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Item Sketch-Based Posing of 3D Faces for Facial Animation(The Eurographics Association, 2010) Gunnarsson, Orn; Maddock, Steve; John Collomosse and Ian GrimsteadThis paper presents a novel approach to creating 3D facial animation using a sketch-based interface where the animation is generated by interpolating a sequence of sketched key poses. The user does not need any knowledge of the underlying mechanism used to create different expressions or facial poses, and no animation controls or parameters are directly manipulated. Instead, the user sketches the desired shape of a facial feature and the system reconstructs a 3D feature which fits the sketched stroke. This is achieved using a maximum likelihood framework where a statistical model in conjunction with Hidden Markov Models handles sketch detection, and a hierarchical statistical mapping approach reconstructs a posed 3D mesh from a low-dimensional representation.Item A Thin-plate CAD Mesh Model Splitting Approach Based on Fitting Primitives(The Eurographics Association, 2010) Geng, Chun; Suzuki, Hiromasa; Yan, Dong-Ming; Michikawa, Takasi; Sato, Yuichi; Hashima, Masayoshi; Ohta, Eiji; John Collomosse and Ian GrimsteadExtracting structural information from mesh models is crucial for Simulation Driven Design (SDD) in industrial applications. Focusing on thin-plate CAD mesh models (the most commonly used parts in electronic products such as PCs, mobile phones and so on), we present an algorithm based on primitive fitting for segmenting thin-plate CAD mesh models into parts of three different types, two of which are extruding surfaces and the other is a lateral surface. This method can be used for solid model reconstruction in the SDD process. Our approach involves two steps. First, a completely automatic method for accurate primitive fitting on CAD meshes is proposed based on the hierarchical primitive fitting framework. In the second step, a novel procedure is proposed for splitting thin-plate CAD mesh models by detecting parallel extruding surfaces and lateral surfaces. The method presented here has been proved to work smoothly in applications of real product design.Item An Improved Discrete Level of Detail Model Through an Incremental Representation(The Eurographics Association, 2010) Ribelles, Jose; López, Angeles; Belmonte, Oscar; John Collomosse and Ian GrimsteadReal-time applications such as computer and video games, virtual reality and scientific simulation require rendering of complex models for realism. Graphics rendering engines include multiresolution modelling techniques to accelerate the visualization process. The Discrete Level of Detail framework (DLoD) is usually the most popular while the Continuous Level of Detail framework (CLoD) is still not as widely used by software developers. In this paper, we first discuss the benefits and drawbacks of both frameworks. Then, we present a model based on coding a discrete number of levels of detail (LoDs), with more LoDs coded than is usual in DLoD, and with an incremental representation, which is often used in CLoD. This model obtains a performance similar to DLoD by providing optimized LoDs for efficient visualization, while the popping effect is imperceptible. We present specific proposals for each of the three main stages involved in multiresolution processing: geometry simplification, construction of the incremental representation and retrieval of either uniform or view-dependent LoDs.Item Using the Discrete Fourier Transform for Character Motion Blending and Manipulation - a Streamlined Approach(The Eurographics Association, 2010) Molnos, Michael R. L.; Laycock, Stephen D.; Day, Andy M.; John Collomosse and Ian GrimsteadMotion capture data allows natural-looking motion to be bestowed upon simulated characters. Research has sought ways of extending the range of motions it can reproduce. One such method involves blending between captured sequences in the frequency domain. This paper streamlines the approach taken by similar previous work. Higher efficiency is obtained both by shifting computations from runtime to pre-processing and by using a simpler technique, which is also more flexible allowing the method to be used for a greater range of motions. Furthermore, the already-known use of a triangular network defining a continuous blending space is instead presented as an adjustable interface element which is both intuitive and more flexible than applied to earlier work. As before input data may be sparse yet still allows the creation of a continuous spectrum of subtly varying motions, enabling characters to integrate well in their environment. Weighting calculation, blending and Fourier synthesis of realistic-looking motion using five harmonics requires 0.39 ?s per degree of freedom for each frame in the created sequence - a one-off cost incurred only when blending ratios change. This figure can be improved further using the proposed level-of-detail adjustments, which, combined with its small memory footprint, makes the method particularly suitable for the simulation of crowds.Item Integrating Haptic Interaction Into An Existing Virtual Environment Toolkit(The Eurographics Association, 2010) Scopes, Peter; Smith, Shamus P.; John Collomosse and Ian GrimsteadThere is increasing demand for haptic, or touch-based, interaction in virtual environments. Although many haptic devices come with APIs to enable the development of haptic-based applications, many do not provide the same level of graphical support available in virtual environment or game technology toolkits. This paper will discuss the integration of haptic interaction into an existing virtual environment toolkit. By creating a flexible middleware component, haptic interaction and force feedback for a haptic device can augment sensory experiences in existing virtual environments. A user study was conducted to evaluate the integration of haptics and realistic physics in an example virtual environment.Item Using Processing to Develop iCove: a Tool for Interactive Coastal Oceanographic Visualization(The Eurographics Association, 2010) George, Richard L. S. F.; Roberts, Jonathan C.; Davies, Alan G.; John Collomosse and Ian GrimsteadWe have been developing iCove: the interactive coastal oceanographic visualization environment. The challenge for the ocean scientists is that their models are complex and the datasets that are generated are huge. Furthermore, the oceanographers wish to interactively investigate and quantitatively compare different runs of these models. We propose a novel visual analytics tool to permit detailed exploration through interactive data querying to enable their analysis. This paper presents our experience of building iCove in Processing especially in comparison with our previous oceanographic tool building in VTK.Item Anatomically Plausible Surface Alignment and Reconstruction(The Eurographics Association, 2010) Paulsen, Rasmus R.; Larsen, Rasmus; John Collomosse and Ian GrimsteadWith the increasing clinical use of 3D surface scanners, there is a need for accurate and reliable algorithms that can produce anatomically plausible surfaces. In this paper, a combined method for surface alignment and reconstruction is proposed. It is based on an implicit surface representation combined with a Markov Random Field regularisation method. Conceptually, the method maintains an implicit ideal description of the sought surface. This implicit surface is iteratively updated by realigning the input point sets and Markov Random Field regularisation. The regularisation is based on a prior energy that has earlier proved to be particularly well suited for human surface scans. The method has been tested on full cranial scans of ten test subjects and on several scans of the outer human ear.Item Perception of Clones in Forest Rendering(The Eurographics Association, 2010) Purvis, Alan; Sundstedt, Veronica; John Collomosse and Ian GrimsteadThe application of instanced clones represents a powerful technique for reducing the time and space requirements of the storage and visualization of large populations of similar objects. This paper presents the results of several perceptual experiments into the application of cloning to plant populations, within the context of a project to explore the use of resource-acquisition based techniques to model plant distributions. The perceptive effects of clone rotation on human subjects will be explored, with the goal of stratifying clone rotations and minimizing their detection. The perceptual effects of clone number, plant species heterogeneity and appearance will also be explored.Item Animating Horse Gaits and Transitions(The Eurographics Association, 2010) Murphy, James E.; Carr, Hamish; O'Neill, Michael; John Collomosse and Ian GrimsteadAnimations of horses are commonly used for entertainment purposes. A realistic animated model must move with a gait appropriate to its velocity. We present a kinematic animation system in which a horse model moves using gaits and transitions based on predictions from Dynamic Similarity theory. A Genetic Programming technique is used to evolve gait motion with dynamically adjustable limb extent. The system is controlled in real-time using a MIDI controller system based around the model's Froude number. We were successful in producing high quality animations of the horse's natural gaits and transitions.Item Efficient Image Blur in Web-Based Applications(The Eurographics Association, 2010) Kraus, Martin; John Collomosse and Ian GrimsteadScripting languages require the use of high-level library functions to implement efficient image processing; thus, real-time image blur in web-based applications is a challenging task unless specific library functions are available for this purpose. We present a pyramid blur algorithm, which can be implemented using a subimage copy function, and evaluate its performance with various web browsers in comparison to an infinite impulse response filter. While this pyramid algorithm was first proposed for GPU-based image processing, its applicability to web-based applications indicates that some GPU techniques are of more general interest than previously assumed.