Steven Collins

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Skinning of skeletally deformable models is extensively used for real-time animation of characters, creatures and similar objects. The standard solution, linear blend skinning, has some serious drawbacks that require artist intervention. Therefore, a number of alternatives have been proposed in recent years. All of them successfully combat some of the(More)
When simulating large crowds, it is inevitable that the models and motions of many virtual characters will be cloned. However, the perceptual impact of this trade-off has never been studied. In this paper, we consider the ways in which an impression of variety can be created and the perceptual consequences of certain design choices. In a series of(More)
We present a new approach to deformable image registration suitable for articulated images such as hand-drawn cartoon characters and human postures. For such type of data state-of-the-art techniques typically yield undesirable results. We propose a novel geometrically motivated iterative scheme where point movements are decoupled from shape consistency. By(More)
We present an extension to existing techniques to provide for more accurate resolution of specular to diffuse transfer within a global illumination framework. In particular this new model is adaptive with a view to capturing high frequency phenomena such as caustic curves in sharp detail and yet allowing for low frequency detail without compromising noise(More)
In this paper we present LazyBrush, a novel interactive tool for painting hand-made cartoon drawings and animations. Its key advantage is simplicity and flexibility. As opposed to previous custom tailored approaches [SBv05, QWH06] LazyBrush does not rely on style specific features such as homogenous regions or pattern continuity yet still offers comparable(More)
Quaternions have been a popular tool in 3D computer graphics for more than 20 years. However, classical quaternions are restricted to the representation of rotations, whereas in graphical applications we typically work with rotation composed with translation (i.e., a rigid transformation). Dual quaternions represent rigid transformations in the same way as(More)
The animation and rendering of crowds of realistically clothed characters presents a difficult challenge in computer graphics, which is further exacerbated when real-time frame rates are required. To date, due to real-time constraints, standard skinning methods have been used to animate the clothes of individuals in real-time crowds, which does not create(More)
Recent developments in crowd simulation have allowed thousands of characters to be rendered in real-time. Usually this is achieved through the use of Level of Detail (LOD) models for the individuals in the crowd. Perceptual studies have shown that image-based representations, i.e., impostors, can be used as imperceptible background substitutes for(More)
Perceptually-Adaptive Collision Detection for Real-time Computer Animation Carol O'Sullivan Supervisor: Dr. Steven Collins The aim of interactive animation systems is to create an exciting and real experience for viewers, to give them a feeling of immersion, of “being there". The tendency in the past has been to attempt to achieve this by matching as(More)