# Reality-Virtuality Technologies in the Field of Materials Science and Engineering
###### Abstract  
The increasing use of reality-virtuality technologies (RVTs, which encompass virtual, augmented, and mixed reality) in different fields over the last decade is a phenomenon for which materials science and engineering (MSE) is no exception. To obtain an overview of the implementation of RVTs in MSE, this team conducted a systematic search of the scientific literature published since 2010 addressing the use of RVTs in MSE. Forty-one relevant papers were selected and analyzed in depth to reach several conclusions, including: (i) most of the works (67.3%) are focused on the MSE area of materials structure, processing, and properties, which implies that there are great possibilities for research in other MSE areas; (ii) most of the works (86.8%) are aimed exclusively at education or research, which means that there are many fields outside of the university in which the use of RVT tools has not been developed and evaluated; (iii) the most used technology is virtual reality (85.1%), which means that there are many research possibilities focused on augmented and mixed reality. Researchers can find in the present work examples of the use of RVTs in MSE as well as other relevant information useful to open new lines of research and ideas that can contribute to their current and future work. materials science and engineering; virtuality continuum; virtual reality; augmented reality; mixed reality; education; engineering education; research; spatial visualization; history +
Footnote †: journal: Applied  
as the ears or hands [4]. Since then, the term VR has been used to define different systems and applications, both at the software and hardware level [6]. Within VR, it is common to differentiate non-immersive VR from immersive VR [6,7]. In the first case (non-immersive VR), the virtual environments are shown through a screen. Examples of non-immersive VR would be the virtual worlds such as Second Life [8] or most of the current 3D video games for video game consoles. In the second case (immersive VR), the aim is to create the sensory illusion of being completely present, immersed, in the virtual environment [9]. Examples of immersive VR would be the CAVE-type systems [6,10] or those in which head-mounted displays (HMDs) are used [6]. AR allows real-time visualization of the real physical world \"augmented\" thanks to the inclusion of information and virtual elements generated by the computer [11]. In this type of technology, real elements and virtual elements are combined [11]. The term AR was coined in 1992 by Boeing researchers [PERSON] and [PERSON] [12] when they described a system that allowed virtual information to be superimposed on a worker's field of vision to improve efficiency in the performance of manufacturing activities [13]. Currently, the use of AR technology is mainly linked to smartphones and tablets (as would be the case of the Pokemon Go game [14]), and to HMDs [7,15,16]. MR, as defined by [PERSON] and [PERSON] in 1994 [1], is conceptually close to AR, since both technologies combine real and virtual elements. However, MR implies not only the superimposition of virtual elements on a real environment as occurs with AR, but also these virtual elements must be indistinguishable from the physical world [17]. When using MR, virtual elements must be integrated into the physical world [16] and, therefore, visual coherence plays a decisive role in this type of technology [18]. MR allows users to interact in real-time with both real and virtual elements, with real elements being able to modify virtual elements [17]. As an example, if we imagine a virtual box under a table, a user using MR will not be able to see it until he/she crouches down and look under the table; on the contrary, a user using AR will always see the box superimposed on the table, without the need to bend down [17]. Nowadays, the main commercial system that allows MR to be implemented is Microsoft HoloLens [17,18].