Ian Stephenson

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A development environment for RenderMan shaders has been implemented, allowing the SL programmer to observe the bahaviour of variables in both time and space. By allowing both novices and experts to visualise the execution of their code, the creation of shaders is much simplified without restricting the flexability of the SL language.
Soft re-use of brownfields describes intended temporary or final re-uses of brownfield sites which are not based on built constructions or infrastructure ('hard' re-use). Examples of soft re-uses include the creation of public green space. These are essentially uses where the soil is not sealed. Often the case for soft re-use of brownfields has not been(More)
Many publications on rendering at some point make reference to a theoretical or ideal pinhole camera model, the implication being that an infinitely small hole will produce a perfectly sharp image. However this is not the case. The assumptions of ray, and particle based models of light transport do not accurately represent the results obtained from small(More)
It is commonly acknowledged that the the instantaneous shutter model used in primitive rendering systems produces images which are unrealistic, and animate poorly. However the introduction of motion blur as implemented in most modern renderers uses a shutter model which is equally implausible. One of the few articles to examine this effect is [Glassner(More)
As graphics hardware increases in power, driven by low cost consumer level products, there is an inevitable blurring between real time, and high end production techniques. Games developers are increasingly able to use techniques which where previously too slow, while producers of animation cannot ignore the powerful custom hardware available for rendering.(More)
Grain is perhaps the most obvious artifact introduced by film, but most existing treatments of film grain in both photography and computer graphics consider grain as a layer of noise added onto a perfect image, amplitude of the noise being modulated by the image density. However real grain forms the visible image, with individual grains either being(More)