VIRTUAL REALITY VR INTRODUCTION AND BASIC APPLICATIONS Dr

VIRTUAL REALITY (VR) INTRODUCTION AND BASIC APPLICATIONS Dr. Naji Shukri Alzaza Assist. Prof. of Mobile technology Dean of Community Service and Continuing Education University of Palestine, Alzahra City, Gaza, Palestine najishukri@hotmail. com, www. najishukri. wordpress. com ﻣﻘﺪﻣﺔ ﻭﺗﻄﺒﻴﻘﺎﺕ : ﺍﻟﻮﺍﻗﻊ ﺍﻻﻓﺘﺮﺍﺿﻲ

4 VR OUTPUT DEVICES

Objectives 3 Students should be able to understand the: VR visual output display Desktop Display, Spatially Immersive Display (SID), Head Mounted Display (HMDs), Workbench and Wall VR auditory display Sonification of Interface, Sound Effects, Environmental Audio, Spatialized Audio, Speech Generation VR haptic display Tactile, Force, Motion Platform Dr. Naji Shukri Alzaza

VR Output Devices 4 In VR systems, one goal is to involve as many of the user’s senses. So displays have been searched for almost all of the senses (visual, auditory, haptic (touch), olfactory (smell) and vestibular (motion). Current research has ventured into gustatory (taste) display. This lecture will concentrate on the 3 most common types of displays: VISUAL, AUDITORY and HAPTIC. Dr. Naji Shukri Alzaza

VR Visual Output Display 5 Visual display is the indispensable piece of hardware in VR system. Often it reflects the type of VR system. There are 4 general categories of VR visual displays: Desktop Displays Spatially Immersive Displays (SID) Head Mounted Displays (HMDs) Workbenches and Walls Dr. Naji Shukri Alzaza

1. Desktop Displays 6 The most common VR visual displays – desktop monitor used for Desktop VR. Sometimes such displays are enhanced by using stereo graphics and stereo glasses to allow better depth perception. But for the most part, desktop displays are identical to the displays used by all computer users. Dr. Naji Shukri Alzaza

2. Spatially Immersive Displays 7 To achieve immersiveness a more complex visual display device is needed that allows the VE to appear to surround the user, or that fills the user’s Field of View (FOV) with the computer graphics. SID approach – to physically surround the user with the display. Example : CAVE – uses 4 -6 large projection screens in the shape of a cube into which the user can walk. Dr. Naji Shukri Alzaza

2. Spatially Immersive Displays 8 Stereo graphics are projected onto the screens, so that user sees nothing but the VE and their own body. The CAVE allow multiple viewers unlike some other VR technologies, but only one viewer has the correct perspective view. Dr. Naji Shukri Alzaza

2. Spatially Immersive Displays 9 Inside a CAVE System Dr. Naji Shukri Alzaza

2. Spatially Immersive Displays 10 Another type of SID – Dome / Hemispherical Display, uses only a single curve screen that wraps around the user to provide immersion. The Hemispherium is an example of this type of display. It uses a six meter dome mounted vertically. The user sits in front of the dome so that the display fills his entire field of view. SID often provide excellent sensations of presence and high resolution graphics but can be costly and are usually not fully immersive (except in the case of 6 sided CAVE. ) Dr. Naji Shukri Alzaza

2. Spatially Immersive Displays 11 User seated in the flight chair of the Hemispherium Dr. Naji Shukri Alzaza

3. Head Mounted Display 12 HMD was the earliest VR display and represents another method for achieving immersion. HMDs use 2 small LCD or CRT screens mounted inside a helmet worn on the head. § user’s The HMDs blocks out the user’s view of the physical world so that only the virtual world can be seen. When the HMD is combined with a head tracker, the user can view the VE Dr. Naji Shukri Alzaza in any direction simply by turning his head.

3. Head Mounted Display 13 HMD can be much less costly and more portable than SID and provide complete physical immersion. However they have a narrow field of view (3090 degrees horizontally), a low display resolution (typically 640 x 480 or 800 x 600) and can be heavy and cumbersome. Dr. Naji Shukri Alzaza

4. Workbench / Wall 14 Another approach to providing some level of immersion and wide field of view (FOV) is to use a single, flat, very large display surface. Typically this takes the form of a horizontal screen upon which the user looks down (workbench) or a vertical screen mounted in front of the user (wall). Most workbench/ wall displays user rearprojected stereo graphics and stereo glasses for the user. Head tracking is also common although not Dr. Naji Shukri Alzaza required.

4. Workbench / Wall 15 Some display such as Immersive Workbench allows the screen to be rotated to produce a workbench configuration, a wall configuration or anything between. Workbenches and walls provide only limited immersion, but they do allow multiple users to share the display and afford direct manipulation of the displayed data. Dr. Naji Shukri Alzaza

Auditory Display 16 Audio plays a significant role in VEs. User’s sense of presence may be increased considerably by the use of sounds during navigation and interaction. Naturalness of audio can be achieved by both the presented audio spectrum (the number of different kinds of sounds used) and the sound locations. Employing spatial sound allows the participant to become aware of the location and direction of sound. The audio signals continuously change to reflect the participant’s movements, creating a feeling of space. Dr. Naji Shukri Alzaza

Auditory Display 17 Many advanced VR systems use spatial audio, which presents auditory information that sounds as if its source is at a particular location in 3 D space. Audio sub-topics: 1. Sonification (Use of non-speech audio to convey information) 2. Sound Effects (Classic Multimedia, game tool) 3. Spatialized Audio (2 ears allow localization) 4. Environmental Audio (Air Absorbtion, Room acoustics) 5. Speech Generation (Prerecorded words, phonemes and diphones) Dr. Naji Shukri Alzaza

Auditory Display 18 Audio Display Devices – PC sound boards – External 3 D Processor – External synthesizer, mixer – Stereo Headset – Stereo speakers – Multiple Speakers – Bass Shaker Speaker – Amplifiers Dr. Naji Shukri Alzaza

Haptic Display 19 Terminologies Haptic - Relating to the sense of touch. Kinaesthetic - Meaning the feeling of motion. Relating to sensations originating in muscles, tendons and joints. Tactile - Pertaining to the cutaneous sense the sensation of pressure Force Feedback - Relating to the mechanical production of information sensed by the human kinesthetic system. Dr. Naji Shukri Alzaza

Haptic Display 20 Tactile information is produced by perturbing (disturbing) the skin • • Pins - either alone or in an array, as in devices for Braille display and typically used for fingertip stimulation. Air jets blow to produce a disturbance. Cushions of air can be inflated or deflated to vary pressure on skin. Electrical stimulation -low levels of current provide a localized tingling sensation. Typically used in gloves, or for larger body areas. Dr. Naji Shukri Alzaza

Haptic Display 21 VITAL (acronym for Vibro. TActi. Le) Cyber. Touch Dr. Naji Shukri Alzaza

Haptic Display 22 Kinesthetic haptic devices are available, either in laboratories or commercially, for a wide range of application areas including: Desktop Interfaces: Interfaces are developed for desktop application like Virtual Sculpture or Computer Aided Design. They are intended to be used with a workstation and act as a 6 DOF mouse with force feedback. General Haptic Interfaces / Hi-Fidelity Teleoperation: Interfaces are intended for general purpose haptics and teleoperation applications requiring high precision and sensitivity (like telesurgery). Dr. Naji Shukri Alzaza

Haptic Display 23 Scale One Interfaces / Remote Handling : These interfaces are used in workbenches or large scale environments to virtually simulate real manipulation as close as possible to scale one. Hand exoskeletons: They are intended to allow natural finger interaction. Ease of use and adaptability to general public is of particular importance. Arm exoskeletons: They are intended to allow natural hand interaction. They can also be used for rehabilitation purposes. Dr. Naji Shukri Alzaza

Haptic Display 24 Many types of haptic display in VE. The most common type is a mechanical linkage device that displays force to the user at a single point, such as the Phantom device. This device allows users to probe virtual objects with a fingertip or stylus in order to feel the surface. PHANTOM 1. 5 High Force / 6 DOF Dr. Naji Shukri Alzaza

Haptic Display Phantom 25 Dr. Naji Shukri Alzaza

Haptic Display 26 Exoskeleton allows users to grasp virtual objects and feel the force on all five fingers. These two types can be combined to allow both grasping and probing. Exoskeleton (left) and combination exoskeleton and mechanical linkage (right) haptic devices Dr. Naji Shukri Alzaza

Haptic Display 27 Dr. Naji Shukri Alzaza Exoskeleton

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