Volumetric cloud generation using a Chinese brush calligraphy style

Includes bibliographical references.Clouds are an important feature of any real or simulated environment in which the sky is visible. Their amorphous, ever-changing and illuminated features make the sky vivid and beautiful. However, these features increase both the complexity of real time rendering and modelling. It is difficult to design and build volumetric clouds in an easy and intuitive way, particularly if the interface is intended for artists rather than programmers. We propose a novel modelling system motivated by an ancient painting style, Chinese Landscape Painting, to address this problem. With the use of only one brush and one colour, an artist can paint a vivid and detailed landscape efficiently. In this research, we develop three emulations of a Chinese brush: a skeleton-based brush, a 2D texture footprint and a dynamic 3D footprint, all driven by the motion and pressure of a stylus pen. We propose a hybrid mapping to generate both the body and surface of volumetric clouds from the brush footprints. Our interface integrates these components along with 3D canvas control and GPU-based volumetric rendering into an interactive cloud modelling system. Our cloud modelling system is able to create various types of clouds occurring in nature. User tests indicate that our brush calligraphy approach is preferred to conventional volumetric cloud modelling and that it produces convincing 3D cloud formations in an intuitive and interactive fashion. While traditional modelling systems focus on surface generation of 3D objects, our brush calligraphy technique constructs the interior structure. This forms the basis of a new modelling style for objects with amorphous shape

The structure, perception and generation of musical patterns

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2004.Includes bibliographical references (p. 149-151).Structure distinguishes music from noise. When formulating that structure, musical artists rely on both mental representations and sensory perceptions to organize pitch, rhythm, harmony, timbre and dynamics into musical patterns. The generative process may be compared to playing a game, with goals, constraints, rules and strategies. In this study, games serve as a model for the interrelated mechanisms of music creation, and provide a format for an experimental technique that constrains creators as they generate simple rhythmic patterns. Correlations between subjects' responses and across experiments with varied constraints provide insight into how structure is defined in situ and how constraints impact creators' perceptions and decisions. Through the music composition games we investigate the nature of generative strategizing, refine a method for observing the generative process, and model the interconnecting components of a generative decision. The patterns produced in these games and the findings derived from observing how the games are played elucidate the roles of metric inference, preference and the perception of similarity in the generative process, and lead us to a representation of generative decision tied to a creator's perception of structure.M. Nyssim Lefford.Ph.D

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

Pan-genomics and the structural diversity of plant genomes

A central task of genetics research is to uncover genotypes linked to important phenotypes. However, many genomic loci are incompletely or inaccurately represented in genetics studies, thus obscuring their function and evolution. New technology can accurately and continuously sequence large segments of genomic DNA at affordable cost and unprecedented scale, raising the possibility of complete and accurate representations of genomes across the tree of life. However, new computational methods are required to automatically finish, validate, and curate the forthcoming wave of genome assemblies enabled by these technologies. Researchers must also devise analytical approaches to comparing previously unresolved and usually repetitive genomic loci within and between species. Here, we introduce RaGOO and RagTag, new methods that leverage genome maps to automatically scaffold and improve draft genome assemblies into chromosome-scale representations. By applying these new methods to a bread wheat genome, we show how the established reference falsely collapsed functional paralogs genome-wide. In Arabidopsis thaliana, we present a new reference assembly that completely resolves all five centromeres for the first time, revealing centromere architecture, genetics, epigenetics, and evolution. Finally, we present a catalog of natural structural variants (SVs) across 100 diverse tomato accessions revealing exceptional genetic diversity via artificial introgression as well as broad and specific examples of how SVs influence molecular, domestication, and improvement phenotypes. This work underscores the potential to accelerate genetics research with complete and diverse genotype data and apply these findings to plant breeding and engineering

Visually tracked flashlights as interaction devices

This thesis examines the feasibility, development and deployment of visually tracked flashlights as interaction devices. Flashlights are cheap, robust and fun. Most people from adults to children of an early age are familiar with flashlights and can use them to search for, select and illuminate objects and features of interest. Flashlights are available in many shapes, sizes, weights and mountings. Flashlights are particularly appropriate to situations where visitors explore dark places such as the caves, tunnels, cellars and dungeons that can be found in museums, theme parks and other visitor attractions. Techniques are developed by which the location and identity of flashlight projections are recovered from the image sequence supplied by a fixed camera monitoring a target surface. The information recovered is used to trigger audiovisual events in response to users' actions. Early trials with three prototype systems, each built using existing techniques in computer vision, show flashlight interfaces to be feasible both technically and from a usability point of view. Novel methods are developed which allow extraction of descriptions of flashlight projections that are independent of the reflectance of the underlying physical surface. Those descriptions are used to locate and recognise individual flashlights and support a multi-user interface technology. The methods developed form the basis of Enlighten, a software product marketed by the University of Nottingham spinoff company Visible Interactions Ltd. Enlighten is currently is daily use at four sites across the UK. Two patents have been filed (UK Patent Publication Number GB2411957 and US Patent Application Number 10/540,498). The UK patent has been granted, and the US application is under review