Handheld mobile devices referring to mobile phones and tablets become the major output medium for augmented reality (AR), which have seen significant growth in popularity and usage among the public due to the growing release of consumer-oriented communication products nowadays, especially touchscreen smartphones. Unlike traditional desktop or tabletop AR (large display-based) and head-mounted display-based AR systems, small display-based AR (handheld mobile display) requires different interaction techniques that mostly utilize single-hand interaction as well as the limitation of small screen display and limited activity time due to the battery operation hour of handheld mobile devices. However, in handheld mobile AR, research is still lacking, especially research that focuses on 3D interaction in handheld mobile AR for virtual object manipulation. Thus, this paper provides an overview of 3D interaction techniques in handheld mobile AR with critical analysis. First, we describe three main interaction technique categories that applicable in handheld mobile AR, which is touch-based interaction, mid-air gestures-based interaction, and device-based interaction techniques, of their basic concepts on 3D object manipulation. Then, we classify and systematize the highlighted techniques and discuss the advantages and drawbacks of each. Previous studies for widely used techniques have been studied comprehensively. We then draw up a comparison among the different techniques based on the important elements considered in handheld mobile AR. The aim of this paper is to provide researchers with background information on AR and those who are interested in the field of 3D interaction, realizing each technique category.
INDEX TERMS 3D object manipulation, device-based interaction technique, mid-air gestures-based interaction technique, handheld mobile AR, touch-based interaction technique.
I. INTRODUCTIONAccording to Milgram and Kishino [1], augmented reality (AR) refers to all cases in which the display of an otherwise real environment is augmented by means of virtual (computer graphic) objects. Extended from this definition, Azuma [2] defined that AR is the variation of virtual environments or virtual reality; however, unlike virtual reality that immerses a user inside a synthetic environment and the user cannot see the real world around him/her, AR allows the user to see the real world, with virtual objects composited with the real world. Beyond that, some researchers have doneThe associate editor coordinating the review of this manuscript and approving it for publication was Waleed Alsabhan. a number of surveys or reviews about AR. For example, Krevelen and Poelman [3], drawing up conclusions from several previous works, defined the AR system as: 1) combining real and virtual objects in a real environment; 2) registering real and virtual objects with each other and 3) running interactively, in 3D and in real-time. From another point of view, Mekni and Lemieux [4] proposed to define AR as systems that have the following charact...