Understanding the immersive experience: Examining the influence of visual immersiveness and interactivity on spatial experiences and understanding

Advances in computer graphics have enabled us to generate more compelling 3D virtual environments. 'Immersive experience' in these environments result from a combination of immersion and interactivity. As such, various disciplines have started adopting 3D technology for enhancing spatial understanding and experience. But the impact of the immersive experience on spatial understanding and experience remains unclear. This study utilized a controlled, between-subjects experiment to systematically manipulate a virtual reality system's technology affordances (stereoscopy, field of view, and navigability) and measure their impact. Participants, N=120, explored a virtual office and completed a questionnaire on the experience and tasks evaluating their understanding of the space. The results indicated that visual immersion had the greatest impact on understanding but, better experiences were gained when visual immersion was combined with greater interactivity. These findings support the notion the immersive experience is important for the comprehension of virtual spaces. This study overall served to provide insight into the role of the immersive experience on the comprehension of virtual spaces. The findings advance theories of spatial presence and immersion, support the use of methods which look at technology as affordances rather than entities, and support the use of 3D technology for communicating spatial information as in the case of architecture and fire-fighter training

Influence of immersion on user's spatial presence and memory in virtual environments

This study examines the influence of immersion on users' sense of spatial presence and spatial memory in virtual environments. The single factor was systematically manipulated in three conditions. A sample of 32 participants was used to test the study hypotheses. This study employed a between-subject design, and participants were randomly assigned to one of the three experimental conditions. The results from statistical analysis of covariance (ANCOVA) revealed the influence of immersion on the spatial presence and spatial memory. The results of this study revealed that higher level of immersion including a wider field of view and the stereoscopic display did lead to a greater sense of presence and improved spatial memory performance. This study has practical implications across various domains including architectural design and visualization, developing virtual reality systems, and training simulators.Includes bibliographical reference

Optical techniques for 3D surface reconstruction in computer-assisted laparoscopic surgery

One of the main challenges for computer-assisted surgery (CAS) is to determine the intra-opera- tive morphology and motion of soft-tissues. This information is prerequisite to the registration of multi-modal patient-specific data for enhancing the surgeon’s navigation capabilites by observ- ing beyond exposed tissue surfaces and for providing intelligent control of robotic-assisted in- struments. In minimally invasive surgery (MIS), optical techniques are an increasingly attractive approach for in vivo 3D reconstruction of the soft-tissue surface geometry. This paper reviews the state-of-the-art methods for optical intra-operative 3D reconstruction in laparoscopic surgery and discusses the technical challenges and future perspectives towards clinical translation. With the recent paradigm shift of surgical practice towards MIS and new developments in 3D opti- cal imaging, this is a timely discussion about technologies that could facilitate complex CAS procedures in dynamic and deformable anatomical regions

SMART-I²: A Spatial Multi-users Audio-visual Real Time Interactive Interface

International audienceThe SMART-I2 aims at creating a precise and coherent virtual environment by providing users with both audio and visual accurate localization cues. It is known that for audio rendering, Wave Field Synthesis, and for visual rendering, Tracked Stereoscopy, individually permit high quality spatial immersion within an extended space. The proposed system combines these two rendering approaches through the use of a large Multi-Actuator Panel used as both a loudspeaker array and as a projection screen, considerably reducing audio-visual incoherencies. The system performance has been confirmed by an objective validation of the audio interface and a perceptual evaluation of the audio-visual rendering

Spatial cognition in virtual environments

Since the last decades of the past century, Virtual Reality (VR) has been developed also as a methodology in research, besides a set of helpful applications in medical field (trainings for surgeons, but also rehabilitation tools). In science, there is still no agreement if the use of this technology in research on cognitive processes allows us to generalize results found in a Virtual Environment (VE) to the human behavior or cognition in the real world. This happens because of a series of differences found in basic perceptual processes (for example, depth perception) suggest a big difference in visual environmental representation capabilities of Virtual scenarios. On the other side, in literature quite a lot of studies can be found, which give a proof of VEs reliability in more than one field (trainings and rehabilitation, but also in some research paradigms). The main aim of this thesis is to investigate if, and in which cases, these two different views can be integrated and shed a new light and insights on the use of VR in research. Through the many experiments conducted in the "Virtual Development and Training Center" of the Fraunhofer Institute in Magdeburg, we addressed both low-level spatial processes (within an "evaluation of distances paradigm") and high-level spatial cognition (using a navigation and visuospatial planning task, called "3D Maps"), trying to address, at the same time, also practical problems as, for example, the use of stereoscopy in VEs or the problem of "Simulator Sickness" during navigation in immersive VEs. The results obtained with our research fill some gaps in literature about spatial cognition in VR and allow us to suggest that the use of VEs in research is quite reliable, mainly if the investigated processes are from the higher level of complexity. In this case, in fact, human brain "adapts" pretty well even to a "new" reality like the one offered by the VR, providing of course a familiarization period and the possibility to interact with the environment; the behavior will then be “like if” the environment was real: what is strongly lacking, at the moment, is the possibility to give a completely multisensorial experience, which is a very important issue in order to get the best from this kind of “visualization” of an artificial world. From a low-level point of view, we can confirm what already found in literature, that there are some basic differences in how our visual system perceives important spatial cues as depth and relationships between objects, and, therefore, we cannot talk about "similar environments" talking about VR and reality. The idea that VR is a "different" reality, offering potentially unlimited possibilities of use, even overcoming some physical limits of the real world, in which this "new" reality can be acquired by our cognitive system just by interacting with it, is therefore discussed in the conclusions of this work

Spatial cognition in virtual environments

Since the last decades of the past century, Virtual Reality (VR) has been developed also as a methodology in research, besides a set of helpful applications in medical field (trainings for surgeons, but also rehabilitation tools). In science, there is still no agreement if the use of this technology in research on cognitive processes allows us to generalize results found in a Virtual Environment (VE) to the human behavior or cognition in the real world. This happens because of a series of differences found in basic perceptual processes (for example, depth perception) suggest a big difference in visual environmental representation capabilities of Virtual scenarios. On the other side, in literature quite a lot of studies can be found, which give a proof of VEs reliability in more than one field (trainings and rehabilitation, but also in some research paradigms). The main aim of this thesis is to investigate if, and in which cases, these two different views can be integrated and shed a new light and insights on the use of VR in research. Through the many experiments conducted in the "Virtual Development and Training Center" of the Fraunhofer Institute in Magdeburg, we addressed both low-level spatial processes (within an "evaluation of distances paradigm") and high-level spatial cognition (using a navigation and visuospatial planning task, called "3D Maps"), trying to address, at the same time, also practical problems as, for example, the use of stereoscopy in VEs or the problem of "Simulator Sickness" during navigation in immersive VEs. The results obtained with our research fill some gaps in literature about spatial cognition in VR and allow us to suggest that the use of VEs in research is quite reliable, mainly if the investigated processes are from the higher level of complexity. In this case, in fact, human brain "adapts" pretty well even to a "new" reality like the one offered by the VR, providing of course a familiarization period and the possibility to interact with the environment; the behavior will then be “like if” the environment was real: what is strongly lacking, at the moment, is the possibility to give a completely multisensorial experience, which is a very important issue in order to get the best from this kind of “visualization” of an artificial world. From a low-level point of view, we can confirm what already found in literature, that there are some basic differences in how our visual system perceives important spatial cues as depth and relationships between objects, and, therefore, we cannot talk about "similar environments" talking about VR and reality. The idea that VR is a "different" reality, offering potentially unlimited possibilities of use, even overcoming some physical limits of the real world, in which this "new" reality can be acquired by our cognitive system just by interacting with it, is therefore discussed in the conclusions of this work

Exploring the Potential of 3D Visualization Techniques for Usage in Collaborative Design

Best practice for collaborative design demands good interaction between its collaborators. The capacity to share common knowledge about design models at hand is a basic requirement. With current advancing technologies gathering collective knowledge is more straightforward, as the dialog between experts can be supported better. The potential for 3D visualization techniques to become the right support tool for collaborative design is explored. Special attention is put on the possible usage for remote collaboration. The opportunities for current state-of-the-art visualization techniques from stereoscopic vision to holographic displays are researched. A classification of the various systems is explored with respect to their tangible usage for augmented reality. Appropriate interaction methods can be selected based on the usage scenario

Perceptual effects of volumetric shading models in stereoscopic desktop-based environments

Throughout the years, many shading techniques have been developed to improve the conveying of information in Volume Visualization. Some of these methods, usually referred to as realistic, are supposed to provide better cues for the understanding of volume data sets. While shading approaches are heavily exploited in traditional monoscopic setups, no previous study has analyzed the effect of these techniques in Virtual Reality. To further explore the influence of shading on the understanding of volume data in such environments, we carried out a user study in a desktop-based stereoscopic setup. The goals of the study were to investigate the impact of well-known shading approaches and the influence of real illumination on depth perception. Participants had to perform three different perceptual tasks when exposed to static visual stimuli. 45 participants took part in the study, giving us 1152 trials for each task. Results show that advanced shading techniques improve depth perception in stereoscopic volume visualization. As well, external lighting does not affect depth perception when these shading methods are applied. As a result, we derive some guidelines that may help the researchers when selecting illumination models for stereoscopic rendering.Peer ReviewedPostprint (author's final draft

Use of Depth Perception for the Improved Understanding of Hydrographic Data

This thesis has reviewed how increased depth perception can be used to increase the understanding of hydrographic data First visual cues and various visual displays and techniques were investigated. From this investigation 3D stereoscopic techniques prove to be superior in improving the depth perception and understanding of spatially related data and a further investigation on current 3D stereoscopic visualisation techniques was carried out. After reviewing how hydrographic data is currently visualised it was decided that the chromo stereoscopic visualisation technique is preferred to be used for further research on selected hydrographic data models. A novel chromo stereoscopic application was developed and the results from the evaluation on selected hydrographic data models clearly show an improved depth perception and understanding of the data models

An immersive virtual reality task with physical movement for the assessment of spatial memory

Tesis por compendioLa Realidad Virtual (RV) aún no se ha explotado en la evaluación de la memoria espacial. Los sistemas actuales de RV para la evaluación de la memoria espacial incluyen interacción mediante el uso de dispositivos tradicionales (por ejemplo, pantallas y teclados). Este tipo de interacción clásica con el sistema es ineficaz porque la sensación de presencia del usuario es muy pobre. Si el usuario no tiene la sensación de "estar ahí" en el entorno virtual, es posible que la memoria espacial no se evalúe correctamente. Por tanto, desarrollar un sistema que permita a los participantes estar activos en el entorno virtual, podría evaluar la memoria espacial de la misma forma que se puede evaluar en un entorno real. El objetivo principal de esta tesis fue diseñar, desarrollar y validar un sistema inmersivo de RV en el que el usuario pueda interactuar mediante movimiento físico. El entorno virtual se diseñó a partir de una ciudad con forma cuadrada. La tarea cognitiva, basada en dicho entorno, constaba de seis niveles. El objetivo de los niveles para la tarea principal era evaluar la memoria a corto plazo de los niños para la localización de objetos en el entorno virtual. El sistema de RV incorporó dos tipos de interacción. 1) Una condición física activa (caminar físicamente sobre una Wii Balance Board y cambiar la dirección girando un volante inalámbrico). 2) Una condición inactiva (estando de pie y usando un gamepad). Para la visualización de la tarea, se utilizó una pantalla grande y estéreo. Para la validación, se realizaron dos estudios (N=212). El rendimiento de nuestra tarea se comparó con métodos tradicionales. Se encontraron correlaciones entre nuestra tarea y los métodos tradicionales, lo que indica que nuestra tarea ha demostrado ser una herramienta válida para evaluar la memoria espacial a corto plazo en niños. Con respecto al tipo de interacción, los resultados mostraron que no hubo diferencias estadísticamente significativas con respecto a la puntuación obtenida en nuestra tarea y en función de la interacción utilizada. Éste es un buen resultado porque significa que la tarea es adecuada para la evaluación de la memoria espacial y que los dos tipos de interacción se pueden utilizar para este fin. Con respecto a las diferencias de género en la puntuación de la tarea y Corsi Block Tapping Test, los resultados indicaron que no hubo diferencias estadísticamente significativas para el género. Con respecto a facilidad de uso y satisfacción, se demostró que el uso de la condición inactiva no difirió significativamente de la condición física activa para las preguntas de usabilidad y satisfacción. Previamente al desarrollo del sistema de RV mencionado, desarrollamos un sistema de RV, con interfaces de usuario naturales (NUI) y una pantalla autoestereoscópica, para aprendizaje dental. El sistema incluye dos modos: fondo neutro y mundo real. Este sistema fue validado con 33 estudiantes. Con este primer desarrollo, se adquirió el conocimiento necesario para poder afrontar el segundo desarrollo, núcleo de la tesis. Las siguientes conclusiones generales se extrajeron de los 2 desarrollos y los 3 estudios: Aprendizaje - Los sistemas de RV con autoestereoscopía, con diferentes fondos y NUI, han demostrado ser herramientas eficaces para aprender la morfología dental - Con este tipo de sistemas, los niños pueden aprender y, al mismo tiempo, pueden divertirse - La estereoscopía y NUI son apropiadas para el desarrollo de juegos educativos y pueden ser explotadas en su desarrollo Memoria espacial - Los sistemas de RV, con estereoscopía y dos interfaces de usuario diferentes, han demostrado ser herramientas fiables y efectivas para evaluar la memoria espacial en niños - Con este tipo de sistemas, los niños pueden ser evaluados mientras se divierten - Nuestra tarea y tareas similares podrían usarse para evaluación y entrenamiento de la memoria en niños y adultosLa Realitat Virtual (RV) encara no s'ha explotat en l'avaluació de la memòria espacial. Els sistemes actuals de RV per a l'avaluació de la memòria espacial inclouen interacció mitjançant l'ús de dispositius tradicionals (per exemple, pantalles, ratolins o teclats). Aquest tipus d'interacció clàssica amb el sistema és ineficaç perquè la sensació de presència de l'usuari és molt pobre. Si l'usuari no té la sensació de "ser-hi" en l'entorn virtual, és possible que la memòria espacial no siga avaluada correctament. Per tant, desenvolupar un sistema que permeta als participants estar actius en l'entorn virtual, podria avaluar la memòria espacial de la mateixa manera que es pot avaluar en un entorn real. L'objectiu principal d'aquesta tesi va ser dissenyar, desenvolupar i validar un sistema immersiu de RV en el qual l'usuari puga interactuar mitjançant moviment físic. L'entorn virtual es va dissenyar a partir d'una ciutat amb forma quadrada. La tasca cognitiva constava de sis nivells. L'objectiu dels nivells per a la tasca principal era avaluar la memòria a curt termini dels xiquets per a la localització d'objectes en l'entorn virtual. El sistema de RV va incorporar dos tipus d'interacció. 1) Una condició física activa (caminar físicament sobre una Wii Balance Board i canviar la direcció girant un volant inalàmbric). 2) Una condició inactiva (estar dret i fent servir un gamepad). Per a la visualització de la tasca, es va utilitzar una pantalla gran i estèreo. Per a la validació, es van realitzar dos estudis (N=212). El rendiment de la nostra tasca es va comparar amb mètodes tradicionals. Es van trobar correlacions entre la nostra tasca i els mètodes tradicionals, el que indica que la nostra tasca ha demostrat ser una eina vàlida per avaluar la memòria espacial a curt termini en xiquets. Pel que fa al tipus d'interacció, els resultats van mostrar que no hi va haver diferències estadísticament significatives respecte a la puntuació obtinguda en la nostra tasca i en funció de la interacció utilitzada. Aquest és un bon resultat perquè significa que la tasca és adequada per a l'avaluació de la memòria espacial i que els dos tipus d'interacció es poden utilitzar per a aquest fi. Pel que fa a les diferències de gènere en la puntuació de la tasca i Corsi Block Tapping Test, els resultats van indicar que no hi va haver diferències estadísticament significatives per al gènere. Pel que fa a facilitat d'ús i satisfacció, els nostres estudis han demostrat que l'ús de la condició inactiva no va diferir significativament de la condició física activa per a les preguntes d'usabilitat i satisfacció. Prèviament al desenvolupament del sistema de RV esmentat, vam desenvolupar un sistema de RV, amb interfícies d'usuari naturals (NUI) i una pantalla autoestereoscòpica, per aprenentatge dental. El sistema inclou dos tipus de fons: fons neutre i món real. Aquest sistema va ser validat amb 33 estudiants. Amb aquest primer desenvolupament, es va adquirir el coneixement necessari per poder afrontar el segon desenvolupament, nucli de la tesi. Les següents conclusions generals es van extraure dels dos desenvolupaments i els tres estudis: Aprenentatge - Els sistemes de RV amb autoestereoscòpia, amb diferents fons i NUI, han demostrat ser eines eficaces per a aprendre la morfologia dental - Amb aquest tipus de sistemes, els xiquets poden aprendre i, al mateix temps, poden divertir-se - La estereoscòpia i NUI són apropiades per al desenvolupament de jocs educatius i poden ser explotades en el seu desenvolupament Memòria espacial - Els sistemes de RV, amb estereoscòpia i dues interfícies d'usuari diferents, han demostrat ser eines fiables i efectives per avaluar la memòria espacial en xiquets - Amb aquest tipus de sistemes, els xiquets poden ser avaluats mentre es diverteixen - La nostra tasca i tasques similars podrien usar-se per avaluació i entrenament de la memòria en xiquet i adultsVirtual Reality (VR) has not yet been exploited in the assessment of spatial memory. Current VR systems for the assessment of spatial memory include interaction by using traditional devices (e.g., computer screens, mouses or keyboards). This classical type of interaction with the system is ineffective because the user's sense of presence is very poor. If the user does not have the feeling of "being there" in the virtual environment, the spatial memory may not be assessed correctly. The user's physical movement can contribute to a high level of presence. Therefore, by developing a system that allows the participants to become active in a virtual environment, spatial memory can be assessed as the same way it could be evaluated in a real environment. The main objective of this thesis was to design, develop and validate an immersive VR system in which the user could interact by physical movements. The virtual environment was designed based on a city square. The cognitive task, based on this environment, comprised six levels. The goal of the levels for the main task was to assess children short-term memory for object location in the virtual environment. The VR system incorporated two types of interaction. 1) A physical active condition (physically walking on a Wii Balance Board and changing the direction by turning a wireless steering wheel). 2) An inactive condition (stand up and use a gamepad). For the visualization of the task, a large stereo screen was used. For the validation, two studies were carried out. The performance of our task was compared with traditional methods (the Corsi Block Tapping Test). We carried out two studies involving 212 children. Correlations were found between our task and traditional methods, indicating that our task has proven to be a valid tool for assessing spatial short-term memory in children. With regard to the interaction type, the results showed that there were no statistically significant differences regarding the score obtained in our task based on the interaction used (inactive condition vs. physical active condition). Although unexpected, this is a good result because it means that the task is well suited for the assessment of spatial memory and that the two interaction types can be used for this purpose. With regard to gender differences in the task score and the Corsi Block Tapping Test, the results indicated that there were no statistically significant differences for gender. With regard to usability and satisfaction, our studies have shown that the use of the inactive condition did not differ significantly from the physical active condition for the usability and satisfaction questions. Previously to the development of the mentioned VR system, we developed a VR system, with Natural User Interfaces (NUI) and an autostereoscopic screen, for dental learning. The system included two modes: neutral and real world background. This system was validated with 33 dentistry students. With this first development, the required knowledge for facing the second development, core of the thesis, was acquired. The following general conclusions were extracted from the two developments and the three studies: Learning - Autostereoscopic VR systems, with different background modes and NUI, have proven to be effective tools for learning teeth morphology - With this type of systems, children can learn and at the same time, they can have a good time - Stereoscopy and NUI are appropriated for developing educational games and they can be exploited in their development Spatial memory - VR systems, with stereoscopy and two different user interfaces (inactive and physical active conditions), have proven to be reliable and effective tools to assess spatial memory in children - With this type of systems, the children can be assessed meanwhile are having a good time - Our task and similar tasks could be used for assessment and training of spatial memory in children and adultsRodríguez Andrés, D. (2018). An immersive virtual reality task with physical movement for the assessment of spatial memory [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/114823TESISCompendi