Real-time rendering and simulation of trees and snow

Tree models created by an industry used package are exported and the structure extracted in order to procedurally regenerate the geometric mesh, addressing the limitations of the application's standard output. The structure, once extracted, is used to fully generate a high quality skeleton for the tree, individually representing each section in every branch to give the greatest achievable level of freedom of deformation and animation. Around the generated skeleton, a new geometric mesh is wrapped using a single, continuous surface resulting in the removal of intersection based render artefacts. Surface smoothing and enhanced detail is added to the model dynamically using the GPU enhanced tessellation engine. A real-time snow accumulation system is developed to generate snow cover on a dynamic, animated scene. Occlusion techniques are used to project snow accumulating faces and map exposed areas to applied accumulation maps in the form of dynamic textures. Accumulation maps are xed to applied surfaces, allowing moving objects to maintain accumulated snow cover. Mesh generation is performed dynamically during the rendering pass using surface o�setting and tessellation to enhance required detail

Natural landscape scenic preference: techniques for evaluation and simulation.

The aesthetic beauty of a landscape is a very subjective issue: every person has their own opinions and their own idea of what beauty is. However, all people have a common evolutionary history, and, according to the Biophilia hypothesis, a genetic predisposition to liking certain types of landscapes. It is possible that this common inheritance allows us to attempt to model scenic preference for natural landscapes. The ideal type of model for such predictions is the psychophysical preference model, integrating psychological responses to landscapes with objective measurements of quantitative and qualitative landscape variables. Such models commonly predict two thirds of the variance in the predications of the general public for natural landscapes. In order to create such a model three sets of data were required: landscape photographs (surrogates of the actual landscape), landscape preference data and landscape component variable measurements. The Internet was used to run a questionnaire survey; a novel, yet flexible, environmentally friendly and simple method of data gathering, resulting in one hundred and eighty responses. A geographic information system was used to digitise ninety landscape photographs and measure their landforms (based on elevation) in terms of areas and perimeters, their colours and proxies for their complexity and coherence. Landscape preference models were created by running multiple linear regressions using normalised preference data and the landscape component variables, including mathematical transformations of these variables. The eight models created predicted over sixty percent of variance in the responses and had moderate to high correlations with a second set of landscape preference data. A common base to the models were the variables of complexity, water and mountain landform, in particular the presence or absence of water and mountains was noted as being significant in determining landscape scenic preference. In order to fully establish the utility of these models, they were further tested against: changes in weather and season; the addition of cultural structures; different photographers; alternate film types; different focal lengths; and composition. Results showed that weather and season were not significant in determining landscape preference; cultural structures increased preferences for landscapes; and photographs taken by different people did not produce consistent results from the predictive models. It was also found that film type was not significant and that changes in focal length altered preferences for landscapes

Interactive Generation of Time-Evolving Snow-Covered Landscaped with Avalanches

We introduce a novel method for interactive generation of visually consistent, snow-covered landscapes and provide control of their dynamic evolution over time. Our main contribution is the real-time phenomenological simulation of avalanches and other user-guided events, such as tracks left by Nordic skiing, which can be applied to interactively sculpt the landscape. The terrain is modeled as a height field with additional layers for stable, compacted, unstable, and powdery snow, which behave in combination as a semi-viscous fluid. We incorporate the impact of several phenomena, including sunlight, temperature, prevailing wind direction, and skiing activities. The snow evolution includes snow-melt and snow-drift, which affect stability of the snow mass and the probability of avalanches. A user can shape landscapes and their evolution either with a variety of interactive brushes, or by prescribing events along a winter season time-line. Our optimized GPU-implementation allows interactive updates of snow type and depth across a large (10×10km) terrain, including real-time avalanches, making this suitable for visual assets in computer games. We evaluate our method through perceptual comparison against exiting methods and real snow-depth data

True to nature? Fidelity and transformation in Eugene von Guérard’s antipodean landscape paintings

When the leading mid-nineteenth-century landscape artist in Victoria, Eugene von Guérard, was criticised for failing to illustrate nature sublimely, he replied that his “greatest desire” was to “imitate nature” as far as it was “compatible with the effect of the picture.” Later, he asserted that his aim was “to be true to nature as far as possible” in his art. This empirical, science-informed thesis explores what being “true to nature” meant in Guérard’s practice by examining natural features typically illustrated with fidelity, scrutinising features freely transformed for artistic effect, and assessing whether such transformations compromise his aesthetic ideal. The fieldwork-based study addresses a knowledge gap in Australian art history and environmental history by adopting a multi-disciplinary approach. The findings make a significant contribution to understanding what being “true to nature” meant for Guérard, and to determining whether his landscapes are reliable environmental history records. The investigation uses a mixed-method approach, combining qualitative and quantitative techniques. Early in-depth case studies identified faithfully rendered and freely modified features, which informed the development of an innovative survey instrument used to evaluate the fidelity of over a hundred of Guérard’s Antipodean landscapes. The extent to which natural features are faithful or transformed is subjectively assessed by comparing them with his accurate field drawings and modern site photographs taken from his vantage points. The novel reverse use of digital elevation models enabled many of his vantage points at sites to be precisely determined. Statistical analysis of survey data and further case studies leads to the conclusion that Guérard practised selective fidelity to nature. Although no natural feature was totally immune to being modified for artistic effect, many features are typically reproduced with great fidelity to the natural scenery visible at the site. Features significantly altered to create visually engaging or dramatic landscapes are usually found to be true to the natural history of the location, if not necessarily to the view. Exceptions are largely restricted to the composite landscapes that field research uncovered. Finally, the thesis examines whether Guérard’s fidelity practice resonates with particular purported influences, or parallels the practices of international contemporaries who were also renowned for their wilderness paintings.Doctor of Philosoph

A Framework for Dynamic Terrain with Application in Off-road Ground Vehicle Simulations

The dissertation develops a framework for the visualization of dynamic terrains for use in interactive real-time 3D systems. Terrain visualization techniques may be classified as either static or dynamic. Static terrain solutions simulate rigid surface types exclusively; whereas dynamic solutions can also represent non-rigid surfaces. Systems that employ a static terrain approach lack realism due to their rigid nature. Disregarding the accurate representation of terrain surface interaction is rationalized because of the inherent difficulties associated with providing runtime dynamism. Nonetheless, dynamic terrain systems are a more correct solution because they allow the terrain database to be modified at run-time for the purpose of deforming the surface. Many established techniques in terrain visualization rely on invalid assumptions and weak computational models that hinder the use of dynamic terrain. Moreover, many existing techniques do not exploit the capabilities offered by current computer hardware. In this research, we present a component framework for terrain visualization that is useful in research, entertainment, and simulation systems. In addition, we present a novel method for deforming the terrain that can be used in real-time, interactive systems. The development of a component framework unifies disparate works under a single architecture. The high-level nature of the framework makes it flexible and adaptable for developing a variety of systems, independent of the static or dynamic nature of the solution. Currently, there are only a handful of documented deformation techniques and, in particular, none make explicit use of graphics hardware. The approach developed by this research offloads extra work to the graphics processing unit; in an effort to alleviate the overhead associated with deforming the terrain. Off-road ground vehicle simulation is used as an application domain to demonstrate the practical nature of the framework and the deformation technique. In order to realistically simulate terrain surface interactivity with the vehicle, the solution balances visual fidelity and speed. Accurately depicting terrain surface interactivity in off-road ground vehicle simulations improves visual realism; thereby, increasing the significance and worth of the application. Systems in academia, government, and commercial institutes can make use of the research findings to achieve the real-time display of interactive terrain surfaces

Unlocking Environmental Narratives

Understanding the role of humans in environmental change is one of the most pressing challenges of the 21st century. Environmental narratives – written texts with a focus on the environment – offer rich material capturing relationships between people and surroundings. We take advantage of two key opportunities for their computational analysis: massive growth in the availability of digitised contemporary and historical sources, and parallel advances in the computational analysis of natural language. We open by introducing interdisciplinary research questions related to the environment and amenable to analysis through written sources. The reader is then introduced to potential collections of narratives including newspapers, travel diaries, policy documents, scientific proposals and even fiction. We demonstrate the application of a range of approaches to analysing natural language computationally, introducing key ideas through worked examples, and providing access to the sources analysed and accompanying code. The second part of the book is centred around case studies, each applying computational analysis to some aspect of environmental narrative. Themes include the use of language to describe narratives about glaciers, urban gentrification, diversity and writing about nature and ways in which locations are conceptualised and described in nature writing. We close by reviewing the approaches taken, and presenting an interdisciplinary research agenda for future work. The book is designed to be of interest to newcomers to the field and experienced researchers, and set out in a way that it can be used as an accompanying text for graduate level courses in, for example, geography, environmental history or the digital humanities

Unlocking environmental narratives: towards understanding human environment interactions through computational text analysis

Understanding the role of humans in environmental change is one of the most pressing challenges of the 21st century. Environmental narratives – written texts with a focus on the environment – offer rich material capturing relationships between people and surroundings. We take advantage of two key opportunities for their computational analysis: massive growth in the availability of digitised contemporary and historical sources, and parallel advances in the computational analysis of natural language. We open by introducing interdisciplinary research questions related to the environment and amenable to analysis through written sources. The reader is then introduced to potential collections of narratives including newspapers, travel diaries, policy documents, scientific proposals and even fiction. We demonstrate the application of a range of approaches to analysing natural language computationally, introducing key ideas through worked examples, and providing access to the sources analysed and accompanying code. The second part of the book is centred around case studies, each applying computational analysis to some aspect of environmental narrative. Themes include the use of language to describe narratives about glaciers, urban gentrification, diversity and writing about nature and ways in which locations are conceptualised and described in nature writing. We close by reviewing the approaches taken, and presenting an interdisciplinary research agenda for future work. The book is designed to be of interest to newcomers to the field and experienced researchers, and set out in a way that it can be used as an accompanying text for graduate level courses in, for example, geography, environmental history or the digital humanities

Encoding high dynamic range and wide color gamut imagery

In dieser Dissertation wird ein szenischer Bewegtbilddatensatz mit erweitertem Dynamikumfang (High Dynamic Range, HDR) und großem Farbumfang (Wide Color Gamut, WCG) eingeführt und es werden Modelle zur Kodierung von HDR und WCG Bildern vorgestellt. Die objektive und visuelle Evaluation neuer HDR und WCG Bildverarbeitungsalgorithmen, Kompressionsverfahren und Bildwiedergabegeräte erfordert einen Referenzdatensatz hoher Qualität. Daher wird ein neuer HDR- und WCG-Video-Datensatz mit einem Dynamikumfang von bis zu 18 fotografischen Blenden eingeführt. Er enthält inszenierte und dokumentarische Szenen. Die einzelnen Szenen sind konzipiert um eine Herausforderung für Tone Mapping Operatoren, Gamut Mapping Algorithmen, Kompressionscodecs und HDR und WCG Bildanzeigegeräte darzustellen. Die Szenen sind mit professionellem Licht, Maske und Filmausstattung aufgenommen. Um einen cinematischen Bildeindruck zu erhalten, werden digitale Filmkameras mit ‘Super-35 mm’ Sensorgröße verwendet. Der zusätzliche Informationsgehalt von HDR- und WCG-Videosignalen erfordert im Vergleich zu Signalen mit herkömmlichem Dynamikumfang eine neue und effizientere Signalkodierung. Ein Farbraum für HDR und WCG Video sollte nicht nur effizient quantisieren, sondern wegen der unterschiedlichen Monitoreigenschaften auf der Empfängerseite auch für die Dynamik- und Farbumfangsanpassung geeignet sein. Bisher wurden Methoden für die Quantisierung von HDR Luminanzsignalen vorgeschlagen. Es fehlt jedoch noch ein entsprechendes Modell für Farbdifferenzsignale. Es werden daher zwei neue Farbräume eingeführt, die sich sowohl für die effiziente Kodierung von HDR und WCG Signalen als auch für die Dynamik- und Farbumfangsanpassung eignen. Diese Farbräume werden mit existierenden HDR und WCG Farbsignalkodierungen des aktuellen Stands der Technik verglichen. Die vorgestellten Kodierungsschemata erlauben es, HDR- und WCG-Video mittels drei Farbkanälen mit 12 Bits tonaler Auflösung zu quantisieren, ohne dass Quantisierungsartefakte sichtbar werden. Während die Speicherung und Übertragung von HDR und WCG Video mit 12-Bit Farbtiefe pro Kanal angestrebt wird, unterstützen aktuell verbreitete Dateiformate, Videoschnittstellen und Kompressionscodecs oft nur niedrigere Bittiefen. Um diese existierende Infrastruktur für die HDR Videoübertragung und -speicherung nutzen zu können, wird ein neues bildinhaltsabhängiges Quantisierungsschema eingeführt. Diese Quantisierungsmethode nutzt Bildeigenschaften wie Rauschen und Textur um die benötigte tonale Auflösung für die visuell verlustlose Quantisierung zu schätzen. Die vorgestellte Methode erlaubt es HDR Video mit einer Bittiefe von 10 Bits ohne sichtbare Unterschiede zum Original zu quantisieren und kommt mit weniger Rechenkraft im Vergleich zu aktuellen HDR Bilddifferenzmetriken aus

Unlocking Environmental Narratives

Understanding the role of humans in environmental change is one of the most pressing challenges of the 21st century. Environmental narratives – written texts with a focus on the environment – offer rich material capturing relationships between people and surroundings. We take advantage of two key opportunities for their computational analysis: massive growth in the availability of digitised contemporary and historical sources, and parallel advances in the computational analysis of natural language. We open by introducing interdisciplinary research questions related to the environment and amenable to analysis through written sources. The reader is then introduced to potential collections of narratives including newspapers, travel diaries, policy documents, scientific proposals and even fiction. We demonstrate the application of a range of approaches to analysing natural language computationally, introducing key ideas through worked examples, and providing access to the sources analysed and accompanying code. The second part of the book is centred around case studies, each applying computational analysis to some aspect of environmental narrative. Themes include the use of language to describe narratives about glaciers, urban gentrification, diversity and writing about nature and ways in which locations are conceptualised and described in nature writing. We close by reviewing the approaches taken, and presenting an interdisciplinary research agenda for future work. The book is designed to be of interest to newcomers to the field and experienced researchers, and set out in a way that it can be used as an accompanying text for graduate level courses in, for example, geography, environmental history or the digital humanities

Interpreting nature: shifts in the presentation and display of taxidermy in contemporary museums in Northern England

Taxidermy is an organised craft which synthesises preserved animal skins with man-made materials to recreate a resemblance of living animals. As products of a cultural practice, displayed and interpreted in museums for the public, taxidermied animals are material manifestations of contingent value judgements. Despite the now widely held view in museum studies that the meanings of museum objects are constructed through their interpretation and reception, and therefore can have a multiplicity of meanings, many museums today continue to present and interpret taxidermied animals as objective species representatives. Although scientific themes continue to be privileged by many museums which maintain natural science as a discrete discipline, various social, ethical and political themes relating to the environment and to relationships between people have become more pronounced in recently redeveloped museums. Using Leeds City Museum, the Great North Museum: Hancock, and Museums Sheffield: Weston Park as case studies, this thesis investigates these changes to trace wider cultural shifts in politics, ethics, education and science. By analysing the frameworks within which museums and their staff operate, this investigation is concerned with the relationship between discourse and social practice in the form of museum exhibitions as a means of creating knowledge. It highlights how the public understanding of the natural world is more mutable than some of the enduring traditions of science may suggest, and how the discourses on science, and the objects through which they are articulated, are subject to cultural shifts which put their meanings in flux. This study is both part of, and a response to, an expanding field in museum studies and material culture studies which re-frames taxidermy objects as culturally contingent and therefore reflective of the subject positions of their makers, and the broader contexts of their making. In collating and investigating a diverse collection of archival material, this study recovers some of taxidermy’s histories, and contributes to the historical discourse on the display and interpretation of museum collections