is thought that the device could be scaled up to any size, allowing for 3D images to be generated in the sky.

New Concept 3D Display

Creating lifelike 3D volumetric images is of paramount importance to maximize realism for displays. In order to create a lifelike 3D volumetric image I have successfully developed a new concept after spending several years to research. The concept is described below. The development of my 3D Display refers to the well-known swept-volume technique, which is characterized by its comparatively simple system configuration. Compared to other approaches the new 3d display is a compact, light, and easy to transport system of modular design. As it consists of standard components, the display is also inexpensive and easy to maintain.

This is a new 3D volumetric display with clear picture and super clear depth; it has a 360 degree horizontal and 270 degree vertical viewing angle. It is entirely different from existing 3D TVs which produce translucent images even if input is solid image. This new 3D display can provide variable occlusion (0-100%) and variable opacity (0-100%) and partial or full cross-section view ability and cutaway view ability without losing parallax or perspective. The major novelty of the 3D display I invented is that it gives more clear and realistic picture. In existing designs light from front and back of an object will pass through resulting in clogged image. In my 3D display this problem was remedied by using a new individual picture cells named sphexel (spherical picture cells). This sphexel has control over the direction of light to be emitted thus solving the above problem. The sphexels provide occlusion and opacity without losing perspective or parallax. Using this we can make images of 3D display from completely solid to translucent to transparent. The new 3D volumetric display can be used for R&D of complex systems especially for medical imaging.

Image of 3D Volumetric Display Unit is given Below.

Defects in existing display systems

Images are translucent, self-transparent-->no occlusion

A pulsed laser creates points of glowing plasma in air. Here you can see that dots from back and front are viewable at any direction there is no occlusion of backside dots resulting in clogged image.

Lack of occlusion or opacity in existing volumetric displays are shown above

Another artefact is that images are not with correct perspective. Another artefact is due to the lack of vertical parallax. Just as an image on a piece of paper will appear smaller when viewed from an oblique angle, the projected image will appear to stretch vertically when the viewer changes height.

It is often claimed that volumetric displays are incapable of reconstructing scenes with viewer-position-dependent effects, such as occlusion and opacity. This is a misconception; displays whose voxels have non-isotropic radiation profiles are indeed able to depict position-dependent effects. To-date, occlusion-capable volumetric displays require two conditions: (1) the imagery is rendered and projected as a series of "views," rather than "slices," and (2) the time-varying image surface is not a uniform diffuser. For example, researchers have demonstrated spinning-screen volumetric displays with reflective and/or vertically diffuse screens whose imagery exhibits occlusion and opacity. One system (Cossairt et al, 2004; Favalora, 4 Aug. 2005) created HPO 3-D imagery with a 360-degree field of view by oblique projection onto a vertical diffuser; another (Otsuka et al, 2004) projects 24 views onto a rotating controlled-diffusion surface; and another (Tanaka et al, 2006) provides 12-view images utilizing a vertically oriented louver.

So far, the ability to reconstruct scenes with occlusion and other position-dependent effects have been at the expense of vertical parallax, in that the 3-D scene appears distorted if viewed from locations other than those the scene was generated for.

Advantages of new concept 3D Display

This new 3D display can provide variable occlusion (0-100%) and variable opacity (0-100%) and partial or full cross-section view ability and cutaway view ability without losing parallax or perspective.

Traditional 2D displays like cathode ray tubes (CRT) or liquid crystal displays (LCD), in which 3D pictures can be rendered are most popular for a wide range of applications. These systems however display the spatial information from the perspective of only one viewer.

For an ideal dynamic 3D image representation a technique should be preferred with a multiple user, all-round view capability, without requiring visual aids. It should also satisfy all depth cues such as stereo vision and motion parallax. Volumetric displays, which generate 3D images within a physical volume rather than on a stationary surface, meet most of these needs. The images are thus placed within the physical world of the observer, in comparison to virtual reality systems where the observer is placed within the virtual environment of the non-physical image space.

Spatial visualization of data can simplify or accelerate the working process. If cooperation between viewers is required, volumetric displays have significant advantages compared to common stereoscopic technologies (like virtual reality).First, the image they present is visible from a wide range of viewpoints, even permitting viewers to walk all around the display. Multiple users can communicate face-to-face and cooperate in a natural way, because no head gear has to be worn. Each user chooses his own viewpoint independently and has an individual view of the displayed data. The new display provides enhanced spatial and multidimensional analysis, planning, monitoring, simulation, communications and decision-making

The new 3D display has following features

Auto-stereoscopic - Requires no special viewing glasses.

Omnidirectional - Generates simultaneous views accommodating large numbers of viewers, allowing viewers to be situated anywhere around it, Multiple people can view in the room so the generated 3D image simultaneously from all sides and without any aids, such as shutter glasses

Multi-view - Producing a correct rendition of the light field with correct horizontal parallax and vertical perspective for any viewpoint situated at a certain distance and height around the display.

Occlusion and opacity - Imagery exhibits occlusion and opacity without losing vertical parallax. Images can be switched to self-transparent or translucent to opaque. This new 3D display can provide variable occlusion (0-100%) and variable opacity (0-100%) and partial or full cross-section view and cutaway viewwithout losing parallax or perspective.

Correct perspective - vertical parallax and perspective is maintained.

Interactive - the images can be manipulated interactively

Advantages of this 3D TV are clearer sharper pictures that are not foggy or translucent. Light weight and simple design assures Easy portability. The Real 3D TV that is more immersive than any other visualization facility. It has 360 degree of viewing angle (inward direction) so it produces a complete real life like images. And can change image from Solid, Translucent or transparent. This 3D TV can be used for medical, engineering, entertainment, aerospace applications etc. There's no better way for teams of technical and creative professionals to engage in interactive, real-time engineering and design review, data analysis, critical training, presentation, virtual prototyping or command-and-control operations. The real 3d TV facility delivers the highest levels of realism, and performance available today. You and your colleagues are immersed in your virtual environments natural 3d images, so you can explore, understand, and communicate about your data in ways not possible in the physical world. This approach helps you arrive at better decisions in less time, providing enormous cost savings while enhancing productivity. You'll gain insight and reach your goals with greater speed, efficiency, and flexibility than ever before. Another model of 3D TV is again a semi mechanical one. This is how it works, a circular plate of LED array moves up and down 25 times in a second. This gives an illusion of cylindrical space of picture, when viewed from top or at an angle; viewer gets an illusion of 3D moving picture. This 3D TV has a huge potential in virtual prototyping, where motions of mechanisms (with transparent or opaque material assigned to the model) can be analysed in real 3D world by a group of people, this is not possible in rapid prototyping machines. Animations of FEA can also be analysed. Greatest advantage over existing stereo viewing is that , while watching 3D image you can lean sideward and watch image in that viewing angle. This is very much natural or the way what people expect. Another advantage is that no eyewear is needed for this 3DTV. Software for creating 3D images from 2D natural images (images from multiple cameras) is already available. This software is used in reality centres of US defence department

Spherical Picture Cells (Sphexel)

Instead of existing 3D TVs voxels we can use sphexels (spherical picture cells) to view full colour pictures. In a sphexel pixels are arranged in a spherical manner around a sphere as shown in figure. These sphexels are arranged linearly along the rods of 3D TV. In a sphexel each pixel is a full colour light emitter like LED. Advantage of sphexel is that light is emitted to desired direction only. This way occlusion and opacity are achieved without losing perspective or parallax. (for example if the image is a head the sphexel that emits the light of front side of head does not emit light to backward direction. similarly the sphexel that emits light of back side of head does not emit light into front side of head. so we get a clearer sharper picture. i.e. no merging of front side to back side takes place)

Working Procedure

Every frame, approximately 100 planar cross-sections of a 3-D volume are displayed on the LEDs in this volumetric 3-D display. For example, the 3-D scene is computationally decomposed into a series of "slices," which can be rectangular, disc-shaped, or helical cross-sectioned, whereupon they are displayed from a display surface undergoing motion. The image on the 2D surface (created by LEDs embedded in the surface) changes as the surface rotates. Due to the persistence of vision humans perceive a volume of light. The light-scattering characteristic of LED enclosures assures that it is visible from angles it is supposed to be.

Essence of the system is an planar surface where sphexels are arranged on it or helically arranged rods (like DNA molecules) and Sphexels arranged on each rods. The planar surface or rods are rotated at 1800 rpm and Sphexels are illuminated intermittently. Since rods are rotating we will not see the rods, we only see the part of the Spexels that is being illuminated for a fraction of a second. (Just like we can see rotating fan's leaves in fluorescent light but not in daylight) If input is programmed for an image or movie, we can view movie or picture on the rods.

Theory

Just like scanning line (1D) create 2D image scanning a plane (2D) creates a 3D image. You can see leaves of a rotating fan under a flickering light but not in continuous light. In my design the sphexel emits light in desired direction for a fraction of a second. So we can view the light emitting sphexels, not the other rotating sphexels. . The screen illuminates successively with up to 210 images of 640x640 pixels each, showing one or the other depending on the screen’s rotating angle. Every one of the images corresponds to a slice of the object as if we cut it through a vertical axis, and it’s refreshed 24 times per second. The persistence of retinal vision converts the stack of 2D images into a sharp 3D perception of the object.

Uses

The new 3d display can aid in the treatment of cancer patients receiving radiation therapy. The 3D technology enables doctors to clearly observe the path of focused radiation, thereby minimizing damage to nearby critical organs. , if a doctor wants to view a CT scan of a patient's heart, the new display system can display it in 3d. This new display can load 3D medical data, integrate it with existing (e.g., Philips) therapy systems, and then review and change treatment. CAT scan and NMR images displayed with a volumetric system will show the actual shapes of organs or tumours for the doctor making disease processes easier to visualise.

The new 3d display can also help simulate the 3D structure of complex molecules useful to both chemists and biologists, as well as in drug development. And this new 3d display can be used in gas and oil industry as well as the military, which would be interested in new display devices ability to display 3D topography.

Another application for this type of display are air traffic control and surveillance. The volumetric display will improve the safety of air traffic by allowing the controller to see a picture of the controlled area and the relationships of the planes in three dimensions without any aberrations. The volumetric display system allows the viewer to use their full optical senses. A true 3D representation is air traffic control on a flat radar display a three-dimensional space cannot be shown satisfactorily. The missing third dimension, in this case the flight altitude, must be indicated by figures. As a consequence a controller has to constantly observe all aircraft on the radar screen to form a mental image of the actual airspace situation. After an interruption, his mental image is disturbed and he needs some time for readjustment. A true 3D volume display should be designed to complement state-of-the-art 2D radar displays for an improved performance needed on safety-critical observation tasks.

Proposed Display for air traffic visualization/surveillance is shown below:

A volumetric display would help to interpret wire-frame structures because the depth cues accommodation, convergence, stereoscopic vision and the laws of perspective are satisfied. Thus a volumetric display is a useful complement to common CAD tools reducing prototyping costs.

Potential applications are:

· Scientific visualization

o Projection of multi-dimensional, complex data structures and graphs.

· Air surveillance / air traffic control

o 3D visualization of a typical air traffic scenario close to an airport.

· Medicine (such as computer tomography)

o Display of a human skeleton and organs in three dimensions.

· Chemistry / Physics/pharmacy:

o Visualization and analysis of molecular structures.

· Fluid Dynamics

• Visualization of streamlines in 3D.

· CAD / Robotics

o Projection of a 3D wireframe graphic of an aircraft structure.

· Education

• Working teams from different places all over the world can interactively discuss and manipulate a spatial design.

· Arts / Entertainment / Advertising

o As an interactive 3D play-console.

o Interactive 3D internet communication tool.

Mass-Market penetration plan for real 3D TV

Initially low cost 3DTV using voxels will be used in large 3D billboards at the junctions to small house hold gadgets like support for tea tables in living rooms. This will help in public awareness, return of investment in the research and above all boosts in brand equity. in large 3D billboards animations of 3D wire frame models will be used for the advertisement. This will be far better than current laser shows. In house hold gadgets animations of images of family members, vehicles, aircrafts and animals or cartoons with a story or theme will be used to entertain guests and kids etc. And then it can be used as large 3D Arena (Indoor) with cylindrical outside 2D video walls; inside this cylinder, 3D Display is placed. 3d arena is a large indoor stadium where people are seated in a circular gallery and a large 3D volumetric display is placed in the middle as shown in picture below. In this 3D Arena people can watch sports, movies and interesting documentaries like IMAX.

Note: Sphexels are future proof, they must be used in future 3D TV’s with solid volume transparent organic LEDs. 3D TVs with air as medium don’t have control over direction of emitting light from each voxels.

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inventor: Diji N J

Nedunghayil

Vennala P.O.

Ernakulam

Kerala

India

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