Preface

Every time some new media appears, civilization accelerates in different directions. In the past, time seemed to move more slowly and was measured in weeks, days, hours, and minutes. Nowadays, it is measured in seconds, and surely there will come a time when it will be measured in milliseconds. We are currently living in the era of high-speed internet, laptops, smartphones, and watches, and we are rapidly approaching the moment when we will live in the time of a new medium, that of augmented and virtual reality.

Augmented Reality (AR) is a discipline that includes the interactive experience of a real-world environment, where real-world objects and elements are enhanced using computer perceptual information. AR adds elements of the virtual environment to the real world so that they look like part of it. This expands the user's view of the world with additional information that is directly embedded in the real world. In some applications it is not necessary to completely replace reality with a virtual world; sometimes it is only necessary to supplement or improve reality with some virtual parts.

AR can be defined as a system that incorporates three basic characteristics: a combination of the real and virtual world, real-time interaction, and precise verification and positioning of 3D virtual and real objects. AR changes the constant perception of the real-world environment, while virtual reality completely replaces it with a simulated one. AR is associated with two terms: Mixed Reality (MR) and Computer Mediated Reality (CMR).

AR is a relatively new area. Although the basic idea appeared in the beginning of the twentieth century, its rapid development didn't begin until the end of the same century; it has yet to achieve its full expansion. AR provides direct access to information and displays it in the user's field of vision, intertwining with the real world. This allows better, faster, and easier access to information. AR can be applied in medicine, manufacturing and maintenance, architecture, robotics, the military industry, and entertainment. When it comes to medical applications, AR can be used to overlay medical images with the patient, resulting in a kind of virtual X-ray that occurs in real-time. The result is that the doctor can see the patient's organs because the body is transparent. In production and maintenance, AR can be used to display visual instructions directly onto equipment/machinery, and thus the operator, instead of looking at the documentation, has all the necessary information at the right time in the right place. AR can be used in interior design to visualize structures or installations. For example, virtual furniture can be deployed in an actual room, thus one can get an impression of spatial relations and how the room will really look with the furniture. Military pilots can use AR to receive additional information and guidance as well as to see targets or guided missiles. In these cases, the AR display is built into the user's helmet or on the cabin.

AR is used to enhance the natural or real environment and offers perceptually enriched experiences. With the help of advanced AR technologies (computer vision, AR cameras in applications for smartphones and tablets, object recognition),

information about the real world of users in the environment becomes interactive and can be manipulated digitally. It should be noted that AR has a lot of potential in the collection and exchange of knowledge.

This book is divided into two parts: "Augmented Reality in Education and Medicine" and "Augmented Reality and Engineering."

The first section consists of five chapters. Although AR applications are used in many areas, the most important of these areas is education. AR technology allows the combination of real objects and virtual information to increase students' interaction with physical environments and facilitate their learning. The first chapter in this section discusses how AR technology enables students to learn complex topics in a fun and easy way through virtual reality devices. Students interact with objects in the virtual environment and can learn more about them. For example, by organizing digital tours of a museum or zoo in a completely different country, lessons can be taught in the company of a teacher as if they were there at that moment. The second chapter is dedicated to the experiences of lecturers who used VR resources at a university in South Africa. The third chapter discusses cytopathology using high-resolution digital holographic microscopy. The fourth chapter presents the latest advances in digital holography with one or more wavelengths as well as holographic microscopy. The fifth chapter reviews the available AR or extended AR for technical vocational education training and skill development and its relevance in increasing the impact of student learning in skill centers.

The second section contains six chapters. VR and AR provide researchers, government authorities, and rescue teams with tools for recreating emergencies entirely through computer-generated signals of sight, sound, and touch (in VR), and overlays of sensory signals for experiencing a rich juxtaposition of virtual and real worlds simultaneously (in AR). The gap between knowledge and action is filled with visual, aural, and kinesthetic immersive experiences that make it possible to attend to the population in danger in a deeply efficient way, never experimented before. The first chapter in this section is dedicated to this issue. The benefits of AR technologies have been well proven in collaborative industrial applications, for example, in remote maintenance and consultancy. Benefits may also be great in telepresence applications, where virtual and mixed reality (nowadays often referred to as extended reality or XR) technologies are used for sharing information or objects over a network. The second chapter is dedicated to the advances in spatially true 3D telepresence. The third chapter provides an overview of building data modeling and the current state of the art in the use of augmented reality in various user scenarios of building data modeling and explores various challenges that need to be addressed for the adoption of AR technology in architecture, engineering, and construction in general. Virtual tools with their pre-set operability limit the designer's ways of interaction with artefacts. The fourth chapter proposes a framework for designers to interact with non-design experts through enhanced communicative media. The design framework indicates steps of design thinking to develop the interface by understanding both the virtual artefacts' perceptual affordance to the users and the design task. The chapter discusses projects tested in three different scenarios: urban design, architecture, and product design. Inspired by ideas portrayed in science fiction, the authors seek to develop a set of AR fashions that showcase scenes from a science fiction novel recently published by the principal author. The development team included artists and designers, a programmer, and the writer. Significant technical challenges needed to be overcome for success, including fabric construction and manipulation, image enhancement,

robust image recognition and tracking capabilities, and management of lighting and suitable backgrounds. Viewing geometries were also a non-trivial problem. The final solution permitted acceptable but not perfect real-time tracking of the fashion models and the visualization of both static and dynamic 3D elements overlaid onto the physical garments. The fifth chapter is dedicated to this topic. AR is a technology that provides more interactive advertising, where you can manipulate and be part of it with greater clarity and empathy. In the digital era, companies in the retail sector face a new consumer profile that is more digital, more aware, and more informed. Therefore companies are in constant competition to impress their customers. The sixth chapter in this section describes the importance of AR in promoting products and services as an innovative alternative that captures attention and influences customer purchase decisions.

I would like to express my sincere gratitude to all the authors and co-authors for their contributions. TI would especially like to thank Publishing Process Manager Ms. Karmen Đaleta at IntechOpen for her support during the publishing process.

> **Dragan Cvetković** Singidunum University, Beograd, Serbia

Section 1
