Kristopher J. Blom

Virtual collision notification

Virtual collisions are reportedly an important part of creating effective experiences of virtual environments. Although they are considered vital, collision responses for travel in a virtual environment are not well understood. The effectivity of methods for notifying users of collisions has not been explored in the context of travel and the methods used are often not even reported. We present novel notification methods, based on haptic feedback via an output device embedded in the floor of our display and an initial study that compares nine notification methods. In a comparative study, our haptic floor feedback methods were preferred, followed by a thump sound and a wand device rumble. The results indicate that methods that are context appropriate, e.g. haptic responses and audio cues similar to real collisions with the object, are clearly preferable for realistic impressions of a world and of collisions.

Supporting the creation of dynamic, interactive virtual environments

Virtual Realitys expanding adoption makes the creation of more interesting dynamic, interactive environments necessary in order to meet the expectations of users accustomed to modern computer games. In this paper, we present initial explorations of using the recently developed Functional Reactive Programming paradigm to support the creation of such environments. The Functional Reactive Programming paradigm supports these actions by providing tools that match both the users perception of the dynamics of the world and the underlying hybrid nature of such environments. Continuous functions with explicit time dependencies describe the dynamic behaviors of the environment and discrete event mechanisms provide for modifying the active behaviors of the environment. Initial examples show how this paradigm can be used to control dynamic, interactive Virtual Environments.

ACTIF: an interactor centric interaction framework

The design and implementation of interactions in 3D environments remains a challenge. This is especially true for novices. Mechanisms to support the creation of interaction have been developed, but they lack a central metaphor that fits the natural way in which developers conceptualize interaction techniques. In this paper, we introduce a new framework whose design mirrors the essence of interaction throughout the Virtual Reality spectrum, where the user is literally in the center. It also reflects the way in which interactions are actually understood and described, based on the interactor and her actions. Based on the central metaphor of the interactor, an implementation that is composed of three phases is developed. Those phases are: input retrieval and shaping, interpretation of user intentions, and execution of changes to the environment. Through these divisions, software requirements like composition and reusability of components are satisfied. The resultant system ACTIF, an ACTor centric Interaction Framework, structures interaction development in a meaningful and understandable way and at the same time eases the design and creation of new and experimental interactions.

Functional Reactive Virtual Reality

In this paper we introduce a VR system extension that focuses on the creatio n of interactive, dynamic Virtual Environments. The extension uses the recently developed programming co ncept, Functional Reactive Programming. This paradigm focuses on an explicit and more natural concept of time in th e modeling of dynamics, without sacrificing interactivity. We present an implementation that embeds the Functiona l Reactive Programming concept into a basic Virtual Reality system, VR Juggler.

The design space of dynamic interactive virtual environments

Virtual environments have become a key component of many fields and the critical component of virtual reality applications. Due to their virtual nature, they can accommodate an infinite number of possibilities. A theoretical work is presented, which decomposes those innumerous possibilities into concepts to help clarify the vast design space and provide insights into future applied research. We propose that what makes environments interesting and engaging is having worlds that are both active and reactive. This article explores the manifestations of those actions and reactions in what we term: dynamic components and interactions. We term worlds containing these dynamic interactive virtual environments (DIVE). An analysis of each component time was performed, with the purpose of providing a theoretical understanding of the respective design spaces. Initially, we collected the myriad possibilities of each component, e.g., the possible kinds of interactions. We point to examples throughout the field to ground and explain concepts presented. We then categorized of each area into taxonomies. The result of the analyses provides insights into the design space of virtual environments, exposes several avenues of research that are yet underexplored, and provides better understandings of ways in which DIVE creation can be supported.

Floor-based Audio-Haptic Virtual Collision Responses

Virtual collisions are considered an important aspect of creating effective travel interactions for virtual environments; yet, they are not yet well understood. We introduce a new floor based audio-haptic interface for providing virtual collision feedback, the soundfloor. With this device, haptic feedback can be provided through the floor of a projection VR system, without disturbing the visual presentation on the same floor. As the impact of feedback is not yet known for virtual travel, we also present a series of experiments that compare different feedback methods coupled with classic collision handling methods. The results of the experiments show only limited benefits of collision handling and of additional feedback for performance. However, user preference of context appropriate feedback is evident, as well as a preference for the floor based haptic feedback. The experiments provide evidence of best practices for handling virtual travel collisions, namely that context appropriate feedback should be preferred and that quality sounds are sufficient when haptics cannot be provided.

Teaching, Exploring, Learning—Developing Tutorials for In‐Class Teaching and Self‐Learning

This paper presents an experience report on a novel approach for a course on intermediate and advanced computer graphics topics. The approach uses Teachlet Tutorials, a combination of traditional seminar–type teaching with interactive exploration of the content by the audience, plus development of self‐contained tutorials on the topic. In addition to a presentation, an interactive software tool is developed by the students to assist the audience in learning and exploring the topics details. This process is guided through set tasks. The resulting course material is developed for two different contexts: (a) for classroom presentation and (b) as an interactive, self‐contained, self‐learning tutorial. The overall approach results in a more thorough understanding of the topic both for the student teachers as well as for the class participants. In addition to detailing the Teachlet Tutorial approach, this paper presents our experiences implementing the approach in our Advanced Computer Graphics course and presents the resultant projects. Most of the final Teachlet Tutorials were surprisingly good and we had excellent feedback from the students on the approach and course.