Basic Concept Involved In Augmented Reality:
Augmented Reality is a paradigm where virtual elements are added to a physical environment in real time. This helps in obtaining an increased or enriched scene. The resulting scene can be achieved by using various devices interacting with the added virtual information, either by modifying their state of position, rotation, or other deformation.
Augmented Reality is a variation of virtual environments, or Virtual Reality as it is more commonly known. Virtual Reality immerses the user in a synthetic environment generated by the computer. While immersed in it, the user can not see the real world around him. In contrast, augmented reality allows the user to view the real world with virtual objects superimposed on the real world, or compounds with it. Hence Augmented Reality acts as a complement to reality, much better than the Virtual Reality that completely replaces reality.
There are different applications development libraries of Augmented Reality. Among them, the main ones are:
The three libraries have common features where the use of paper marks (markers) are found in a physical scene where virtual elements are inserted and it leads to a physical scene enriched in virtual information. The markers are recognized by computer vision algorithms present in these libraries by using video capturing devices.
ARToolKit constitutes a set of libraries of C/C++ language. It is a development library originally designed by Hirokazu Kato and Billinghurst Marcos. It provides a number of functions for video capture and tracking patterns using computer vision techniques. It consists of various examples and utilities that greatly help the programmer to perform applications requiring Augmented Reality.
OSGART is a C++ cross-platform development library that simplifies the development of Augmented Reality or Mixed Reality applications. It is a powerful library for rendering, interaction and development of Augmented Reality applications.
FLARToolKit is a library of Actionscript, Flash (v3) version of ARToolKit that can be used to develop Augmented Reality on the web. FLARToolKit recognizes a visual mark of an input image, then calculates the camera orientation and position in the 3D world and layers of the virtual graphics on the video image. FLARToolKit supports all of the major flash 3D graphics engines Alternativa3D, Away3D, Away3D Lite, Papervision3D, Sandy3D. It is most often used in Augmented Reality web library based on Flash, with the support of a large community of developers.
Authoring tools (also known as author environments or visual languages) are applications that allow developing AR systems.They offer a work environment that enables icon-based programming, objects and menus with options enabling the user to create an augmented scene without writing a single line of code in any programming language.
Some of the Authoring Tools:
- DART (Designer’s Augmented Reality Toolkit)
DART is designed to support rapid prototyping of Augmented Reality applications. It consists of a set of extensions to the Macromedia Director multimedia-programming environment. Tracking markers on the video in real time is done through the ARToolkit Library.
ComposAR is intended for users with little or no programming knowledge. It can be used on different operating systems and provides a basis for Augmented Reality applications in education, design and research oriented activities.
ATOMIC is a tool that allows non-programmers to create Augmented Reality applications. It was created as a front to use the ARToolkit library without having to know programming.
The Hardware Setup:
The modern AR systems use one or more of these technologies: digital cameras, optical sensors, accelerometers, GPS, gyroscopes, solid state compasses, RFID, wireless sensors etc. The sound processing hardware could be included in AR systems. The cameras based on Augmented Reality systems require a powerful unit CPU and plenty of RAM to process images of these cameras. The combination of all these elements is often found in modern smartphones, which make them a possible Augmented Reality platform.
The Video Capturing Devices:
The devices used to capture the video in Augmented Reality applications are the webcams and Head Mounted Display (HMD). Web cameras provide the real-time video of Augmented Reality in which virtual information and the resulting scene is displayed on the computer monitor where the system is operating. The HMD is a device that acquires stereoscopic view of the video and displays the scene to the users. The use of this device has been tapped in creating games with Augmented Reality systems where users are completely immersed in a rich scene and become physical players in the game.
The Interaction devices:
Among the objectives of Augmented Reality systems it seeks to achieve interaction with upgraded scenes. Application developers use different physical devices to achieve interaction by users with virtual scene information.
Devices like markers can be used to select, place and modify enriched virtual scene elements. They can also be used to create the effect of magic lenses on these elements allowing users to access different levels of these geometries. Based on the principle of occlusion, anyone can create a real-time augmented scene and interact with it at the same time.
Just like markers, the device Wiimote can be used for handling as well as stretching, pulling and pushing the virtual information. Simulating a sharp object with the Wiimote, different cuts to the geometry of the virtual elements can be made.
It will be interesting to see if the Augmented Reality amalgamated with the Human Sensory would replace the current Computer Systems and Digital Devices in the near future.