seminar series: stereo systems: overview adapted from: “stereo & 3d display technologies”...

Seminar Series:

Stereo Systems: Overview adapted from:

“Stereo & 3D Display Technologies”Prof. David McAllister - Date: Wednesday 19th October 2005

Presenters: Erica Calogero, Alastair Moore, Mojtaba Bahrami

Virtual Environments – VIVE007/4C76 - Dr. A. Steed

1. Introduction

1.1 Depth Cues1.2 A Technology Taxonomy 1.3 Stereo Pairs

2. Display Technology Overview

2.1 Separating Left and Right Eye Views 2.2 Cross Talk 2.3 Field Sequential Techniques 2.4 Time-Parallel Techniques

Erica Calogero

Stereo & 3D Display Technologies Introduction

1.1. A Technology Taxonomy

Terminology –

Stereo window/ stereo planeInterocular distanceHomologousVertical disparity/ parallax (always = 0)Wall-eyedPseudo stereoConvergenceAccomodation

Stereo & 3D Display Technologies Introduction A Technology Taxonomy

3D displays fit into one of 3 categories:

• Stereo pair – fixed accomodation, virtual• Holographic - dynamic accomodation, virtual • Volumetric/ Multiplanar – dynamic accomodation, solid

Stereo Pair Technologies:

• Distribute L & R views of a scene to the viewer• Special viewing devices are often needed to direct

the appropriate view to the correct eye • If no special device is needed, then the technology is called

autostereoscopic. i.e. hard copy devices.

1.2. Stereo Pairs

Stereo & 3D Display Technologies Introduction Stereo Pairs

Stereo & 3D Display Technologies Display Technologies Overview

2. Display Technologies OverviewSeparating Left & Right Eye Views• Cross Talk

• Ghosting/ blurring that occurs when both eyes can see the images intended for the other eye.

• Field Sequential Techniques –• One image is presented to the left eye while the right eye is block and vice versa. e.g. the CAVE.

• Time Parallel Techniques – • Both images are presented at the same time and eye is directed to the correct image by different means. e.g. HMDs, View Master, red & green glasses.

Stereo & 3D Display Technologies3D Devices

3. 3D Devices: Viewing Devices Required

1. ( Hardcopy )2. Field Sequential Devices 3. Pulfrich Technique 4. FakeSpace PUSH Display 5. Work Bench Displays 6. VREX Micropolarizers

Field-Sequential / Time multiplexed Methods

Stereo & 3D Display Technologies3D Devices Field-Sequential Devices

Active Glasses – eg. CrystalEyes system

Advantages: high dynamic range >1000:1

no ghosting/double image <32%

Disadvantages: high frame rate required power supply synchronisation fragil

Stereo & 3D Display Technologies3D Devices Active Glasses

http://astronomy.swin.edu.au

Stereo & 3D Display Technologies3D Devices Passive Glasses

Passive Glasses – eg. ZScreen system

Advantages: refresh rate < active glasses cost per. user

no power supply no synchronization

Disadvantages: lower dynamic range

transmission may suffer ghosting image cross talk

Stereo & 3D Display Technologies3D Devices

Stereo & 3D Display Technologies3D Devices The Pulfrich Technique

Passive Glasses – neutral density filter

•German physicist Carl Pulfrich (1858-1927)•perception in the covered eye is delayed by optical filter•direct image and the delayed image will form a stereo pair

Disadvantages: requires constant motion illusion motion dependent does not replicate human stereo

Stereo & 3D Display Technologies3D Devices FAKESPACE Push Display

Fakespace Systems Inc.

M1 Desk

Fakespace PUSH

Fakespace Dstation

µPol Technology Parallax Barrier

Stereo & 3D Display Technologies3D Devices Time Parallel / glasses/no glasses

3.5 Time Parallel/ ~Large Format Displays

Stereo & 3D Display Technologies

Example of large Format Displays: IMAX Fakespace Systems Displays VisionDome

Large Format Displays

Why Large Format Displays?

To overcome the limited field of view and low resolution of HMDs.

Allowing the user to move in space (requires position tracking)

Experiencing highly immersive display environments

Moving towards the commercial side

Immersive Room

Source: http://www.fakespacesystems.com

IMAX Cinema; Source: http://www.imax.ac

How? Projection systems have been developed that use large projection surfaces to simulate immersion.

Stereo & 3D Display TechnologiesLarge Format Displays IMAX

Source: www.imax.ac

IMAX 3D Camera http://www.sciencemuseum.org.uk/imax/

IMAX

Create the illusion that you are really 'in the picture' and not just watching it

IMAX (Image MAXimum) Uses the standard filed-sequential polarized projection

mechanism to project stereo images onto a huge screen that encompasses the viewer's peripheral vision.

Users wear passive glasses. These glasses use matching polarization filters in front of the projector lenses and the eyes.

The viewing distances are large. In this viewing context, both

accommodation and binocular parallax are almost entirely lost.

Stereo & 3D Display TechnologiesLarge Format Displays Fakespace Systems Display

-- Cave™ is the Most Widely Installed Fully Immersive Visualization System in the World.

-- Concept behind the CAVE™ also known as walk-through/fly-through: A complex, 3D model of a building, structure, or other physical space through which you can move your viewpoint as if walking or flying through it. -- To produce a walk-through: create a scene for every possible point of view and field of view, then display the scene based on the participant's input.

-- Fakespace System is the major provider of Immersive Rooms (i.e. CAVE™)


CAVE: “CAVE Automatic Virtual Environment”• Typically shutter technology is used to present alternate left/right eye frames to the viewer, hence is immersed in a completely surrounding VE.•Single participant + Several people can be situated in the CAVE at the same time, though the display is completely correct for one participant• Could be Multi-participant! HOW?


These pictures are an artistic representation of the layout of the CAVE™, showing all the different components that make up the whole system.

The Display SystemProjectors Projection Wall (Ideally a CAVE™ is a room that has all six walls as projection screens, on which a virtual environment (VE) is projected)

Mirrors

Shutter Glasses (A participant wears lightweight stereo glasses with a head-

tracking device mounted)

Source: http://www.cave.rdg.ac.uk/

The Tracking SystemHead Tracking and Wand User can interact with the image/environment using various input devices.

How CAVE™ is constructed and How it works:

Possible drawbacks to CAVE™?


The FLEX™ is the world's first commercial re-configurable visualization solution for those whose viewing, collaboration, and presentation requirements cannot be met within the confines of a single visualization technology.

FLEX™ and reFLEX™

These new systems designed by Fakespace:

allow a for single-person configuring,

fully detached module capabilities!

-- Fact: The fact that VE sites represent both academic and commercial interests suggests that VR is extending beyond research labs and science fiction into the real world.


Stereo & 3D Display TechnologiesLarge Format Displays The VisionDome

The VisionDome delivers a full-color, raster based, interactive display, with 360 degree projection and a 180 degree field of view.

-- The tilted hemispherical screen is positioned so as to fill the field-of-view of the participants, creating a sense of immersion in the same way that large-screen cinemas draw the audience into the scene.

-- The dome itself allows freedom of head motion, so that the observer can change their direction of view, and yet still have their vision fully encompassed by the image.

Source: http://www.elumens.com

VisionDome is an immersive digital environment that, via proprietary projection and rendering technologies creates 3D display.

Stereo & 3D Display TechnologiesLarge Format Displays The VisionDome

Elumens offers a family of VisionDome models for audience sizes from 1 to 45 people.

VisionDome VS. IMAX!

In contrast with the large format, analogue film used for entertainment in domed cinemas (e.g. IMAX), the VisionDome is driven by digital media, either pre-recorded or generated in real-time from a computer or High Definition TV camera.

Source: http://www.elumens.com

•Designed to be deployed for 3D applications in which many people need to participate jointly. •Since there is only one projection source and nothing to wear, the VisionDome is the best solution for collaborative environments.

Stereo & 3D Display TechnologiesAutostereoscopic Displays

Forget the Funny Glasses

In the last 10 years, stereo displays that don’t requireglasses have emerged from the laboratories into the marketplace.

Autostereoscopic displays (ASDs) use several technologies to present different images to both of a viewer’s eyes.

No one technology has yet become dominant in the ASD marketplace.

Most common are systems based on flat panel displays (FPDs), which use either lenticular screens or parallax barriers to provide binocular disparity.

QinetiQ's groundbreaking 3D Autostereo technology allows multiple viewers to see geometrically accurate

and stable, 3D perspectives simultaneously.

Source: http://www.qinetiq.com

What Technology they use for ASDs:

The manufacturers attempt to use optical tricks to aim the waves of light emitted by the monitor directly at the viewers eyes. If the viewer's head is within a certain area in front of the screen, the so called stereo zone, the scene will appear to be in 3D.

http://www.qinetiq.com/

http://www.qinetiq.com/

Stereo & 3D Display TechnologiesAutostereoscopic Displays

Autostereoscopic Displays: No Viewing Devices

Required

I. Hardcopy (Such as: Free Viewing, Holographic Stereograms, Parallax Barriers, Lenticular Sheets) .

II. Alternating PairsIII. Moving Slit Parallax Barrier (A variation of the Parallax

Barriers)• The Sanyo Display

IV. The DTI SystemV. Seaphone DisplayVI. The Sanyo DisplayVII. The HinesLab Display

I, II and IV-VII are not covered

Stereo & 3D Display TechnologiesAutostereoscopic Displays The DTI System

Source: http://www.dti3d.com

The Dimension Technologies IncWith the DTI display, stereoscopic imaging is accomplished with a special illumination pattern and optics behind the LCD screen (figure 1) which make alternate columns of pixels visible to the left and right eyes (figure3) when you are sitting in front of the display (figure2), or in certain areas off to the side.

One can see 3D from any position where the left eye is in a left eye zone and the right eye is in right eye zone. Additionally, there is little effective vertical restriction.

Stereo & 3D Display TechnologiesAutostereoscopic Displays The Sanyo Display

Use LC technology

Head tracking System

Use two image splitter

No ghosting

The Sanyo Display

More information about different 3D displays at: http://www.stereo3d.com/displays.htm

Sanyo 3D Screen: 15 inch LCD monitor with non-glasses stereo 3D display. Uses

eye-tracking.

Stereo & 3D Display Technologies

Volumetric DisplaysAlso called Multiplanar 3D displays

>>>Several technologies of volumetric displays exist: Oscillating Plane Mirror Varifocal Mirror Rotating Mirror

Volumetric Displays

-- Volumetric display systems (VDSs) create an image with true depth, letting the eyes and brain work in a natural manner.

Crorepressor protein interacting with DNA

Actuality Systems Volumetric 3-D Display http://www.actuality-systems.com/

-- VDSs Normally depend on moving mirrors, rotating LEDs or other optical techniques to project or reflect light at points in space

Stereo & 3D Display TechnologiesVolumetric Displays

-- A stereo image hovering in free space, visible from any viewpoint. This is achieved by projecting the images onto a fast rotating surface.

-- Allows stereo vision, motion parallax, and proper accommodation.

-- Expensive!!

-- Since the display medium is transparent, it lacks the ability to produce occlusion. Therefore, this display system would not be ideal for video.

Actuality System

Stereo & 3D Display TechnologiesVolumetric Displays Oscillating Plane Mirror

No disconnection of accommodation

All depth cues would be consistent

According to the focal length of The mirror, dramatic improvement in view volume depth can be obtained.

Oscillating Plane Mirror

Stereo & 3D Display TechnologiesVolumetric Displays Varifocal Mirror

A commercial multiplanar

Use a flexible circular mirror anchored at the edges.

It is difficult to build a high quality varifocal optic that can be oscillated at high frequencies.

Varifocal Mirror

A varifocal mirror display.

Stereo & 3D Display TechnologiesVolumetric Displays Rotating Mirror

•ASD and VDS systems are intended to replace current 3D displays, all of which require the user to wear some sort of filtering system, such as eyeglasses.

Rotating Mirror

Use RGB lasers for point plotting and a double helix mirror rotating at 600 rpm as reflecting

device

Stereo & 3D Display TechnologiesVolumetric Displays New Technology

Stereo & 3D Display Technologies7. Retinal Scanning Technologies

Stereoscopic Displays and Virtual Reality Systems X, SPIE Vol. 5006


Accommodation vs. Vergence

seminar series: stereo systems: overview adapted from: “stereo & 3d display technologies”...

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