SIAT Faculty Publications

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Is Seeing a Virtual Environment Like Seeing the Real Thing?

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2009
Abstract: 

Immersive virtual environments (IVE) are increasingly used in both fundamental research like experimental psychology and applications such as training, phobia therapy, or entertainment. Ideally, people should be able to perceive and behave in such IVEs as naturally and effectively as in real environments – especially if real-world transfer is desired. Being inherently mobile species, enabling natural spatial orientation and cognition in IVEs is essential. Here, we investigated whether seeing a virtual environment has a similar effect on our spatial cognition and mental spatial representation as a comparable real-world stimulus does – if it does not, how could we assume real-world transfer?

Document type: 
Article
File(s): 

Process Drama in the Virtual World - A Survey

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2008
Abstract: 

Process drama is a form of improvisational drama where the focus is on the process rather than the product. This form of improvisational activities has been used extensively in many domains. Role play, for example, has been used in health therapy as well as for training health personnel. Creative drama is a form of process drama that focuses on the use of story dramatization techniques; it has been extensively used to promote language and literature skills as well as creative and critical thinking. In these domains process drama exhibit itself in physical space. Recently, there have been many advances in technology that allows process drama to be exhibited in virtual space. In this article, we look at the form and structure of process drama. We specifically discuss process drama, especially Creative Drama. We outline several key factors of process drama that affect its effectiveness as a learning vehicle, including involvement and reflection. Through this lens, we survey several cases of virtual process drama both as a single person experience as well as a multiuser internet-based virtual experience.

Document type: 
Article
File(s): 

Interaction, Narrative, and Drama Creating an Adaptive Interactive Narrative using Performance Arts Theories

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2007
Abstract: 

Interactive narratives have been used in a variety of applications, including video games, educational games, and training simulations. Maintaining engagement within such environments is an important problem, because it affects entertainment, motivation, and presence. Performance arts theorists have discussed and formalized many techniques that increase engagement and enhance dramatic content of art productions. While constructing a narrative manually, using these techniques, is acceptable for linear media, using this approach for interactive environments results in inflexible experiences due to the unpredictability of users? actions. Few researchers attempted to develop adaptive interactive narrative experiences. However, developing a quality interactive experience is largely an art process, and many of these adaptive techniques do not encode artistic principles. In this paper, I present a new interactive narrative architecture designed using a set of dramatic techniques that I formulated based on several years of training in film and theatre.

Document type: 
Article

Learning Through Game Modding

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2006-01
Abstract: 

There has been a recent increase in the number of game environments or engines that allow users to customize their gaming experiences by building and expanding game behavior. This article describes the use of modifying, or modding, existing games as a means to learn computer science, mathematics, physics, and aesthetic principles. We describe two exploratory case studies of game modding in classroom settings to illustrate skills learned by students as a result of modding existing games. We also discuss the benefits of learning computer sciences skills (e.g., 3D graphics/mathematics, event-based programming, software engineering, etc.) through large design projects and how game design motivates students to acquire and apply these skills. We describe our use of multiple game modding environments in our classes. In addition, we describe how different engines can be used to focus students on the acquisition of particular skills and concepts.

Document type: 
Article

Intelligent Lighting for Game Environments

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2005-03
Abstract: 

Lighting design is an important topic of game development. There are many functions that lighting assumes in game environments, including directing attention, establishing good action visibility, evoking emotions, setting atmosphere, and providing depth. Current lighting design techniques rely on static manually designed lighting, where designers set up the positions, angles, and colors for each light in a level. Game environments are dynamic and unpredictable; physical and narrative scene content, including character locations, tension, and narrative goals, change unpredictably in real time due to user interaction. Thus, current static techniques often do not adequately adapt to serve desired aesthetic and communicative functions or perceptual effects. Recently, Doom 3 incorporated dynamic real-time lighting and demonstrated many advantages of using real-time dynamic lighting in games, including heightening the emotional engagement and enhancing the overall interactive experience. However, the technique is scripted and tightly coupled to game content. In this article, we present ELE (Expressive Lighting Engine), an intelligent lighting system that automatically sets and adjusts scene lighting in real time to achieve aesthetic and communicative functions, including evoking emotions, directing visual focus, and providing visibility and depth. ELE operates as a separate system that interacts with game/graphics engines through a standard interface. In this article, we will discuss ELE and its interface with Unreal Tournament 2003. We will also present results showing ELE in action. These results show: the utility of real-time adaptive lighting in providing visual focus, setting atmosphere, evoking emotions, and establishing visibility during interaction in interactive environments; and acceleration in the development process due to the introduction of an automatic system for lighting that can be overridden by designers at a high level, thus eliminating the time-consuming process of setting individual light parameters for each level and scene.

Document type: 
Article

Spatialized Sound Influences Biomechanical Self-Motion Illusion ("Vection")

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2010
Abstract: 

Although moving auditory cues have long been known to induce self-motion illusions (“circular vection”) in blindfolded participants, little is known about how spatial sound can facilitate or interfere with vection induced by other non-visual modalities like biomechanical cues. To address this issue, biomechanical circular vection was induced in seated, stationary participants by having them step sideways along a rotating floor (“circular treadmill”) turning at 60 /s (see Fig. 1, top). Three research hypotheses were tested by comparing four different sound conditions in combination with the same biomechanical vection-inducing stimulus.

Document type: 
Article

Moving Sounds Enhance the Visually-Induced Self-Motion Illusion (Circular Vection) in Virtual Reality

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2009-03
Abstract: 

While rotating visual and auditory stimuli have long been known to elicit self-motion illusions (“circular vection”), audiovisual interactions have hardly been investigated. Here, two experiments investigated whether visually induced circular vection can be enhanced by concurrently rotating auditory cues that match visual landmarks (e.g., a fountain sound). Participants sat behind a curved projection screen displaying rotating panoramic renderings of a market place. Apart from a no-sound condition, headphone-based auditory stimuli consisted of mono sound, ambient sound, or low-/high-spatial resolution auralizations using generic head-related transfer functions (HRTFs). While merely adding nonrotating (mono or ambient) sound showed no effects, moving sound stimuli facilitated both vection and presence in the virtual environment. This spatialization benefit was maximal for a medium (20 degrees × 15 degrees) FOV, reduced for a larger (54 degrees × 45 degrees) FOV and unexpectedly absent for the smallest (10 degrees × 7.5 degrees) FOV. Increasing auralization spatial fidelity (from low, comparable to five-channel home theatre systems, to high, 5 degree resolution) provided no further benefit, suggesting a ceiling effect. In conclusion, both self-motion perception and presence can benefit from adding moving auditory stimuli. This has important implications both for multimodal cue integration theories and the applied challenge of building affordable yet effective motion simulators.

Document type: 
Article

A control strategy for a distributed power generation microgrid application with voltage and current controlled source converter

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2010-12
Abstract: 

This paper presents a pseudodroop control structure integrated within a microgrid system through distributed power generation (DPG) modules capable to function in off-grid islanded, genset-connected, and grid-connected modes of operation. System efficiency has an important role in order to harvest the maximum available renewable energy from dc or ac sources while providing power backup capability. A control strategy is proposed in off-grid islanded mode method based on the microgrid line-frequency control as agent of communication for energy control between the DPG modules. A critical case is where the ac load demand could be lower than the available power from the photovoltaic solar array, where the battery bank can be overcharged with unrecoverable damage consequences. The DPG voltage-forming module controls the battery charge algorithm with a frequency-generator function, and the DPG current source module controls its output current through a frequency-detection function. The physical installation between DPG modules is independent, since no additional communication wiring is needed between power modules, which represent another integration advantage within the microgrid-type application.

Document type: 
Article

Dynamic Intelligent Lighting for Directing Visual Attention in Interactive 3D Scenes

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2009
Abstract: 

Recent enhancements in real-time graphics have facilitated the design of high fidelity game environments with complex 3D worlds inhabited by animated characters. Under such settings, it is hard, especially for the untrained eyes, to attend to an object of interest. Neuroscience research as well as film and theatre practice identified several visual properties, such as contrast, orientation, and color that play a major role in channeling attention. In this paper, we discuss an adaptive lighting design system called ALVA (Adaptive Lighting for Visual Attention) that dynamically adjusts the lighting color and brightness to enhance visual attention within game environments using features identified by neuroscience, psychophysics, and visual design literature. We also discuss some preliminary results showing the utility of ALVA in directing player’s attention to important elements in a fast paced 3D game, and thus enhancing the game experience especially for non-gamers who are not visually trained to spot objects or characters in such complex 3D worlds.

Document type: 
Article
File(s): 

DigitalBeing – Using the Environment as an Expressive Medium for Dance

Date created: 
2008
Abstract: 

Dancers express their feelings and moods through gestures and body movements. We seek to extend this mode of expression by dynamically and automatically adjusting music and lighting in the dance environment to reflect the dancer’s arousal state. Our intention is to offer a space that performance artists can use as a creative tool that extends the grammar of dance. To enable the dynamic manipulation of lighting and music, the performance space will be augmented with several sensors: physiological sensors worn by a dancer to measure her arousal state, as well as pressure sensors installed in a floor mat to track the dancers’ locations and movements. Data from these sensors will be passed to a three layered architecture. Layer 1 is composed of a sensor analysis system that analyzes and synthesizes physiological and pressure sensor signals. Layer 2 is composed of intelligent systems that adapt lighting and music to portray the dancer’s arousal state. The intelligent on-stage lighting system dynamically adjusts on-stage lighting direction and color. The intelligent virtual lighting system dynamically adapts virtual lighting in the projected imagery. The intelligent music system dynamically and unobtrusively adjusts the music. Layer 3 translates the high-level adjustments made by the intelligent systems in layer 2 to appropriate lighting board, image rendering, and audio box commands. In this paper, we will describe this architecture in detail as well as the equipment and control systems used.

Document type: 
Article