**4.6.1 General characteristics of the cave**

The CAVE is a large theatre that sits in a larger room measured of a varied size. The walls of the CAVE are made up of rear-projection screens, and the floor is made of a downprojection screen. High-resolution projectors display images on each of the screens by projecting the images onto mirrors which reflect the images onto the projection screens. The user will go inside of the CAVE wearing special glasses to allow for the 3D graphics that are generated by the CAVE to be seen. With these glasses, people using the CAVE can actually see objects floating in the air, and can walk around them, getting a proper view of what the object would look like when they walk around it. This is made possible with electromagnetic sensors. The frame of the CAVE is made out of non-magnetic stainless steel in order to interfere as little as possible with the electromagnetic sensors. When a person walks around in the CAVE, the person's movements are tracked with these sensors and the video adjusts accordingly. Computers control this aspect of the CAVE as well as the audio aspects. There are multiple speakers placed from multiple angles in the CAVE that give the user 3D audio (http://en.wikipedia.org/wiki/Cave\_Automatic\_Virtual\_Environment).

#### **4.6.2 The first CAVE**

The first CAVE was developed in the Electronic Visualization Laboratory at the University of Illinois at Chicago. This was announced and demonstrated at the 1992 SIGGRAPH (Fisher, 2003). The CAVE was developed in response to a challenge from the SIGGRAPH 92 Showcase effort for scientists to create and show off a one-to-many visualization tool that utilized large projection screens. The CAVE answered that challenge, and became the third major physical form of immersive VR (after goggles 'n' gloves and vehicle simulators). Carolina Cruz-Neira, Thomas A. DeFanti and Daniel J. Sandin are credited with its invention. It has been used and developed in cooperation with the National Centre for Supercomputing Applications (NCSA), to conduct research in various virtual reality and scientific visualization fields. CAVE is a registered trademark of the University of Illinois Board of Regents (http://en.wikipedia.org/wiki/Cave\_Automatic\_Virtual\_Environment).

#### **4.6.3 How the CAVE works**

A lifelike visual display is created by projectors positioned outside the CAVE and controlled by physical movements from a user inside the CAVE. Stereoscopic LCD shutter glasses convey a 3D image. The computers rapidly generate a pair of images, one for each of the

The final category of interaction device is the wand or floating joystick. Basically, this device works exactly the same as a conventional joystick, but it is not attached to a base that sits on a tabletop. Instead, the joystick is equipped with an orientation tracker so the user simply holds it in their hand and tilts it. Most flying joysticks also have some buttons on the stick

Cave Automatic Virtual Environment (CAVE) is an immersive virtual reality environment where projectors are directed to three, four, five or six of the walls of a room-sized cube (Fisher, 2003; http://en.wikipedia.org/wiki/Cave\_Automatic\_Virtual\_Environment).

The CAVE is a large theatre that sits in a larger room measured of a varied size. The walls of the CAVE are made up of rear-projection screens, and the floor is made of a downprojection screen. High-resolution projectors display images on each of the screens by projecting the images onto mirrors which reflect the images onto the projection screens. The user will go inside of the CAVE wearing special glasses to allow for the 3D graphics that are generated by the CAVE to be seen. With these glasses, people using the CAVE can actually see objects floating in the air, and can walk around them, getting a proper view of what the object would look like when they walk around it. This is made possible with electromagnetic sensors. The frame of the CAVE is made out of non-magnetic stainless steel in order to interfere as little as possible with the electromagnetic sensors. When a person walks around in the CAVE, the person's movements are tracked with these sensors and the video adjusts accordingly. Computers control this aspect of the CAVE as well as the audio aspects. There are multiple speakers placed from multiple angles in the CAVE that give the user 3D audio (http://en.wikipedia.org/wiki/Cave\_Automatic\_Virtual\_Environment).

The first CAVE was developed in the Electronic Visualization Laboratory at the University of Illinois at Chicago. This was announced and demonstrated at the 1992 SIGGRAPH (Fisher, 2003). The CAVE was developed in response to a challenge from the SIGGRAPH 92 Showcase effort for scientists to create and show off a one-to-many visualization tool that utilized large projection screens. The CAVE answered that challenge, and became the third major physical form of immersive VR (after goggles 'n' gloves and vehicle simulators). Carolina Cruz-Neira, Thomas A. DeFanti and Daniel J. Sandin are credited with its invention. It has been used and developed in cooperation with the National Centre for Supercomputing Applications (NCSA), to conduct research in various virtual reality and scientific visualization fields. CAVE is a registered trademark of the University of Illinois Board of Regents (http://en.wikipedia.org/wiki/Cave\_Automatic\_Virtual\_Environment).

A lifelike visual display is created by projectors positioned outside the CAVE and controlled by physical movements from a user inside the CAVE. Stereoscopic LCD shutter glasses convey a 3D image. The computers rapidly generate a pair of images, one for each of the

for "clicking" or selecting, similar to a mouse (Hsu, 1993).

**4.6 Cave Automatic Virtual Environment** 

**4.6.1 General characteristics of the cave** 

**4.6.2 The first CAVE** 

**4.6.3 How the CAVE works** 

user's eyes. The glasses are synchronized with the projectors so that each eye only sees the correct image. Since the projectors are positioned outside of the cube, mirrors often reduce the distance required from the projectors to the screens. One or more computers, often SGI workstations, drive the projectors. Clusters of desktop PCs are popular to run CAVEs, because they cost less and run faster (http://en.wikipedia.org/wiki/ Cave\_Automatic\_Virtual\_Environment).

#### **4.6.4 Developments in CAVE research**

The biggest issue that researchers are faced with when it comes to the CAVE is size and cost. Researchers have realized this and have come up with a derivative of the CAVE system, called ImmersaDesk. With the ImmersaDesk, the user looks at one projection screen instead of being completely blocked out from the outside world, as is the case with the original CAVE. The idea behind the ImmersaDesk is that it is a single screen placed on a 45-degree angle so that the person using the machine has the opportunity to look forward and downward. The screen is 4' X 5', so it is wide enough to give the user the width that they need to obtain the proper 3D experience. The 3D images come out by using the same glasses as were used in the CAVE. This system uses sonic hand tracking and head tracking, so the system still uses a computer to process the users' movements (http://en.wikipedia.org/ wiki/Cave\_Automatic\_Virtual\_Environment).

This system is much more affordable and practical than the original CAVE system for some obvious reasons. First, one does not need to create a "room inside of a room". That is to say that one does not need to place the ImmersaDesk inside of a pitch-black room that is large enough to accommodate it. One projector is needed instead of four and only one projection screen. One does not need a computer as expensive or with the same capabilities that are necessary with the original CAVE. Another thing that makes the ImmersaDesk attractive is the fact that since it was derived from the original CAVE, it is compatible with all of the CAVE's software packages and also with all of the CAVE's libraries and interfaces (http://en.wikipedia.org/wiki/Cave\_Automatic\_Virtual\_Environment).

#### **4.6.5 Applications of CAVE**

The concept of the original CAVE has been reapplied and is currently being used in a variety of fields. Many universities own CAVE systems. CAVEs are used for many things. Many engineering companies use CAVEs to enhance product development. Prototypes of parts can be created and tested, interfaces can be developed, and factory layouts can be simulated, all before spending any money on physical parts. This gives engineers a better idea of how a part will behave in the entire product (http://en.wikipedia.org/wiki/ Cave\_Automatic\_Virtual\_Environment).

#### **5. Software tools for VR application development**

As interest in Virtual Reality technology has increased, so has the number of tools available to the developers of virtual worlds. Some of these are libraries and toolkits, while others are application frameworks, and still others are full development environments, integrating every aspect of the creation of a VR application – modeling, coding, and execution – into a single package (Bierbaum & Just, 1998). The software

A Survey of Some Virtual Reality Tools and Resources 35

This is a light (Prime) to full featured (Studio) 3D package by MAXON Computer GmbH. Cinema 4D is used for creating advanced 3D graphics quickly and easily. Although used in film usually for 2.5D work, Cinema's largest user base is in the television motion graphics and design/visualisation arenas. Originally developed for the Amiga, it is also available for Mac OS X and Windows (http://www.maxon.net/products/cinema-4d-studio/who-

GL Studio creates interactive 3D graphics, instrumentation and user interfaces for training, simulation, and virtual prototyping. It generates portable C++ and OpenGL source code that can run standalone or be easily integrated into existing programs

Cobalt is a parametric-based computer-aided design (CAD) and 3D modeling software for both the Macintosh and Microsoft Windows. It integrates wireframe, freeform surfacing, feature-based solid modeling, photo-realistic rendering, and animation

EIAS is an eminent 3D animation and rendering package available on both Mac OS X and Windows. Mostly known for its rendering quality and rendering speed it does not include a built-in modeler. EIAS is extensively used in Hollywood, and by professional studios all over the globe to create world-class animations. The popular film *Pirates of the Caribbean* and the television series *Lost* used the software (http://www.eias3d.com/products/eias-

This is used for visual effects and character animation. It was used in Disney's feature film *The Wild*. Houdini uses a non-standard interface that it refers to as a "NODE system". It has a hybrid micropolygon-raytracer renderer, Mantra, but it also has built-in support for commercial renderers like Pixar's Renderman and mental ray (http://www.sidefx.com).

This software was first developed for the Amiga. It was originally bundled as part of the Video Toaster package and entered the market as a low cost way for TV production companies to create quality CGI for their programming. It first gained public attention with its use in the TV series *Babylon 5* and it is used in several contemporary TV series. Lightwave is also used in a variety of modern film productions. It is available for both Windows and Mac OS X. LightWave's tools are designed for fast productivity and easy, intuitive use

(http://www.simulation.com/products/glstudio/glstudio.html).

(http://www.ashlar.com/3d-modeling/3d-modeling-cobalt.html).

**5.1.8 Electric Image Animation System (EIAS)** 

(http://www.newtek.com/lightwave.html).

**5.1.5 Cinema 4D** 

should-use-it.html).

**5.1.6 GL Studio** 

**5.1.7 Cobalt** 

overview).

**5.1.9 Houdini** 

**5.1.10 LightWave 3D** 

components are divided into 3D modeling software, 2D graphics software, digital sound editing software and VR simulation software.
