Document Collection Visualization and Clustering Using An Atom Metaphor for Display and Interaction

Visual Data Mining have proven to be of high value in exploratory data analysis and data mining because it provides an intuitive feedback on data analysis and support decision-making activities. Several visualization techniques have been developed for cluster discovery such as Grand Tour, HD-Eye, Star Coordinates, etc. They are very useful tool which are visualized in 2D or 3D; however, they have not simple for users who are not trained. This thesis proposes a new approach to build a 3D clustering visualization system for document clustering by using k-mean algorithm. A cluster will be represented by a neutron (centroid) and electrons (documents) which will keep a distance with neutron by force. Our approach employs quantified domain knowledge and explorative observation as prediction to map high dimensional data onto 3D space for revealing the relationship among documents. User can perform an intuitive visual assessment of the consistency of the cluster structure

3D mesh animation system targeted for multi-touch environments

Ankara : The Department of Computer Engineering and the Institute of Engineering and Science of Bilkent University, 2009.Thesis (Master's) -- Bilkent University, 2009.Includes bibliographical references leaves 74-78.Fast developments in computer technology have given rise to different application areas such as multimedia, computer games, and Virtual Reality. All these application areas are based on animation of 3D models of real world objects. For this purpose, many tools have been developed to enable computer modeling and animation. Yet, most of these tools require a certain amount of experience about geometric modeling and animation principles, which creates a handicap for inexperienced users. This thesis introduces a solution to this problem by presenting a mesh animation system targeted specially for novice users. The main approach is based on one of the fundamental model representation concepts, Laplacian framework, which is successfully used in model editing applications. The solution presented perceives a model as a combination of smaller salient parts and uses the Laplacian framework to allow these parts to be manipulated simultaneously to produce a sense of movement. The interaction techniques developed enable users to carry manipulation and global transformation actions at the same time to create more pleasing results. Furthermore, the approach utilizes the multi-touch screen technology and direct manipulation principles to increase the usability of the system. The methods described are experimented by creating simple animations with several 3D models; which demonstrates the advantages of the proposed solution.Ceylan, DuyguM.S

Generalized Trackball and 3D Touch Interaction

This thesis faces the problem of 3D interaction by means of touch and mouse input. We propose a multitouch enabled adaptation of the classical mouse based trackball interaction scheme. In addition we introduce a new interaction metaphor based on visiting the space around a virtual object remaining at a given distance. This approach allows an intuitive navigation of topologically complex shapes enabling unexperienced users to visit hard to be reached parts

Automatic Speed Control For Navigation in 3D Virtual Environment

As technology progresses, the scale and complexity of 3D virtual environments can also increase proportionally. This leads to multiscale virtual environments, which are environments that contain groups of objects with extremely unequal levels of scale. Ideally the user should be able to navigate such environments efficiently and robustly. Yet, most previous methods to automatically control the speed of navigation do not generalize well to environments with widely varying scales. I present an improved method to automatically control the navigation speed of the user in 3D virtual environments. The main benefit of my approach is that automatically adapts the navigation speed in multi-scale environments in a manner that enables efficient navigation with maximum freedom, while still avoiding collisions. The results of a usability tests show a significant reduction in the completion time for a multi-scale navigation task

Mathematical models for perceived roughness of three-dimensional surface textures

This thesis reports and discusses results from a new methodology for investigating the visually perceived properties of surfaces; by doing so, it also discovers a measurement or estimator for perceived roughness of 1/Fβ noise surfaces. Advanced computer graphics were used to model natural looking surfaces (1/Fβ noise surfaces). These were generated and animated in real-time to enable observers to manipulate dynamically the parameters of the rendered surfaces. A method of adjustment was then employed to investigate the effects of changing the parameters on perceived roughness. From psychophysical experiments, it was found that the two most important parameters related to perceived roughness were the magnitude roll-off factor (β) and RMS height (σ) for this kind of surfaces. From the results of various extra experiments, an estimation method for perceived roughness was developed; this was inspired by common frequency-channel models. The final optimized model or estimator for perceived roughness in 1/Fβ noise surfaces found was based on a FRF model. In this estimator, the first filter has a shape similar to a gaussian function and the RF part is a simple variance estimator. By comparing the results of the estimator with the observed data, it is possible to conclude that the estimator accurately represents perceived roughness for 1/Fβ noise surfaces

Large-Scale Structure in the Universe

Cosmologists are currently researching the theory of large-scale structures, which are in essence groups of neighbouring galaxies. Recent “galaxy-hunts” have resulted in data for hundreds of thousands of galaxies being made publicly available, and it has become infeasible to isolate large-scale structures by hand from this data. Furthermore, it is difficult for cosmologists to visualise such structures by simply observing the galaxies that comprise the structure; they need a graphically rendered system in which they can change their viewpoint and observe the structure from any position desired. We present a system that identifies large-scale structures from datasets of galaxy information, and then displays the data using OpenGL in such a way that the user can “fly” through space in realtime, observing not only a single structure but the entire dataset and how structures are positioned relative to each other

Generating Calligraphic Trajectories with Model Predictive Control

We describe a methodology for the interactive definition of curves and motion paths using a stochastic formulation of optimal control. We demonstrate how the same optimization framework can be used in different ways to generate curves and traces that are geometrically and dynamically similar to the ones that can be seen in art forms such as calligraphy or graffiti art. The method provides a probabilistic description of trajectories that can be edited similarly to the control polygon typically used in the popular spline based methods. Furthermore, it also encapsulates movement kinematics, deformations and variability. The user is then provided with a simple interactive interface that can generate multiple movements and traces at once, by visually defining a distribution of trajectories rather than a single one. The input to our method is a sparse sequence of targets defined as multivariate Gaussians. The output is a dynamical system generating curves that are natural looking and reflect the kinematics of a movement, similar to that produced by human drawing or writing

AutoGraff: towards a computational understanding of graffiti writing and related art forms.

The aim of this thesis is to develop a system that generates letters and pictures with a style that is immediately recognizable as graffiti art or calligraphy. The proposed system can be used similarly to, and in tight integration with, conventional computer-aided geometric design tools and can be used to generate synthetic graffiti content for urban environments in games and in movies, and to guide robotic or fabrication systems that can materialise the output of the system with physical drawing media. The thesis is divided into two main parts. The first part describes a set of stroke primitives, building blocks that can be combined to generate different designs that resemble graffiti or calligraphy. These primitives mimic the process typically used to design graffiti letters and exploit well known principles of motor control to model the way in which an artist moves when incrementally tracing stylised letter forms. The second part demonstrates how these stroke primitives can be automatically recovered from input geometry defined in vector form, such as the digitised traces of writing made by a user, or the glyph outlines in a font. This procedure converts the input geometry into a seed that can be transformed into a variety of calligraphic and graffiti stylisations, which depend on parametric variations of the strokes