Benjamin Walther-Franks

Evaluation of an Augmented Photograph-Based Pedestrian Navigation System

Map interfaces are the quasi-standard for car navigation systems, and are usually the first choice for mobile pedestrian navigation systems. Alternatives are being investigated in research and industry that possibly suit the settings and needs of the person on foot better. One solution is augmented reality (AR), which blends navigation instructions with the view of the real world. However, research usually focuses too much on the technical implementation, leaving little time for a thorough assessment of the actual benefits of such a system. In this paper we present an evaluation of a mobile pedestrian navigation system prototype. The system provides a simplified augmented reality experience by presenting visually augmented photographs instead of a real-time video stream. We compare the usability of the AR interface with that of a map-based interface in a field evaluation. Our results challenge the map approach and suggest that AR is not only a serious alternative, but also potentially more suited for route presentation in PNS.

An unfinished drama: designing participation for the theatrical dance performance Parcival XX-XI

The partnership of theater and digital media shows much potential for new means of storytelling. Digital scenery can be joined to the performers action on stage; algorithmic influences can blur the linearity of a drama; interactive technology offers novel means of involving the audience in the creation of the piece. Interaction can thus enhance the dramaturgical possibilities of traditional theater. However, the narrative task also accompanies various new challenges for the designers of such a play. On the basis of our dance performance Parcival XX-XI, we define requirements for making an audience interact in a theatrical play and introduce four interaction-enabling criteria for theatrical performances that use gestural interfaces.

A multi-touch system for 3D modelling and animation

3D modelling and animation software is typically operated via single-pointer input, imposing a serialised workflow that seems cumbersome in comparison to how humans manipulate objects in the real world. Research has brought forth new interaction techniques for modelling and animation that utilise input with more degrees of freedom or employ both hands to allow more parallel control, yet these are separate efforts across diverse input technologies and have not been applied to a usable system. We developed a 3D modelling and animation system for multi-touch interactive surfaces, as this technology offers parallel input with many degrees of freedom through one or both hands. It implements techniques for one-handed 3D navigation, 3D object manipulation, and time control. This includes mappings for layered or multi-track performance animation that allows the animation of different features across several passes or the modification of previously recorded motion. We show how these unimanual techniques can be combined for efficient bimanual control and propose techniques that specifically support the use of both hands for typical tasks in 3D editing. A study proved that even inexperienced users can successfully use our system for a more parallel and direct modelling or animation process.

Exercise My Game: Turning Off-The-Shelf Games into Exergames

Exercise video games (exergames) can motivate players to be more physically active. However, most exergames are controlled by confined and predefined movements and do not promote long-term motivation. Well-funded commercial games often excel at long-term motivation, but are not operated with motion input. Exercise My Game (XMG) is a design framework for turning off-the-shelf action games into full-body motion-based games. Challenges with this approach involve finding mappings from control input to game-action, as well as blending active input feedback with the game’s interface. XMG facilitates transforming well-produced, non-exercise video games into captivating exergames by structuring the design space and outlining game requirements. We illustrate XMG with the example of turning the popular first-person action game Portal 2 into the exergame Sportal.

Suspended Walking: A Physical Locomotion Interface for Virtual Reality

We present a novel physical locomotion interface for virtual environments. It suspends the user in a torso harness so that the feet just touch ground. Low friction materials allow walking motions with ground contact similar to real walking, while maintaining the user in the same position. We detail the hardware and motion tracking setup and outline results of a first user study.

Integrated rotation and translation for 3d manipulation on multi-touch interactive surfaces

In the domain of 2D graphical applications multi-touch input is already quite well understood and smoothly integrated translation and rotation of objects widely accepted as a standard interaction technique. However, in 3D VR, modeling, or animation applications, there are no such generally accepted interaction techniques for multi-touch displays featuring the same smooth and fluid interaction style. In this paper we present two novel techniques for integrated 6 degrees of freedom object manipulation on multi-touch displays. They are designed to transfer the smooth 2D interaction properties provided by multi-touch input to the 3D domain. One makes separation of rotation and translation easier, while the other strives for maximum integration of rotation and translation. We present a first user study showing that while both techniques can be used successfully for unimanual and bimanual integrated 3D rotation and translation, the more integrated technique is faster and easier to use.

An interaction approach to computer animation

Abstract Design of and research on animation interfaces rarely uses methods and theory of human–computer-interaction (HCI). Graphical motion design interfaces are based on dated interaction paradigms, and novel procedures for capturing, processing and mapping motion are preoccupied with aspects of modeling and computation. Yet research in HCI has come far in understanding human cognition and motor skills and how to apply this understanding to interaction design. We propose an HCI perspective on computer animation that relates the state-of-the-art in motion design interfaces to the concepts and terminology of this field. The main contribution is a design space of animation interfaces. This conceptual framework aids relating strengths and weaknesses of established animation methods and techniques. We demonstrate how this interaction-centric approach can be put into practice in the development of a multi-touch animation system.

Proxy-based selection for occluded and dynamic objects

We present a selection technique for 2D and 3D environments based on proxy objects designed to improve selection of occluded and dynamic objects. We explore the design space for proxies, of which we implemented the properties colour similarity and motion similarity and tested them in a user study. Our technique significantly increases selection precision but is slower than the reference selection technique, suggesting a mix of both to optimise speed versus error rate for real world applications.

Left and right hand distinction for multi-touch displays

In the physical world we use both hands in a very distinctive manner. Much research has been dedicated to transfer this principle to the digital realm, including multi-touch interactive surfaces. However, without the possibility to reliably distinguish between hands, interaction design is very limited. We present an approach for enhancing multitouch systems based on diffuse illumination with left and right hand distinction. Using anatomical properties of the human hand we derive a simple empirical model and heuristics that, when fed into a decision tree classifier, enable real-time hand distinction for multi-touch applications.

Advancing large interactive surfaces for use in the real world

Interactive surfaces are only just beginning to break into the market, and they still do not offer the advanced functionality demonstrated with many lab prototypes. The path from a prototype system to a finished product for use in real-world scenarios is a long one, and many obstacles must be overcome. The design of an interactive multitouch table had to address issues like optical recognition, hardware design, and ergonomics. This paper describes in detail the construction of a large, robust multi-touch table called mrT. It will show how to solve major problems of the diffuse illumination technique and other challenges of constructing a large-screen, high-resolution, self-contained interactivemultitouch surface that not only serves as a development system but can be deployed in the real-world. Additionally, to further motivate some of the design decisions, especially why the diffuse illumination technology was chosen, this paper will discuss related on-going research projects on the application side.