VRMController: An input device for navigation activities in virtual reality environments Hai-Ning Liang*, Yuwei Shi, Feiyu Lu, Jizhou Yang, Konstantinos Papangelis Xi’an Jiaotong-Liverpool University, Suzhou, China (a) (b) (C) (d) (e) Figure 1. (a-d) Screenshots of the VRMController: (a) the main interface implemented on a mobile device; (b) moving the red dot allows going forward, backward, left and right; (c-d) turning the phone right/left to turn the viewport right/left as if the body of the person is turning; (e) the experimental virtual reality environment simulating a 3-floor shopping mall. Abstract Despite the rapid advancement of display capabilities of VR, in the form of wearable goggles like the Oculus for example, there CCS Concept: • Human-centered computing~Touch has been relatively limited progress in the development of input screens • Human-centered computing~Gestural input devices for this technology. In this paper, we describe an input controller that is aimed at supporting users’ navigation activities 1 Introduction in virtual reality environments. Navigation is common in VR environments. The traditional game controller for consoles is still Virtual reality (VR) is an emergent technology. Its visual quality a common choice but only now companies are just beginning to has advanced rapidly in recent years. There are now many types introduce new concepts (for example the HTC Vive Controller). of headsets with high resolution displays on the market. In In this research we explore the development of an alternative contrast, development of input devices to allow users to input controller to support users’ navigation activities. This manipulate VR content still lags behind. Navigation or moving process has led to the design and creation of VRMController, an around within a VR environment is one of most common input device based on a mobile phone designed specifically to activities users do. This can be typically seen in games that support single-hand interaction within VR environments. The simulate 3D environments. The default input device for VR design VRMController is based on the results of an initial study headsets is still based on controllers for game consoles. Figure 2 comparing three input devices: an Xbox game controller, the HTC (Bottom, Left) is an example of a commercial headset with a Vive controller, and a tablet device. Based on feedback from controller that is based on a game controller. Other commercial participants about the useful features of the three types of devices, products, such as the HTC Vive (Figure 2, Right) and Oculus we have distilled five design guidelines and used them to inform RIFT, have their own concept input device designed from ground- the development of VRMController. The results of a second study up aimed specifically at VR technologies. comparing our controller with an Xbox controller shows that with our controller participants are able to achieve better performance and find that it is easier to use and more usable. Keywords: input devices, virtual environment, navigation interaction, interface design, mobile device, usability study Figure 2. (LEFT) The PICO commercial VR headset with its *e-mail: [email protected] Permission to make digital or hard copies of all or part of this work for dedicated controller based on game consoles (see also personal or classroom use is granted without fee provided that copies are http://www.picovr.com/neo.html). (RIGHT) The HTC Vive with its not made or distributed for profit or commercial advantage and that copies specialized two handed controller and motion tracking sensors bear this notice and the full citation on the first page. Copyrights for (see also https://www.vive.com/us/product/). components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to The game controller has been adopted because there are not many post on servers or to redistribute to lists, requires prior specific permission alternatives. Also there is an assumption that interaction with and/or a fee. Request permissions from [email protected]. content in VR headsets is similar to interacting with content VRCAI '16, December 03-04, 2016, Zhuhai, China shown in conventional displays. The main aim of this research is © 2016 ACM. ISBN 978-1-4503-4692-4/16/12…$15.00 DOI: http://dx.doi.org/10.1145/3013971.3014005 to develop an input device to support users’ navigation activities within VR environments. The outcome of the process is VRMController (short for Virtual Reality Mobile Controller), a 455 mobile phone-based device that allows ambidextrous single hand al., 2006; Tan et al., 2006]. Besides these devices, mobile devices interaction. Figures 1a-d show the main interface of the controller have been touted as possible input controller for a variety of and how it can be used with one hand. We tested the controller interactive systems [Pering et al., 2005; Ballagas et al., 2006]. within a VR environment that simulates a shopping mall with Researchers have introduced a variety of implementations based three floors. The design of VRMController is based on a first on using touch-enable mobile devices as controllers (e.g., see study comparing a game controller, the Vive controller, and a [Boring et al., 2007; Dearman et al., 2009; Katzakis and Hori, tablet mobile device. Based on performance results and feedback 2009, 2010; Jeon et al., 2010; McCallum and Irani, 2009; Liang et from participants, we took the features of the three to design al., 2013]). These however are not conducted in the context of VRMController. We then did a second study comparing it with navigation activities but primarily as input devices for broad the traditional game controller. Results show that it has better time tasks, such as manipulating 3D objects (e.g., [Katzakis and Hori, performance than the game controller and that participants find it 2009, 2010]). often more usable. Du et al. [2011] have proposed the use of the tilt and touch The contributions of this paper include: (1) an examination of capabilities of a mobile to enable 3D interaction. Their research three types of input devices for navigation activities in VR indicates that by leveraging the capabilities of mobile devices, a environments; (2) a set of design criteria to aid designers; and (3) suitable controller to support navigation activities can be the introduction of an alternative input device to support these developed. They provide a scenario of using interface on a mobile activities. as a controller for flying around a 3D world. Their research, however, do not provide any usability analysis and comparative In the following sections, we described work related to this evaluation of their interface. Furthermore, their work has not been research. The next two sections will present the two experiments. based on VR systems. Finally, we present the conclusions at the end. Another advantage of an interface based on mobile devices is that 2 Related work it can easily be modified and adapted to meet the specific needs of users. For example, buttons can be positioned and their size In this section we will discuss two aspects related to this research. adjusted based on the size of users’ hands. The adaptability is not The first aspect is about prior research on navigation within VR possible in other physical devices such as game controllers or the environments. This is followed by a discussion about input Oculus Touch. devices for interacting with VR content. Finally, the research goal for this project is described in more detail. 2.3 Research goal Given the lack of research on the suitability of input devices for 2.1 Navigation in VR supporting navigation activities using VR headsets, this research is an attempt to fill this gap. To achieve this, we run an initial 3D Navigation has been studied in traditional TV/computer exploratory study of 3 types of input devices. The first type is displays and CAVE-type of 3D environments [Chen, 2004; Tan et what is normally chosen to use: A controller for game consoles al., 2006; Cliburn et al., 2007]. Research suggests that immersion such as the Xbox and PlayStation. The second type represents a is more conducive to enhanced experiences navigating 3D spaces new class of controllers such as the HTC Vive and Oculus Touch in 2D screens. For example, Tan et al. [15], from a series of (see Figure 2 above). These two devices rely on both hands studies involving users in navigating 3D spaces, reported several holding a device that is tracked by external sensors. At the time of advantages of using large displays as compared to smaller, this research, only the HTC Vive was available in the market so desktop size screens. Due to the bigger size of the displays, users we chose it to explore its suitability for navigation activities. The had a greater sense of immersion and that helped them develop third type is a virtual controller that is implemented on a mobile better cognitive maps of the virtual worlds, which subsequently device (in the first experiment a tablet) because we wanted to led users to perform better in their navigation tasks in 3D (also simulate the functions of the game controller to assess if people supported by [Bakdash et al., 2006]). VR headsets are intended to will find it possible to use. Although we had hypothesized that the provide an even higher level of immersion and as such are thought Vive and tablet will underperform the game controller, we wanted to be suitable means to support navigating 3D virtual spaces. to conduct the experiment in an exploratory manner in order to distill useful features of these three types of devices. This process 2.2 Input devices for VR interaction led to development of five design guidelines which were then used to guide the development of VRMController.