This work will give a wide survey for various techniques that are present in the field of character computer animation, which concentrates particularly on those techniques and problems involved in the production of realistic character synthesis and motion. A preliminary user study (including Questionnaire, online publishing such as flicker.com, interview, multiple choice questions, publishing on Android mobile phone, and questionnaire analysis, validation, statistical evaluation, design steps and Character Animation Observation) was conducted to explore design questions, identify users' needs, and obtain a "true story" of quality character animation and the effect of using animation as useful tools in Education. The first set of questionnaires were designed to accommodate the evaluation of animation from candidates from different walks of life, ranging from animators, gamers, teacher assistances (TA), students, teaches, professionals and researchers using and evaluating pre-prepared animated character videos scenarios, and the study outcomes has reviewed the recent advances techniques of character animation, motion editing that enable the control of complex animations by interactively blending, improving and tuning artificial or captured motions. The goal of this work was to augment the students learning intuition by providing ways to make education and learning more interesting, useful and fun objectively, in order to improve students’ respond and understanding to any subject area through the use of animation also by producing the required high quality motion, reaction, interaction and story board to viewers of the motion. We present a variety of different evaluation to the motion quality by measuring user sensitivity, observations to any noticeable artefact, usability, usefulness etc. to derive clear useful guidelines from the results, and discuss several interesting systematic trends we have uncovered in the experimental data. We also present an efficient technique for evaluating the capability of animation influence on education to fulfil the requirements of a given scenario, along with the advantages and the effect on those deficiencies of some methods commonly used to improve animation quality to serve the learning process. Finally, we propose a wide range of extensions and statistical calculation enabled by these evaluation tools, such as Wilcoxon, F-test, T-test, Wondershare Quiz creator (WQC), Chi square and many others explained with full details.

published_or_final_version / Computer Science and Information Systems / Master / Master of Philosophy

published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy

The desktop publishing revolution of the 1980s is currently repeating itself in 3D, referred to as desktop manufacturing. Online services such as Shapeways have become available, making personalized manufacturing on cutting edge additive manufacturing (AM) technologies accessible to a broad audience. Affordable desktop printers will soon take over, enabling people to fabricate / Engineering and Applied Sciences

Šiame darbe pristatysime du alternatyvius, vienus iš pačių populiariausių, realaus laiko šešėlių generavimo metodus. Tai šešėlių planų (angl. shadow maps) ir šešėlių tūrių (angl. shadow volumes) metodai. Kadangi šie metodai turi įvairių skirtingų privalumų ir trūkumų, yra nuolat tobulinami, kartais kuriami ir iš jų ir hibridiniai algoritmai, kurie perimtų kuo daugiau šių dviejų technikų gerųjų savybių. Todėl šiame darbe pamėginsime nustatyti ir įvertinti, kuriais atvejais yra vienas geresnis už kitą. / In this work we introduce to two alternative, most popular real time shadow rendering techniques. This is shadow map (or mapping) and shadow volumes techniques. Because those two methods have diferent advantages and weaknesses, there are always in development, and sometimes hybrid algorithms are created, which would absorb more good features from them. So in this work we tried to determine and rate in which cases one is better than another.

Live video communications over bandwidth constrained ad-hoc radio networks necessitates high compression rates. To this end, a model based video communication system that incorporates flexible and accurate 3D modelling and reconstruction is proposed in part. Model-based video coding (MBVC) is known to provide the highest compression rates, but usually compromises photorealism and object detail. High compression ratios are achieved at the encoder by extracting and transmit- ting only the parameters which describe changes to object orientation and motion within the scene. The decoder uses the received parameters to animate reconstructed objects within the synthesised scene. This is scene understanding rather than video compression. 3D reconstruction of objects and scenes present at the encoder is the focus of this research. 3D Reconstruction is accomplished by utilizing the Patch-based Multi-view Stereo (PMVS) frame- work of Yasutaka Furukawa and Jean Ponce. Surface geometry is initially represented as a sparse set of orientated rectangular patches obtained from matching feature correspondences in the input images. To increase reconstruction density these patches are iteratively expanded, and filtered using visibility constraints to remove outliers. Depending on the availability of segmentation in- formation, there are two methods for initialising a mesh model from the reconstructed patches. The first method initialises the mesh from the object's visual hull. The second technique initialises the mesh directly from the reconstructed patches. The resulting mesh is then refined by enforcing patch reconstruction consistency and regularization constraints for each vertex on the mesh. To improve robustness to outliers, two enhancements to the above framework are proposed. The first uses photometric consistency during feature matching to increase the probability of selecting the correct matching point first. The second approach estimates the orientation of the patch such that its photometric discrepancy score for each of its visible images is minimised prior to optimisation. The overall reconstruction algorithm is shown to be flexible and robust in that it can reconstruct 3D models for objects and scenes. It is able to automatically detect and discard outliers and may be initialised by simple visual hulls. The demonstrated ability to account for surface orientation of the patches during photometric consistency computations is a key performance criterion. Final results show that the algorithm is capable of accurately reconstructing objects containing fine surface details, deep concavities and regions without salient textures. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.

Image based lighting, (IBL), is a computer graphics technique for creating photorealistic renderings of synthetic objects such that they can be placed into real world scenes. IBL has been widely recognized and is today used in commercial production pipelines. However, the current techniques only use illumination captured at a single point in space. This means that traditional IBL cannot capture or recreate effects such as cast shadows, shafts of light or other important spatial variations in the illumination. Such lighting effects are, in many cases, artistically created or are there to emphasize certain features, and are therefore a very important part of the visual appearance of a scene. This thesis and the included papers present methods that extend IBL to allow for capture and rendering with spatially varying illumination. This is accomplished by measuring the light field incident onto a region in space, called an Incident Light Field, (ILF), and using it as illumination in renderings. This requires the illumination to be captured at a large number of points in space instead of just one. The complexity of the capture methods and rendering algorithms are then significantly increased. The technique for measuring spatially varying illumination in real scenes is based on capture of High Dynamic Range, (HDR), image sequences. For efficient measurement, the image capture is performed at video frame rates. The captured illumination information in the image sequences is processed such that it can be used in computer graphics rendering. By extracting high intensity regions from the captured data and representing them separately, this thesis also describes a technique for increasing rendering efficiency and methods for editing the captured illumination, for example artificially moving or turning on and of individual light sources.

Visualization of trivariate functions and vector fields with three components in scientific computation is still a hard problem in compute graphic area. People build their own visualization packages for their special purposes. And there exist some general-purpose packages (MatLab, Vis5D), but they all require extensive user experience on setting all the parameters in order to generate images. We present a simple package to produce simplified but productive images of 3-D vector fields. We used this method to render the magnetic field and current as solutions of the Ginzburg-Landau equations on a 3-D domain.

This thesis discusses cloth simulations for visual effects production, and thereplication of real life garments in that context. The purpose is to get anunderstanding for the practical process of recreating actual cloth garments, andthrough this work explore the behaviour of cloth materials and the importance of theirspecific traits in a simulation context. This is achieved through recreating threespecific cloth garments in a computer simulation package, cross-referencingobserved cloth properties as guidance. The resulting videos are then compared sideby side with filmed reference by the author and through a survey, along with similarlooking simulations to evaluate the quality of the simulations. The results show that itis possible to digitally recreate real world garments, with accuracy being mostlydepending on resolution, model accuracy and apparent thickness. The report alsohighlights a need for further research into tangible cloth recreation.

Un graphe est un objet mathématique modélisant des relations sur un ensemble d'éléments. Il est utilisé dans de nombreux domaines à des fins de modélisation. La taille et la complexité des graphes manipulés de nos jours entraînentdes besoins de visualisation afin de mieux les analyser. Dans cette thèse, nous présentons différents travaux en visualisation interactive de graphes qui s'attachent à exploiter les architectures de calcul parallèle (CPU et GPU) disponibles sur les stations de travail contemporaines. Un premier ensemble de travaux s'intéresse à des problématiques de dessin de graphes. Dessiner un graphe consiste à le plonger visuellement dans un plan ou un espace. La première contribution dans cette thématique est un algorithmede regroupement d'arêtes en faisceaux appelé Winding Roads.Cet algorithme intuitif, facilement implémentable et parallélisable permet de réduireconsidérablement les problèmes d'occlusion dans un dessin de graphedus aux nombreux croisements d'arêtes.La seconde contribution est une méthode permettant dedessiner un réseau métabolique complet. Ce type deréseau modélise l'ensemble des réactions biochimiquesse produisant dans les cellules d'un organise vivant.L'avantage de la méthode est de prendre en compte la décompositiondu réseau en sous-ensembles fonctionnels ainsi que de respecterles conventions de dessin biologique.Un second ensemble de travaux porte sur des techniques d'infographiepour la visualisation interactive de graphes. La première contribution dans cette thématique est une technique de rendude courbes paramétriques exploitant pleinement le processeur graphique. La seconde contribution est une méthodede rendu nommée Edge splatting permettant de visualiserla densité des faisceaux d'arêtes dans un dessin de grapheavec regroupement d'arêtes. La dernière contribution portesur des techniques permettant de mettre en évidence des sous-graphesd'intérêt dans le contexte global d'une visualisation de graphes. / A graph is a mathematical object used to model relations over a set of elements.It is used in numerous fields for modeling purposes. The size and complexityof graphs manipulated today call a need for visualization to better analyze them.In that thesis, we introducedifferent works in interactive graph visualisation which aim at exploiting parallel computing architectures (CPU and GPU) available on contemporary workstations.A first set of works focuses on graph drawing problems.Drawing a graph consists of embedding him in a plane or a space.The first contribution in that theme is an edge bundling algorithmnamed Winding Roads. That intuitive, easyly implementable and parallelizable algorithmallows to considerably reduce clutter due to numerous edge crossings in a graph drawing.The second contribution is a method to draw a complete metabolicnetwork. That kind of network models the whole set of biochemical reactionsoccurring within cells of a living organism. The advantage of the methodis to take into account the decomposition of the network into functionnal subsetsbut also to respect biological drawing conventions.A second set of works focuses on computer graphics techniquesfor interactive graph visualisation. The first contributionin that theme is a technique for rendering parametric curvesthat fully exploits the graphical processor unit. The second contributionis a rendering technique named Edge splatting that allowsto visualize the bundles densities in an edge bundled layout. Thelast contribution introduces some techniques for emphasizingsub-graphs of interest in the global context of a graph visualization.