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A Literature Review on Collaboration in Mixed Reality: Proceedings of the 15th International Conference on Remote Engineering and Virtual Instrumentation

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Mixed Reality is defined as a combination of Reality, Augmented Reality, Augmented Virtuality and Virtual Reality. This innovative technology can aid with the transition between these stages. The enhancement of reality with synthetic images allows us to perform tasks more easily, such as the collaboration between people who are at different locations. Collaborative manufacturing, assembly tasks or education can be conducted remotely, even if the collaborators do not physically meet. This paper reviews both past and recent research, identifies benefits and limitations, and extracts design guidelines for the creation of collaborative Mixed Reality applications in technical settings.
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A Literature Review on Collaboration in Mixed
Reality
Philipp Ladwig and Christian Geiger
University of Applied Sciences, 40476 D¨usseldorf, Germany,
{philipp.ladwig}{geiger}@hs-duesseldorf.de
Abstract. Mixed Reality is defined as a combination of Reality, Aug-
mented Reality, Augmented Virtuality and Virtual Reality. This inno-
vative technology can aid with the transition between these stages. The
enhancement of reality with synthetic images allows us to perform tasks
more easily, such as the collaboration between people who are at differ-
ent locations. Collaborative manufacturing, assembly tasks or education
can be conducted remotely, even if the collaborators do not physically
meet. This paper reviews both past and recent research, identifies ben-
efits and limitations, and extracts design guidelines for the creation of
collaborative Mixed Reality applications in technical settings.
1 Introduction
With the advent of affordable tracking and display technologies, Mixed Reality
(MR) has recently gained increased media attention and has ignited the imag-
inations of many prospective users. Considering the progress of research and
enhancement of electronics over recent years, we inevitably will move closer to
the ultimate device which will make it difficult to distinguish between the virtual
world and reality. Star Trek’s Holodeck can be considered as an ultimate display
in which even death can take place. Such a system would provide realistic and
complete embodied experiences incorporating human senses including haptic,
sound or even smell and taste. If it were possible to send this information over
a network and recreate it at another place, this would allow for collaboration as
if the other person were physically at the place where the help is needed.
As of today, technology has not yet been developed to the level of Star Trek’s
Holodeck. Olson and Olson [24, 25] summarized that our technology is not yet
mature enough, and that ”distance matters” for remote collaboration. But many
institutes and companies have branches at different locations which implies that
experts of different technical fields are often distributed around a country or
even around the world. But the foundation of a company lies in the expertise
of their employees and in order to be successful, it is critical that the company
or institute shares and exchanges knowledge among colleagues and costumers.
Remote collaboration is possible via tools such as Skype, DropBox or Evernote,
but these forms of remote collaboration usually consists of ”downgraded packets
of communication” such as text, images or video. However, machines, assembly
Fig. 1. Reality - Virtuality Continuum by Milgram and Kishino. [19]
tasks and 3D CAD data are increasingly getting more complex. Exchanging 3D
data is possible, but interacting remotely in real time on real or virtual spatial
data is still difficult [24, 25]. At this point MR comes into play, which have the
potential to ease many of the problems of todays remote collaboration.
Milgram and Kishinio [19] defined the Reality-Virtuality Continuum, as de-
picted in Fig. 1, which distinguish between four different stages: Reality is the
perception of the real environment without any technology. Augmented Reality
(AR) overlays virtual objects and supplemental information into the real world.
An example of an AR device is Microsoft HoloLens.Augmented Virtuality (AV)
captures real objects and superimposes them into a virtual scene. A video of a
real person, showed in a virtual environment, is an example for AV. Virtual Re-
ality (VR) entirely eliminates the real world and shows only computer generated
graphics. Head Mounted Displays (HMD) such as the HTC Vive or Oculus Rift
are current examples of VR devices. This paper focuses on Mixed Reality which
is defined by Milgram and Kishinio as a blend between AR and AV technology.
In the last three decades, research has shown a large amount of use cases for
collaboration in MR: Supporting assembly tasks over the Internet [2,3, 7, 23,34],
conducting design reviews of a car by experts who are distributed geographically
[12, 22] and the remote investigation of a crime scene [5, 30] are only a few
examples of collaborative applications in MR. Especially the domain of Remote
Engineering and Virtual Instrumentation can benefit from remote guidance in
MR. For example, many specialized, expensive and recent equipment or machines
can only be maintained by highly qualified staff and are not often available
at the location upon request if the machine happens to become inoperative.
Furthermore, remote education could assist in the prevention of such emergency
cases and help to spread specialized knowledge more easily.
The following sections chronologically describe the progress of research over
recent decades. A predominant scenario can be observed in user studies: A re-
mote user helps a local user to complete a task. Although, different authors use
different terms for the participants of a remote session, we will use the abbrevi-
ations RU for remote user and LU for local user.
2 Research until the year 2012
A basis function of collaboration in every study examined in this paper is bi-
directional transmission of speech. Every application uses speech as a foundation
for communication. However, language can be ambiguous or vague if it describes
spatial locations and actions in space. Collaborative task performance increases
significantly when speech is combined with physically pointing as Heiser et al.
[8] state. Some of the first collaborative systems, which uses MR, were video-
mediated applications as presented by Ishii et al. [9,10]. A video camera, which
was mounted above the participant’s workplace, captured the work on the table
and transmitted it to other meeting participants on a monitor. A similar system
was developed by Kirk and Fraser [11]. They conducted a user study in which
the participants had to perform a Lego assembly task. They found, that AR not
only speeds up the collaboration task but it was also easier for the participants
(in regards to time and errors) to recall the construction steps in a self-assembly
task 24 hours later when they were supported by MR technology instead of only
listening to voice commands.
Baird and Barfield [2] and Tang et al. [34] prove that AR reduces the men-
tal workload for assembly tasks. Billinghurst and Kato [4] reviewed the state
of research on collaborative MR of the late 90’s and concluded that there are
promising applications and ideas, but that they scratch just only the surface
of possibilities. It must be further determined, in which areas MR can be ef-
fectively used. Furthermore, Billinghurst and Kato mention that the traditional
WIMP-interface (Windows-Icons-Menus-Pointer) is not appropriate for such a
platform and must be reinvented for MR.
Klinker et al. [12] created the system Fata Morgana which allows for col-
laborative design reviews on cars and is capable to focus on details as well as
compare different designs.
Monahan, McArdle and Bertolotto [20] emphasize the potential of Gamifica-
tion for educational purposes: ”Computer games have always been successful at
capturing peoples imagination, the most popular of which utilize an immersive
3D environment where gamers take on the role of a character.” [20] Li, Yue and
Jauregui [14] developed a VR e-Learning system and summarize that virtual ”e-
Learning environments can maintain students interest and keep them engaged
and motivated in their learning.” [14]
Gurevich, Lanir and Cohen [7] developed a remote-controlled robot with
wheels, named TeleAdvisor, which carries a camera and projector on a movable
arm. The RU sees the camera image, can remotely adjust the position of the
robot and his arm with aid of a desktop PC and is able to project drawings and
visual cues onto a surface by the projector. A robot, which carries a camera,
has the advantage of delivering a steady image to the RU while a head-worn
camera by the LU lead to jittery recordings, which can cause discomfort for the
RU. Furthermore, a system controlled by the RU allows mobility, flexibility and
eases the cognitive overhead for the LU, since the LU does not need to maintain
the Point-of-View (PoV) for the RU.
To summarize this section, the transmission of information were often re-
stricted until the year 2012 due to limited sensors, displays, network bandwidth
and processing power. Many system rely on video transfer and were not capable
of transmitting the sense of ”being there” which restricts the mutual under-
standing of the problem and the awareness of spatial information.
3 New Technology introduces a sustainable change
After the year 2012, more data became available for MR collaboration due to
new technology. The acquisition and triangulation of 3D point clouds of the
environment became affordable and feasible in real time. Better understanding
of the environment results in more robust tracking of MR devices. Furthermore,
display technology was enhanced and enabled the development of inexpensive
HMDs. Tecchia, Alem and Huang [35] created one of the first systems which is
able to record the workplace as well as arms and hands of the RU and LU with
a 3D camera and allows the entrance of the triangulated and textured virtual
scene by an HMD with head tracking. The system revealed improvements in
performance over a 2D-based gesture system. Sodhi et al. [31] combines the
Mircosoft Kinect and a short range depth sensor and achieved 3D reconstruction
of a desktop-sized workplace and implemented a transmission of a hand avatar to
the remote participant. Instead of a simple pointing ray, a hand avatar allows for
the execution of more complex gestures, therefore delivering more information
among the participants for creating a better mutual understanding.
Moreover, the system by Sodhi et al. [31] is capable of recognizing real sur-
faces. Understanding surfaces of the real environment allows for realistic physical
interactions such as collision of the hand avatar with real objects such as a table.
If the position of real surfaces are available within the virtual world, snapping
of virtual objects to real surfaces is possible as well. This allows for decreased
time in placing virtual object in the scene such as a furniture or assembly parts.
If the environment is available as a textured 3D geometry, it can be freely
explored by the RU. Tait and Billinghurst [33] created a system which incorpo-
rates a textured 3D scan of a workplace. It allows the RU to explore the scene
with keyboard and mouse on a monoscoping monitor and allows the selection
of spatial annotations. It was found that increasing view independence (fully
independent view vs. fixed or freeze views of the scene) leads to a faster com-
pletion of collaborative tasks and a decrease in time spent on communication
during the task. Similar results are found by Lanir et al. [1] and explain: ”A
remote assistance task is not symmetrical. The helper (RU) usually has most
of the knowledge on how to complete the task, while the worker (LU) has the
physical hands and tools as well as a better overall view of the environment.
Ownership of the PoV (Point-of-View), therefore, does not need to be symmet-
rical either. It seems that for helper-driven (RU-driven) construction tasks there
is more benefit in providing control (of the PoV) to the helper (the RU)” [1].
Oda et al. [23] uses Virtual Replicas for assembly tasks. A Virtual Replica is a
virtual copy of a real-existing, tracked assembly part. It exists in real life for the
LU and it is rendered as a 3D model in VR for the RU. The position of the virtual
model is constantly synchronized with the real environment. Many assembly
parts of machines have complex forms and in some cases it is difficult for the LU
to follow the instructions of the RU in order to achieve the correct rotation and
placement of such complex objects. Therefore, virtual replicas, controlled by the
RU, can be superimposed in AR for the LU which eases the mental workload for
the task. Oda et al. found that the simple demonstration of how to physically
align the virtual replica on another machine part is faster compared to making
spatial annotations onto the Virtual Replicas as visual guidance for the LU which
allows for an easier placement. Oda et al. employs physical constraints such as
snapping of objects to speed up the task similar to Sodhi et al.
Poelman et al. [30] developed a system which is also capable of building a 3D
map of the environment in real-time and was developed with the focus to tackle
issues in remote-collaborative crime scene investigation. Datcu et al. [5] uses the
system of Poelman et al. and proves that MR supports Situational Awareness of
the RU. Situational Awareness is defined as the perception of a given situation,
its comprehension and the prediction of its future state as Endsley descriped [6].
Pejsa et al. [26] created a life-size, AR-based, tele-presence projection system
which employs the Microsoft Kinect 2 for capturing the remote scene and recreate
it with the aid of a projector from the other participant’s side. A benefit of such
a system is that nonverbal communication cues, such as facial expressions, can
be better perceived compared to systems where the participants wear HMDs
which covers parts of the face.
Mueller et al. [21] state that the completion time of remote collaborative
tasks, such as finding certain virtual objects in a virtual room, benefits by pro-
viding simple Shared Virtual Landmarks. Shared Virtual Landmarks are objects,
such as virtual furniture, which helps to understand deictic expressions such as
”under the ceiling lamp” or ”behind the floating cube”.
Piumsomboon et al. [28,29] developed a system which combines AR and VR.
The system scans and textures a real room with a Microsoft HoloLens and shares
the copy of the real environment to a remote user who can enter this copy by
a HTC Vive. The hands, fingers, head gaze, eye gaze and Field-of-View (FoV)
were tracked and visualized among both users. Piumsomboon et al. reveal that
rendering the eye gaze and FoV as additional awareness cues in collaborative
tasks can decrease the physical load (as distance traveled by users) and make
the task (subjectively rated by the users) easier. Furthermore, Piumsomboon et
al. offers different scalings of the virtual environment. Shrinking the virtual copy
of the real environment allows for a better orientation and path planning with
help of a miniature model in the users hand similar as Stoakley, Conway and
Pausch [32] show.
In summary, since technology has become advanced enough to scan and un-
derstand the surface of the environment in real time, important enhancements for
collaboration tasks were achieved and attested as important for efficient remote
work. 3D reconstruction of the participants’ body parts and the environment
allows for 1.) better spatial understanding of the remote location (free PoV) 2.)
as well as better communication because of transmission of nonverbal cues (gaze,
gestures) and 3.) allows for incorporating the real surfaces with virtual objects
(virtual collision, snapping). Furthermore, the 3D reconstruction of the environ-
ment implies better understanding of the environment which, in turn, leads to
4.) more robust tracking of devices (phones, tablets, HMDs, Virtual Replicas)
and 5.) new display technologies enables more immersive experiences which lead
to better spatial understanding and problem awareness for both users.
Fig. 2. a) View of a third collaborator through his HoloLens: Users design a sail ship
in a local collaboration scenario. One user is immersed by an VR HMD (HTC Vive)
while his collaborators uses an AR device (HoloLens). b) VR view of the Vive user:
The sail ship in the middle and the Vive controller at the bottom can be seen.
4 Insights from a Development of a Collaborative Mixed
Reality Application
We have developed an application in order to apply recent research outcomes
and we want to share our lessons learned of combining two tracking systems. Our
application is an immersive 3D mesh modeling tool which we have developed and
evaluated previously [13]. Our tool allows creating 3D meshes with the aid of
an HMD and two 6Degree-of-Freedom controllers and is inspired by common
desktop modeling applications such as Blender and Autodesk Maya. We have
extended our system with a server-client communication which enables users
with different MR devices to join a modeling session. Our tool can simulate how
colleagues can collaboratively develop, review and discuss ideas, machine parts
or designs.
It is created with the intent to be as flexible as possible. This includes: First,
the users are free to choose an AR or VR device such as HTC Vive or Microsoft
HoloLens. Second, the user can work with real objects, virtual replicas or entirely
virtual items. Third, the system is capable to work locally in the same room,
depicted in Figure 2a, or remotely at different places.
A use case demonstrates how our system works and give insights of connecting
and merging two different MR systems: A LU, using a HTC Vive, starts the
modeling application and hosts a session. A RU scans a fiducial marker with his
HoloLens in order to join the session. The marker has two purposes. First, it
contains a QR code with connection details such as an IP address to the server.
Second, it represents the origin of the tracking space of the remote Vive system.
This allows the HoloLens user to place the virtual content of the server (content
of the HTC Vive side) to any place in his real environment. Additionally, this
approach also enables the user to synchronize the tracking spaces in the same
room by placing the marker on the origin of the Vive tracking system, as shown
in Figure 2a.
Our first tests showed that we can successful merge two different tracking
systems, such as the HTC Vive and the HoloLens, but we experienced some is-
sues: The tracking system of the Vive interferes with the tracking system of the
HoloLens as soon as the users approach closer than one meter to each other. It
lead to tracking errors for the HTC Vive. Furthermore, we experienced that the
HoloLens’ processing power is limited due relative low technical specifications
compared to a workstation which limits the complexity of the rendered scene.
Moreover, we have identified that even the local network connection in our col-
laboration scenario in the same room reveals delays which are noticeable and
could interfere with natural interaction, nonverbal cues and gestures.
5 Research Agenda, Technology Trends and Outlook
This paper has shown examples of remote collaboration which prove the per-
formance and potential of MR. Although important enhancements and research
results have been discovered in recent years, we still have a long way to go until
we have achieved the ultimate display for collaboration - Star Trek’s Holodeck.
A major concern of research, which up to this point has been scarcely inves-
tigated, is the collaboration between multiple teams. The focus in past research
has been mainly conducted on collaboration between two persons, but how to
exchange complex data and interact between multiple groups has yet to be re-
searched further. Lukosch et al. [17] have taken the first steps in this direction but
stated that further research is necessary. Piirainen, Kolfschoten and Lukosch [27]
mention that a difficulty of collaborative remote work in teams is developing a
consensus about the nature of the problem and specification. Situational Aware-
ness cues and Team Awareness cues need to be outlined.
Another important point on the agenda is how to maintain focus of the users
to certain events and parts in the environment. Awareness cues are in general an
ongoing topic of research and must be investigated further. M¨uller, R¨adle und
Reiterer [21] ascertain that a technique is needed to put events, collaborators or
objects into the users’ focus, which are not in the field of view. Pejsa et al. [26] and
Masai et al. [18] emphasize the importance of nonverbal communication cues such
as facial expression, posture and proxemics which are important contributors to
empathy but these cues are still difficult to transmit with today’s hardware.
A relative rarely investigated field of research is comfort in MR, though it is
an important area for the usage of an application over a long period of time. Up
to this point, a real use case could look like this: A worker conducts a demanding
assembly task for hours on an expensive machine by remote guidance. But the
weight of the HMD, the usability of the application and the fatigue in his arms
from making gestures for interacting with the device lead to a growing frustration
by the worker which lead, in turn, to errors of the assembling. Piirainen et al. [27]
advise not to underestimate user needs and human factors: ”From a practical
perspective the challenges show that the usability of systems is a key.” Today, a
general problem and consideration for every MR application is comfort for the
user. Only a few years ago, VR and AR hardware was used to be bulky and
heavy and research in regards of comfort was theoretically in vain. Research in
MR is mainly focused on technical feasibility and compares productivity between
non-MR and MR application. However, comfort and usability is important, if
long-term applications are required, but research of comfort is scarce. Ladwig,
Herder and Geiger [13] consider and evaluate comfort for MR application. Lubos
et al. [15] revealed important outcomes for comfortable interaction and did first
steps into this direction.
Moreover, perceiving virtual haptic is widely an unresolved problem in MR
and researcher tries to substitute it with the aid of constraints such as virtual
collisions and snapping, as Oda et al. shows [23]. Furthermore, Lukosch et al. [16]
and Billinghurst [4] mention that further research is needed which particular
tasks can be effectively solved and managed with MR.
Better tracking technologies, faster networks, enhanced sensors and faster
processing will move us to the Holodeck and maybe even beyond. Further areas of
research will arise with the advent of new technologies such as machine learning
for object detection and recognition. MR devices of the future will not only
recognize surfaces of the environment, but also detect objects such as machine
parts, tools and humans.
6 Design Guidelines
Past research and our lessons learned revealed many issues which can be con-
cluded into design guidelines for the development of MR applications:
Provide as much information about the remote environment as pos-
sible Video is a minimum requirement. A 3D mesh of the environment is bet-
ter [5,23, 28–31]. An updated 3D mesh in real-time seems to be the best case [35].
Provide an independent PoV for investigating the remote scenery It
allows better spatial p erception and problem understanding [1, 28, 29, 33, 35]
Provide as much Awareness Cues as possible Transmitting speech is fun-
damental. Information of posture of collaborators such as head position, head
gaze, eye gaze, FoV [28, 29] is beneficial. For pointing by hand is a virtual ray
sufficient but a static hand model [31] or even a full tracked hand model is
better and conveys more information such as natural gestures [28,29]. Provide
cues for events happen outside the FoV of the users and provide Shared Local
Landmarks [21]. To avoid cluttering the view of the users, awareness cues can
be turned on and off [21].
Consider usability and comfort If a long-term usage is desired, take a com-
fortable interface for the user into account and consider human factors [13,15,27].
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... MR has seen a surge in its popularity in the last decade due to advances in portable mobile devices and computer vision [14,29]. Ladwig and Geiger [18] consider how the advancement of MR technology in the near future will allow us to create the "ultimate device" that will be capable of making the real world indistinguishable from the virtual world. Such a system would provide "realistic and complete embodied experiences" by utilizing multiple human sensory modalities including haptic, sound or even smell and taste [18]. ...
... Ladwig and Geiger [18] consider how the advancement of MR technology in the near future will allow us to create the "ultimate device" that will be capable of making the real world indistinguishable from the virtual world. Such a system would provide "realistic and complete embodied experiences" by utilizing multiple human sensory modalities including haptic, sound or even smell and taste [18]. ...
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Smart environments, comprised of networked embedded devices, improve the lives of their users by providing them with a variety of assistive services that traditional built environments are incapable of supporting. However, as the number of connected devices in smart environments continue to increase, so does the level of complexity involved in interacting with these environments. Traditional human-computer interaction techniques are not always well-suited for smart environments and this poses some unique usability challenges. To facilitate interactions within such technology-rich smart environments, new models and interaction interfaces need to be developed. In this paper we propose a multi-modal approach to smart environment interaction and explore two novel interaction interfaces: gesture-based interface and mixed-reality-based interface. We also conducted a user study to compare the learnability, efficiency and memorability of these new interfaces to two more commonly used interfaces: voice-based interface and a smartphone GUI-based interface. Our user study experiment involved four light control tasks that subjects were asked to complete using the four interaction interfaces. Study subjects found different interaction techniques to be more suitable for different tasks based on the type, complexity and context of the task. Our analysis of the study results and subject feedback suggest that a multi-modal approach is preferable to a uni-modal approach for interacting with smart environments. We suggest that novel interaction techniques be further explored in order to develop efficient multi-modal approaches along with the widely used techniques.
... In 2012, the concept of AR remote maintenance (referred to as AR-assisted maintenance system) was mentioned for the first time in a literature review as a field of application [33]. In 2019 and 2020, a total of six literature reviews (three per year) that mention AR remote maintenance have been published indicating the increasing attention on this type of AR [4,[34][35][36][37][38]. ...
Conference Paper
Augmented reality (AR) is a promising technology for supporting industrial maintenance applications. Two major types of AR technology are used for maintenance applications. One of those is AR remote maintenance, a technology that connects remote experts to on-site technicians to work collaboratively on industrial maintenance applications. This seems especially valuable for nonstandardized tasks. Although several recent systematic literature reviews (SLRs) on AR for maintenance applications have been published, the growing body of literature calls for an ever-differentiated view of the knowledge base of AR remote maintenance. Therefore, this paper aims to map AR remote maintenance literature by conducting an SLR, characterizing the literature, describing applications in industry, and making suggestions for further research. Based on the analysis of 89 articles from the last two decades, this paper contributes the following findings: 1) the research field has a strong engineering focus on system development. 2) scholars share a common understanding of AR remote maintenance, despite using heterogeneous terminology; 3) the prevailing study design only allows for limited comparison of prototypes and applications; 4) transferability to industrial maintenance professionals is limited, due to the study design; 5) AR remote maintenance appears to raise business model opportunities for product-service systems; and 6) the diversity of AR remote maintenance applications indicates the technology’s industrial versatility. Overall, the maturity of the research field is increasing; however, it is still at an early stage. Based on these findings, we made two proposals for advancing the AR remote maintenance research field.KeywordsAugmented realityRemote maintenanceTele-assistanceMobile collaborationProduct-service system
... Those statements remain on a superficial level, for example, "Consider usability and comfort. If a long-term usage is desired, take a comfortable interface for the user into account and consider human factors" [85]. Even more specific formulations are stated without further detail: "Consider the natural viewing angle" [136]. ...
Conference Paper
Over the last decades, different kinds of design guides have beencreated to maintain consistency and usability in interactive system development. However, in the case of spatial applications, practitioners from research and industry either have difficulties finding them or perceive such guides as lacking relevance, practicability, and applicability. In this paper, we present the current state of scientific research and industry practice by investigating currently used design recommendations for MR system development. Through a literature review, we analyzed and compared 875 design recommendations for MR applications elicited from 89 scientific papers and from six industry practitioner’s documentations. In doing so, we identified differences regarding four key topics: Focus on MR unique design challenges, abstraction regarding devices and ecosystems, level of detail and abstraction of content, and covered topics. Based on that, we contribute to the MR design research by providing three factors for perceived irrelevance as well as six main implications for design recommendations that are applicable in scientific and industry practice.
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Research in Collaborative Virtual Environments (CVEs) is becoming more and more significant with increasing accessibility of Virtual Reality (VR) and Augmented Reality (AR) technology, additionally reinforced by the increasing demand for remote collaboration groupware. While the research is focusing on methods for synchronous remote collaboration, asynchronous remote collaboration remains a niche. Nevertheless, future CVEs should support both paradigms of collaborative work, since asynchronous collaboration has as well its benefits, for instance a more flexible time-coordination. In this paper we present a concept of recording and later playback of highly interactive collaborative tasks in Mixed Reality (MR). Furthermore, we apply the concept in an assembly training scenario from the manufacturing industry and test it during pilot user experiments. The pilot study compared two modalities, the first one with a manufacturing manual, and another using our concept and featuring a ghost avatar. First results revealed no significant differences between both modalities in terms of time completion, hand movements, cognitive workload and usability. Some differences were not expected, however, these results and the feedback brought by the participants provide insights to further develop our concept.KeywordsAsynchronous remote collaborationCollaborative Virtual EnvironmentsMixed RealityAsymmetric collaboration
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This paper discussed the background of crime scene investigations and reviewed a novel Augmented Reality Learning Environment for using HoloLens in crime scene investigation. It clarified the concepts of augmented reality (AR), and virtual reality (VR). With the advancement of technology, forensic investigation is compelled to adapt to corresponding changes and use them to its benefit. In addition, it reviews the extant literature on the use of HoloLens in crime scene investigation. Through this review, the research questions are being formulated for future perspectives of crime scene investigations through Augmented Reality.KeywordsCrime sceneForensicsAugmented Reality
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Jaw surgery is a challenging surgical technique to study, due to the small case numbers. Surgeons may never have real experience with the procedure. This causes delays in the critical procedures and may affect the patient’s speech development. Virtual reality (VR) is a great tool to simulate surgical operations. Previously, we introduced a virtual reality system for jaw surgery simulation. In this work, we performed an additional evaluation of our system to realize its limitation and improvable elements. Results show that its potential as a training tool is limited. Mainly due to the lack of collaborative interaction. Trainers outside of the VR environment can only communicate with VR users through verbal communication. However surgical techniques are impractical to teach via this method. To address this shortcoming, we surveyed works on collaborative features on virtual reality systems. Other proposed improvement features are advanced input devices and artificial intelligence. The improvements can lift the realism of the VR system.
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The COVID-19 pandemic has had a tremendous impact on businesses, educational institutions, and other organizations that require in-person gatherings. Physical gatherings such as conferences, classes, and other social activities have been greatly reduced in favor of virtual meetings on Zoom, Webex or similar video-conferencing platforms. However, video-conferencing is quite limited in its ability to create meeting spaces that capture the authentic feel of a real-world meeting. Without the aid of body language cues, meeting participants have a harder time paying attention and keeping themselves engaged in virtual meetings. Video-conferencing, as it currently stands, falls short of providing a familiar environment that fosters personal connection between meeting participants. This paper explores an alternative approach to virtual meetings through the use of extended reality (XR) and embodied interactions. We present an application that leverages the full-body tracking capabilities of the Azure Kinect and the immersive affordances of XR to create more vibrant and engaging remote meeting environments.
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Recent trends in Extended Reality technologies, including Virtual Reality and Mixed Reality, indicate that the future infrastructure will be distributed and collaborative, where end-users as well as experts meet, communicate, learn, interact with each other, and coordinate their activities using a globally shared network and meditated environments. The integration of new display devices has largely changed how users interact with the system and how those activities, in turn, change their perception and experience. Although a considerable amount of research has already been done in the fields of computer-supported collaborative work, human-computer interaction, extended reality, cognitive psychology , perception, and social sciences, there is still no in-depth review to determine the current state of research on multiple-user-experience-centred design at the intersection of these domains. This paper aims to present an overview of research work on coexperience and analyses important aspects of human factors to be considered to enhance collaboration and user interaction in collaborative extended reality platforms, including: (i) presence-related factors, (ii) group dynamics and collaboration patterns , (iii) avatars and embodied agents, (iv) nonverbal communication, (v) group size, and (vi) awareness of physical and virtual world. Finally, this paper identifies research gaps and suggests key directions for future research considerations in this multidisciplinary research domain.
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Analysing and manipulating 3D objects are key competences for product designers. Although there is a substantial amount of research on review tools based on immersive technologies related to industrial practices, a comparison with traditional design reviews on an educational level is less prominent in scientific literature. This paper consists of a comparison between reviewing a CAD model on a 2D laptop screen and a more immersive method, using an augmented reality (AR) headset. The participants are twelve industrial design students. They were asked to review two products and look for ergonomic and technical design errors. Based on the evaluation of different parameters, the presented AR method scored high on spatial insight and contextual readability. Also, it was uncovered that the AR method was more demanding both physically and mentally. The findings state that immersive technologies can positively influence the industrial design process, anticipating that future AR technology becomes mature enough.
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In this paper, we explore techniques for enhancing remote Mixed Reality (MR) collaboration in terms of communication and interaction. We created CoVAR, a MR system for remote collaboration between an Augmented Reality (AR) and Augmented Virtuality (AV) users. Awareness cues and AV-Snap-to-AR interface were proposed for enhancing communication. Collaborative natural interaction, and AV-User-Body-Scaling were implemented for enhancing interaction. We conducted an exploratory study examining the awareness cues and the collaborative gaze, and the results showed the benefits of the proposed techniques for enhancing communication and interaction.
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We present CoVAR, a novel remote collaborative system combining Augmented Reality (AR), Virtual Reality (VR) and natural communication cues to create new types of collaboration. AR user can capture and share their local environment with a remote user in VR to collaborate on spatial tasks in shared space. COVAR supports various interaction methods to enrich collaboration, including gestures, head gaze, and eye gaze input, and provides virtual cues to improve awareness of a remote collaborator. We also demonstrate collaborative enhancements in VR user's body scaling and snapping to AR perspective.
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HCI research has demonstrated Mixed Reality (MR) as being beneficial for co-located collaborative work. For remote collaboration, however, the collaborators' visual contexts do not coincide due to their individual physical environments. The problem becomes apparent when collaborators refer to physical landmarks in their individual environments to guide each other's attention. In an experimental study with 16 dyads, we investigated how the provisioning of shared virtual landmarks (SVLs) influences communication behavior and user experience. A quantitative analysis revealed that participants used significantly less ambiguous spatial expressions and reported an improved user experience when SVLs were provided. Based on these findings and a qualitative video analysis we provide implications for the design of MRs to facilitate remote collaboration.
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" In many complex tasks, a remote subject-matter expert may need to assist a local user to guide actions on objects in the local user's environment. However, effective spatial referencing and action demonstration in a remote physical environment can be challenging. We introduce two approaches that use Virtual Reality (VR) or Augmented Reality (AR) for the remote expert, and AR for the local user, each wearing a stereo head-worn display. Both approaches allow the expert to create and manipulate virtual replicas of physical objects in the local environment to refer to parts of those physical objects and to indicate actions on them. This can be especially useful for parts that are occluded or difficult to access. In one approach, the expert points in 3D to portions of virtual replicas to annotate them. In another approach, the expert demonstrates actions in 3D by manipulating virtual replicas, supported by constraints and annotations. We performed a user study of a 6DOF alignment task, a key operation in many physical task domains, comparing both approaches to an approach in which the expert uses a 2D tablet-based drawing system similar to ones developed for prior work on remote assistance. The study showed the 3D demonstration approach to be faster than the others. In addition, the 3D pointing approach was faster than the 2D tablet in the case of a highly trained expert.
Conference Paper
More than three decades of ongoing research in immersive modelling has revealed many advantages of creating objects in virtual environments. Even though there are many benefits, the potential of immersive modelling has only been partly exploited due to unresolved problems such as ergonomic problems, numerous challenges with user interaction and the inability to perform exact, fast and progressive refinements. This paper explores past research, shows alternative approaches and proposes novel interaction tools for pending problems. An immersive modelling application for polygon meshes is created from scratch and tested by professional users of desktop modelling tools, such as Autodesk Maya, in order to assess the efficiency, comfort and speed of the proposed application with direct comparison to professional desktop modelling tools.
Conference Paper
Designing spatial user interfaces for virtual reality (VR) applications that are intuitive, comfortable and easy to use while at the same time providing high task performance is a challenging task. This challenge is even harder to solve since perception and action in immersive virtual environments differ significantly from the real world, causing natural user interfaces to elicit a dissociation of perceptual and motor space as well as levels of discomfort and fatigue unknown in the real world. In this paper, we present and evaluate the novel method to leverage joint-centered kinespheres for interactive spatial applications. We introduce kinespheres within arm's reach that envelope the reachable space for each joint such as shoulder, elbow or wrist, thus defining 3D interactive volumes with the boundaries given by 2D manifolds. We present a Fitts' Law experiment in which we evaluated the spatial touch performance on the inside and on the boundary of the main joint-centered kinespheres. Moreover, we present a confirmatory experiment in which we compared joint-centered interaction with traditional spatial head-centered menus. Finally, we discuss the advantages and limitations of placing interactive graphical elements relative to joint positions and, in particular, on the boundaries of kinespheres.
Conference Paper
Room2Room is a life-size telepresence system that leverages projected augmented reality to enable co-present interaction between two remote participants. Our solution recreates the experience of a face-to-face conversation by performing 3D capture of the local user with color + depth cameras and projecting their virtual copy into the remote space at life-size scale. This creates an illusion of the remote person’s physical presence in the local space, as well as a shared understanding of verbal and non-verbal cues (e.g., gaze, pointing) as if they were there. In addition to the technical details of our two prototype implementations, we contribute strategies for projecting remote participants onto physically plausible seating or standing locations, such that they form a natural and consistent conversational formation with the local participant. We also present observations and feedback from an evaluation with 7 pairs of participants on the usability of our solution for solving a collaborative, physical task.
Conference Paper
In this paper, we describe Empathy Glasses, a head worn prototype designed to create an empathic connection between remote collaborators. The main novelty of our system is that it is the first to combine the following technologies together: (1) wearable facial expression capture hardware, (2) eye tracking, (3) a head worn camera, and (4) a see-through head mounted display, with a focus on remote collaboration. Using the system, a local user can send their information and a view of their environment to a remote helper who can send back visual cues on the local user's see-through display to help them perform a real world task. A pilot user study was conducted to explore how effective the Empathy Glasses were at supporting remote collaboration. We describe the implications that can be drawn from this user study.
Conference Paper
For operational units in the security domain that work together in teams it is important to quickly and adequately exchange context-related information. Currently, information exchange is based on oral communication only. This paper reports on different scenarios from the security domain in which augmented reality (AR) techniques are used to support such information exchange. The scenarios have been elicited using an end-user centred design approach. To support these scenarios an AR environment has been developed and the usability of the AR support has been evaluated with experts from different operational units in the security domain. The first evaluation shows that the scenarios are well defined and the AR environment can successfully support information exchange in teams operating in the security domain.