Diego Monteiro 0001

dblp:304/9403-1 · also Diego Vilela Monteiro · DBLP profile ↗
← Back
16ranked-venue papers
6as first author
8since 2021 · last 2024
0000-0002-1570-3652ORCID · verified

Domains — the database's venue-derived domains; a paper can count in several

Graphics, computer vision, multimedia, augmented reality and games · 11 · 4 first-author · 5 since 2021Human-computer interaction and ubiquitous computing · 9 · 4 first-author · 6 since 2021Artificial intelligence and machine learning · 1 · 1 since 2021Applied, interdisciplinary, general and emerging computing · 1 · 1 first-author
YearPublicationVenuePosition
2024 Exploring the influence of audience familiarity on speaker anxiety and performance in virtual reality and real-life presentation contexts
abstract
Virtual reality (VR) offers immense freedom in the design of virtual instructional environments, but little guidance exists on how to capitalise on this freedom. This article reports on a study exploring how audience familiarity influences public speaking anxiety (PSA) and performance in a presentation speaking task in virtuo and in situ. Questionnaire instruments were used to gauge the PSA, motivation, focus, and self-confidence of 10 undergraduate students who each presented in four different audience conditions across VR and real life. Presentations were transcribed to identify features of performance, including utterance fluency, and speaking breadth and depth. Outcomes indicated that an audience of computer-generated agents resulted in less PSA than an audience of photorealistic people familiar to the speakers. Additionally, presenting to an audience of strangers in real life induced the most anxiety, but the performance features of articulation rate, disfluencies, and frequency of silent pauses were significantly improved in this condition. The main contribution of this study is to show that presentations directed at virtual audiences exhibit less fluent speech in non-native speakers than speeches to a real audience.
Alex James Barrett, Austin Pack, Diego Monteiro 0001, Hai-Ning Liang
Behav. Inf. Technol.3
2023 Real-Time Prediction of Simulator Sickness in Virtual Reality Games
abstract
Virtual reality (VR) technology has progressed rapidly and is used in various domains, particularly games. Simulator sickness (SS) still represents a significant problem for its wider adoption. The most common way to detect SS is using the simulator sickness questionnaire (SSQ). SSQ is a subjective measurement and is inadequate for real-time applications such as VR games. This research aims to develop a model to predict SS in real time using in-game characters’ movement and users’ eye motion data during gameplay in VR games. To achieve this, we designed an experiment to collect such data with three types of games. We trained a long short-term memory neural network with the eye-tracking and character movement data to predict SS. Our model can predict SS in real time with an accuracy of 83.4% for players who suffer from severe sensitivity to SS. Our results indicate that, in VR games, our model is an accurate and efficient method to predict SS in real time.
Jialin Wang 0002, Hai-Ning Liang, Diego Monteiro 0001, Wenge Xu, Jimin Xiao
IEEE Trans. Games3
2022 VRCockpit: Mitigating Simulator Sickness in VR Games Using Multiple Egocentric 2D View Frames
abstract
Virtual reality head-mounted displays (VR HMDs) have become a popular platform for gaming. However, simulator sickness (SS) is still an impediment to VR’s wider adoption, particularly in gaming. It can induce strong discomfort and impair players’ immersion, performance, and enjoyment. Researchers have explored techniques to mitigate SS. While these techniques have been shown to help lessen SS, they may not be applicable to games because they cannot be easily integrated into various types of games without impacting gameplay, immersion, and performance. In this research, we introduce a new SS mitigation technique, VRCockpit. VRCockpit is a visual technique that surrounds the player with four 2D views, one for each cardinal direction, that show 2D copies of the areas of the 3D environment around the player. To study its effectiveness, we conducted two different experiments, one with a car racing game, followed by a first-person shooter game. Our results show that VRCockpit has the potential to mitigate SS and still allows players to have the same level of immersion and gameplay performance.
Rongkai Shi, Diego Monteiro 0001, Nilufar Baghaei, Hai-Ning Liang
CoG3
2021 Evaluating Performance and Gameplay of Virtual Reality Sickness Techniques in a First-Person Shooter Game
abstract
In virtual reality (VR) games, playability and immersion levels are important because they affect gameplay, enjoyment, and performance. However, they can be adversely affected by VR sickness (VRS) symptoms. VRS can be minimized by manipulating users' perception of the virtual environment via the head-mounted display (HMD). One extreme example is the Teleport mitigation technique, which lets users navigate discretely, skipping sections of the virtual space. Other techniques are less extreme but still rely on controlling what and how much users see via the HMD. This research examines the effect on players' performance and gameplay of these mitigation techniques in fast-paced VR games. Our focus is on two types of visual reduction techniques. This study aims to identify specifically the trade-offs these techniques have in a first-person shooter game regarding immersion, performance, and VRS. The main contributions in this paper are (1) a deeper understanding of one of the most popular techniques (Teleport) when it comes to gameplay; (2) the replication and validation of a novel VRS mitigation technique based on visual reduction; and (3) a comparison of their effect on players' performance and gameplay.
Diego Monteiro 0001, Hai-Ning Liang, Huawei Tu, Henry Dub
CoG1
2021 Effect of Input-output Randomness on Gameplay Satisfaction in Collectable Card Games
abstract
Randomness is an important factor in games, so much so that some games rely almost purely on it for its outcomes and increase players' engagement with them. However, randomness can affect the game experience depending on when it occurs in a game, altering the chances of planning for a player. In this paper, we refer to it as “input-output randomness”. Input-output randomness is a cornerstone of collectable card games like Hearthstone, in which cards are drawn randomly (input randomness) and have random effects when played (output randomness). While the topic might have been commonly discussed by game designers and be present in many games, few empirical studies have been performed to evaluate the effects of these different kinds of randomness on the players' satisfaction. This research investigates the effects of input-output randomness on collectable card games across four input-output randomness conditions. We have developed our own collectable card game and experimented with the different kinds of randomness with the game. Our results suggest that input randomness can significantly impact game satisfaction negatively. Overall, our results present helpful considerations on how and when to apply randomness in game design when aiming for players' satisfaction.
Yiwen Zhang 0007, Diego Monteiro 0001, Hai-Ning Liang, Jieming Ma, Nilufar Baghaei
CoG2
2021 Design and Development of a Low-cost Device for Weight and Center of Gravity Simulation in Virtual Reality
abstract
With rapid advances in virtual reality (VR) technology, the use of haptics has become important to allow users to feel the physical properties of virtual objects. Current research has focused mainly on either weight variation or changing the center of gravity, which limits the simulation potential and may affect the feeling of immersion. This research explores the design and development of a device that can simulate both weight and center of gravity using low-cost components. Through an iterative design process and continuous testing with users, we arrived at a final prototype, FluidWeight, a device that can be attached to a typical VR handheld controller. FluidWeight uses fluid, which is transported from a central storage to a receptacle attached to the controller. A final experiment shows that users enjoyed using it because it could help increase the sense of realism in VR applications.
Diego Monteiro 0001, Hai-Ning Liang, Wenge Xu, Huawei Tu
ICMI1
2021 Using Trajectory Compression Rate to Predict Changes in Cybersickness in Virtual Reality Games
abstract
Identifying cybersickness in virtual reality (VR) applications such as games in a fast, precise, non-intrusive, and non-disruptive way remains challenging. Several factors can cause cybersickness, and their identification will help find its origins and prevent or minimize it. One such factor is virtual movement. Movement, whether physical or virtual, can be represented in different forms. One way to represent and store it is with a temporally annotated point sequence. Because a sequence is memory-consuming, it is often preferable to save it in a compressed form. Compression allows redundant data to be eliminated while still preserving changes in speed and direction. Since changes in direction and velocity in VR can be associated with cybersickness, changes in compression rate can likely indicate changes in cybersickness levels. In this research, we explore whether quantifying changes in virtual movement can be used to estimate variation in cybersickness levels of VR users. We investigate the correlation between changes in the compression rate of movement data in two VR games with changes in players’ cybersickness levels captured during gameplay. Our results show (1) a clear correlation between changes in compression rate and cybersickness, and (2) that a machine learning approach can be used to identify these changes. Finally, results from a second experiment show that our approach is feasible for cybersickness inference in games and other VR applications that involve movement.
Diego Monteiro 0001, Hai-Ning Liang, Xiaohang Tang, Pourang Irani
ISMAR1
2021 Head-Mounted Display with Increased Downward Field of View Improves Presence and Sense of Self-Location
abstract
Common existing head-mounted displays (HMDs) for virtual reality (VR) provide users with a high presence and embodiment. However, the field of view (FoV) of a typical HMD for VR is about 90 to 110 [deg] in the diagonal direction and about 70 to 90 [deg] in the vertical direction, which is narrower than that of humans. Specifically, the downward FoV of conventional HMDs is too narrow to present the user avatar's body and feet. To address this problem, we have developed a novel HMD with a pair of additional display units to increase the downward FoV by approximately 60 ( 10+50) [deg]. We comprehensively investigated the effects of the increased downward FoV on the sense of immersion that includes presence, sense of self-location (SoSL), sense of agency (SoA), and sense of body ownership (SoBO) during VR experience and on patterns of head movements and cybersickness as its secondary effects. As a result, it was clarified that the HMD with an increased FoV improved presence and SoSL. Also, it was confirmed that the user could see the object below with a head movement pattern close to the real behavior, and did not suffer from cybersickness. Moreover, the effect of the increased downward FoV on SoBO and SoA was limited since it was easier to perceive the misalignment between the real and virtual bodies.
Kizashi Nakano, Naoya Isoyama, Diego Monteiro 0001, Nobuchika Sakata, Kiyoshi Kiyokawa, Takuji Narumi
IEEE Trans. Vis. Comput. Graph.3
2020 An In-Depth Exploration of the Effect of 2D/3D Views and Controller Types on First Person Shooter Games in Virtual Reality
abstract
The amount of interest in Virtual Reality (VR) research has significantly increased over the past few years, both in academia and industry. The release of commercial VR Head-Mounted Displays (HMDs) has been a major contributing factor. However, there is still much to be learned, especially how views and input techniques, as well as their interaction, affect the VR experience. There is little work done on First-Person Shooter (FPS) games in VR, and those few studies have focused on a single aspect of VR FPS. They either focused on the view, e.g., comparing VR to a typical 2D display or on the controller types. To the best of our knowledge, there are no studies investigating variations of 2D/3D views in HMDs, controller types, and their interactions. As such, it is challenging to distinguish findings related to the controller type from those related to the view. If a study does not control for the input method and finds that 2D displays lead to higher performance than VR, we cannot generalize the results because of the confounding variables. To understand their interaction, we propose to analyze in more depth, whether it is the view (2D vs. 3D) or the way it is controlled that gives the platforms their respective advantages. To study the effects of the 2D/3D views, we created a 2D visual technique, PlaneFrame, that was applied inside the VR headset. Our results show that the controller type can have a significant positive impact on performance, immersion, and simulator sickness when associated with a 2D view. They further our understanding of the interactions that controllers and views have and demonstrate that comparisons are highly dependent on how both factors go together. Further, through a series of three experiments, we developed a technique that can lead to a substantial performance, a good level of immersion, and can minimize the level of simulator sickness.
Diego Monteiro 0001, Hai-Ning Liang, Jialin Wang 0002, Nilufar Baghaei
ISMAR1
2019 DMove: Directional Motion-based Interaction for Augmented Reality Head-Mounted Displays
abstract
We present DMove, directional motion-based interaction for Augmented Reality (AR) Head-Mounted Displays (HMDs) that is both hands- and device-free. It uses directional walk-ing as a way to interact with virtual objects. To use DMove, a user needs to perform directional motions such as mov-ing one foot forward or backward. In this research, we first investigate the recognition accuracy of the motion direc-tions of our method and the social acceptance of this type of interactions together with users' comfort rating for each direction. We then optimize its design and conduct a sec-ond study to compare DMove in task performance and user preferences (workload, motion sickness, user experience), with two approaches-Hand interaction (Meta 2-like) and Head+Hand interaction (HoloLens-like) for menu selection tasks. Based on the results of these two studies, we provide a set of guidelines for DMove and further demonstrate two applications that utilize directional motions.
Wenge Xu, Hai-Ning Liang, Difeng Yu, Diego Monteiro 0001
CHI5
2019 Annotation vs. Virtual Tutor: Comparative Analysis on the Effectiveness of Visual Instructions in Immersive Virtual Reality
abstract
In this paper we present a comparative study of visual instructions in Immersive Virtual Reality (IVR), i.e., annotation (ANN) that employs 3D texts and objects for instructions and virtual tutor (TUT) that demonstrates a task with a 3D character. The comparison is based on three tasks, maze escape (ME), stretching exercise (SE), and crane manipulation (CM), defined by the types of a unit instruction. We conducted an automated evaluation of user's memory recall performances (recall time, accuracy, and error) by mapping a sequence of user's behaviors and events as a string. Results revealed that ANN group showed significantly more accurate performance (1.3 times) in ME and time performance (1.64 times) in SE than TUT group, while no statistical main difference was found in CM. Interestingly, although ANN showed statistically shorter execution time, the recalling time pattern of TUT group showed a steep convergence after initial trial. The results can be used in the field in terms of informing designers of IVR on what types of visual instruction are best for different task purpose.
Hyeopwoo Lee, Diego Monteiro 0001, Youngnoh Goh, Daseong Han, Hai-Ning Liang, Hyun Seung Yang, Jinki Jung
ISMAR3
2019 RingText: Dwell-free and hands-free Text Entry for Mobile Head-Mounted Displays using Head Motions
abstract
In this paper, we present a case for text entry using a circular keyboard layout for mobile head-mounted displays (HMDs) that is dwell-free and does not require users to hold a dedicated input device for letter selection. To support the case, we have implemented RingText whose design is based on a circular layout with two concentric circles. The outer circle is subdivided into regions containing letters. Selection is made by using a virtual cursor controlled by the user's head movements-entering a letter region triggers a selection and moving back into the inner circle resets the selection. The design of RingText follows an iterative process, where we initially conduct one first study to investigate the optimal number of letters per region, inner circle size, and alphabet starting location. We then optimize its design by selecting the most suitable features from the first study: one letter per region, narrowing the trigger area to lower error rates, and creating candidate regions that incorporate two suggested words to appear next to the current letter region (close to the cursor) using a dynamic (rather than fixed) approach. Our second study compares text entry performance of RingText with four other hands-free techniques and the results show that RingText outperforms them. Finally, we run a third study lasting four consecutive days with 10 participants (5 novice users and 5 expert users) doing two daily sessions and the results show that RingText is quite efficient and yields a low error rate. At the end of the eighth session, the novice users can achieve a text entry speed of 11.30 WPM after 60 minutes of training while the expert (more experienced) users can reach an average text entry speed of 13.24 WPM after 90 minutes of training.
Wenge Xu, Hai-Ning Liang, Difeng Yu, Diego Monteiro 0001
IEEE Trans. Vis. Comput. Graph.6
2019 Errata to "RingText: Dwell-Free and Hands-Free Text Entry for Mobile Head-Mounted Displays Using Head Motions"
abstract
Presents corrections to author information for the paper, “RingText: Dwell-Free and Hands-Free Text Entry for Mobile Head-Mounted Displays Using Head Motions,” (Xu, W., et al), IEEE Trans. Vis. Comput. Graph., vol. 25, no. 5, pp. 1991–2001, May 2019.
Wenge Xu, Hai-Ning Liang, Difeng Yu, Diego Monteiro 0001
IEEE Trans. Vis. Comput. Graph.6
2018 Evaluating enjoyment, presence, and emulator sickness in VR games based on first- and third- person viewing perspectives
abstract
Abstract Many virtual reality (VR) games are based on a first‐person perspective (1PP). There are, however, advantages in using another perspective, such as the third‐person perspective (3PP). Although there has been some research evaluating the effect of 1PP and 3PP in gameplay experiences, it is largely unexplored for VR games played via the new generation of commercial head‐mounted display systems, such as the Oculus Rift. In this research we want to shed some light on the relationship between the different perspectives, when games are played using head‐mounted display VR, and simulator sickness, enjoyment, and presence. To do so, we perform an experiment using two different perspectives (1PP and 3PP) and displays (VR and a conventional display) with a popular game. Our findings indicate that 3PP‐VR is less likely to make people have simulator sickness when compared with 1PP‐VR. However, the former is not perceived as immersive, but this might not be a problem because our data also show that presence is not mandatory for enjoyment. Also, the data suggest that there is no clear preference between 1PP‐VR and 3PP‐VR for gameplay.
Diego Monteiro 0001, Hai-Ning Liang, Wenge Xu, Marvin Brucker, Vijayakumar Nanjappan, Yong Yue 0001
Comput. Animat. Virtual Worlds1
2018 PizzaText: Text Entry for Virtual Reality Systems Using Dual Thumbsticks
abstract
We present PizzaText, a circular keyboard layout technique for text entry in virtual reality (VR) environments that uses the dual thumbsticks of a hand-held game controller. Text entry is a common activity in VR environments but remains challenging with existing techniques and keyboard layouts that is largely based on QWERTY. Our technique makes text entry simple, easy, and efficient, even for novice users. The technique uses a hand-held controller because it is still an important input device for users to interact with VR environments. To allow rapid search of characters, PizzaText divides a circle into slices and each slice contains 4 characters. To enable fast selection, the user uses the right thumbstick for traversing the slices, and the left thumbstick for choosing the letters. The design of PizzaText is based on three criteria: efficiency, learnability, and ease-of-use. In our first study, six potential layouts are considered and evaluated. The results lead to a design with 7 slices and 4 letters per slice. The final design is evaluated in a five-day study with 10 participants. The results show that novice users can achieve an average of 8.59 Words per Minute (WPM), while expert users are able to reach 15.85 WPM, with just two hours of training.
Difeng Yu, Kaixuan Fan, Diego Monteiro 0001, Wenge Xu, Hai-Ning Liang
IEEE Trans. Vis. Comput. Graph.4
2017 An Algorithm to Discover Partners in Trajectories
Diego Monteiro 0001, Karine Reis Ferreira, Rafael Duarte Coelho dos Santos
ICCSA (6)1