Jonathan C. Roberts

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Data analysis often involves the comparison of complex objects. With the ever increasing amounts and complexity of data, the demand for systems to help with these comparisons is also growing. Increasingly, information visualization tools support such comparisons explicitly, beyond simply allowing a viewer to examine each object individually. In this paper,(More)
Fast and accurate collision detection between geometric bodies is essential in application areas like virtual reality, animation, simulation, games and robotics. In this work, we address the collision detection problem in applications where deformable bodies are used, which change their overall shape every time step of the simulation. We propose and(More)
There are many different uses for haptics, such as training medical practitioners, teleoperation, or navigation of virtual environments. This review focuses on haptic methods that display data. The hypothesis is that haptic devices can be used to present information, and consequently, the user gains quantitative, qualitative, or holistic knowledge about the(More)
Exploratory visualization enables the user to test scenarios and investigate possibilities. Through an exploration, the user may change various parameter values of a visualization system that in turn alters the appearance of the visual result. For example, the changesmade may update what information is being displayed, the quantity or resolution of the(More)
Visualization enables ‘seeing the unseen’, and provides new insight into the underlying data. However, users far too easily believe or rely on a single representation of the data; this view may be a favourite method, the simplest to perform, or a method that has always been used! But, a single representation may generate a misinterpretation of the(More)
In this paper, we present a coordination model for exploratory multi-view visualization. We base our work on current research in exploratory visualization and other disciplines. Our model is based on sharing abstract objects such as the visualization parameters of the dataflow model to achieve coordinated exploratory tasks in multiple views. This model(More)
Recently researchers have been interested in non-visual forms of presentation. Sound, touch, smell, as well as vision can be used to depict information. One important medium is sound; it can encode information for the blind or partial sighted, used to display information when it is impossible to use a screen, and the hardware is cheap and widely available.(More)
Different acoustic variables such as pitch, volume, timbre and position can be used to represent quantitative, qualitative and categorical aspects of the information. Such sonifications are particularly useful for those with visual impairments; they are also beneficial in circumstances where visual representations would be impossible to use or to enrich a(More)
This paper presents a BRDF model based on the analysis of the photon collisions with the microfacets of the surface. The new model is not only physically plausible, i.e. symmetric and energy conserving, but provides other important features of real materials, including the off-specular peak and the mirroring limit case. Using theoretical considerations the(More)