Integrating internal behavioural models with external expression

Users will believe in a virtual character more if they can empathise with it and understand what ‘makes it tick’. This will be helped by making the motivations of the character, and other processes that go towards creating its behaviour, clear to the user. This paper proposes that this can be achieved by linking the behavioural or cognitive system of the character to expressive behaviour. This idea is discussed in general and then demonstrated with an implementation that links a simulation of perception to the animation of a character’s eyes

Deceleration without dark matter

In homogeneous isotropic cosmological models the angular size theta of a standard measuring rod changes with redshift z in a manner that depends upon the parameters of the model. It has been argued that as a population ultracompact (milliarcsecond) radio sources measured by very long-baseline interferometry (VLBI) do not evolve with cosmic epoch, and thus comprise a set of standard objects, at least in a statistical sense. Here we examine the angular-size/redshift relation for 256 ultracompact sources with z in the range 0.5 to 3.8 for cosmological models with two degrees of freedom (Omega_0 and Lambda_0). The canonical inflationary cold dark matter model(Omega_0=1, Lambda_0=0) appears to be ruled out by the observed relationship, whereas low-density models with a cosmological constant of either sign are favoured.Comment: Although published (MNRAS 285, 806, 1997, submitted 1996 May 3), this paper has not previously appeared on the arXive. Despite its title, a prominent conclusion is that if the Universe is spatially flat, then the best cosmological parameters are Omega_m=0.2, Omega_Lambda=0.8, with probable range 0.1<Omega_m<0.3. It is the first in a series, the second being JCAP 0411(2004)007, astro-ph/0309390; the third is a recent preprint, astro-ph/060506

Quantitative Analysis of Saliency Models

Previous saliency detection research required the reader to evaluate performance qualitatively, based on renderings of saliency maps on a few shapes. This qualitative approach meant it was unclear which saliency models were better, or how well they compared to human perception. This paper provides a quantitative evaluation framework that addresses this issue. In the first quantitative analysis of 3D computational saliency models, we evaluate four computational saliency models and two baseline models against ground-truth saliency collected in previous work.Comment: 10 page

Decelerating universes older than their Hubble times

Recent observations suggest that Hubble's constant is large, and hence that the Universe appears to be younger than some of its constituents. The traditional escape route, which assumes that the expansion is accelerating, appears to be blocked by observations of Type 1a supernovae, which suggest(ed) that the Universe is decelerating. These observations are reconciled in a model in which the Universe has experienced an inflationary phase in the recent past, driven by an ultra-light inflaton whose Compton wavelength is of the same order as the Hubble radius.Comment: This paper, which predates the famous quintessence paper, has not previously appeared on the e-Print archive. It is essentially a quintessence model without eternal acceleration. Such models are now very topical in the context of string theory. 9 pages, 5 figure

Image Sampling with Quasicrystals

We investigate the use of quasicrystals in image sampling. Quasicrystals produce space-filling, non-periodic point sets that are uniformly discrete and relatively dense, thereby ensuring the sample sites are evenly spread out throughout the sampled image. Their self-similar structure can be attractive for creating sampling patterns endowed with a decorative symmetry. We present a brief general overview of the algebraic theory of cut-and-project quasicrystals based on the geometry of the golden ratio. To assess the practical utility of quasicrystal sampling, we evaluate the visual effects of a variety of non-adaptive image sampling strategies on photorealistic image reconstruction and non-photorealistic image rendering used in multiresolution image representations. For computer visualization of point sets used in image sampling, we introduce a mosaic rendering technique.Comment: For a full resolution version of this paper, along with supplementary materials, please visit at http://www.Eyemaginary.com/Portfolio/Publications.htm

Influence of Dislocations in Thomson's Problem

We investigate Thomson's problem of charges on a sphere as an example of a system with complex interactions. Assuming certain symmetries we can work with a larger number of charges than before. We found that, when the number of charges is large enough, the lowest energy states are not those with the highest symmetry. As predicted previously by Dodgson and Moore, the complex patterns in these states involve dislocation defects which screen the strains of the twelve disclinations required to satisfy Euler's theorem.Comment: 9 pages, 4 figures in gif format. Original PS files can be obtained in http://fermi.fcu.um.es/thomso

What's up prof? Current issues in the visual effects &#38; post-production industry

We interviewed creative professionals at a number of London visual effects and post-production houses. We report on the key issues raised in those interviews: desirable new technologies, infrastructure challenges, personnel and process management