Geometry-based shading for shape depiction Enhancement,

Recent works on Non-Photorealistic Rendering (NPR) show that object shape enhancement requires sophisticated effects such as: surface details detection and stylized shading. To date, some rendering techniques have been proposed to overcome this issue, but most of which are limited to correlate shape enhancement functionalities to surface feature variations. Therefore, this problem still persists especially in NPR. This paper is an attempt to address this problem by presenting a new approach for enhancing shape depiction of 3D objects in NPR. We first introduce a tweakable shape descriptor that offers versatile func- tionalities for describing the salient features of 3D objects. Then to enhance the classical shading models, we propose a new technique called Geometry-based Shading. This tech- nique controls reflected lighting intensities based on local geometry. Our approach works without any constraint on the choice of material or illumination. We demonstrate results obtained with Blinn-Phong shading, Gooch shading, and cartoon shading. These results prove that our approach produces more satisfying results compared with the results of pre- vious shape depiction techniques. Finally, our approach runs on modern graphics hardware in real time, which works efficiently with interactive 3D visualization

Higher level techniques for the artistic rendering of images and video

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Computational haptics : the Sandpaper system for synthesizing texture for a force-feedback display

Thesis (Ph. D.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1995.Includes bibliographical references (p. 155-180).by Margaret Diane Rezvan Minsky.Ph.D

Depth, shading, and stylization in stereoscopic cinematography

Due to the constantly increasing focus of the entertainment industry on stereoscopic imaging, techniques and tools that enable precise control over the depth impression and help to overcome limitations of the current stereoscopic hardware are gaining in importance. In this dissertation, we address selected problems encountered during stereoscopic content production, with a particular focus on stereoscopic cinema. First, we consider abrupt changes of depth, such as those induced by cuts in films. We derive a model predicting the time the visual system needs to adapt to such changes and propose how to employ this model for film cut optimization. Second, we tackle the issue of discrepancies between the two views of a stereoscopic image due to view-dependent shading of glossy materials. The suggested solution eliminates discomfort caused by non-matching specular highlights while preserving the perception of gloss. Last, we deal with the problem of filmgrainmanagement in stereoscopic productions and propose a new method for film grain application that reconciles visual comfort with the idea of medium-scene separation.Aufgrund der ständig steigenden Beachtung der stereoskopische Abbildung durch die Unterhaltungsindustrie, gewinnen Techniken und Werkzeuge an Bedeutung, die eine präzise Steuerung der Tiefenwahrnehmung ermöglichen und Einschränkungen der gegenwärtigen stereoskopischen Geräte überwinden. In dieser Dissertation adressieren wir ausgewählte Probleme, die während der Erzeugung von stereoskopischen Inhalten auftreten, mit besonderem Schwerpunkt auf der stereoskopischen Kinematographie. Zuerst betrachten wir abrupte Tiefenänderungen, wie sie durch Filmschnitte hervergerufen werden. Wir leiten ein Modell her, das die Zeit vorhersagt, die für das menschliche Sehsystem notwendig ist, um sich an solche Änderungen der Tiefe zu adaptieren, und schlagen vor wie dieses Modell für Schnittoptimierung angewendet werden kann. Danach gehen wir das Problem der Unstimmigkeiten zwischen den zwei Ansichten eines stereoskopischen Bildes, infolge der sichtabhängigen Schattierung von glänzenden Materialien, an. Die vorgeschlagene Lösung eliminiert das visuelle Unbehagen, welches von nicht zusammenpassenden Glanzlichtern verursacht wird, indessen bewahrt sie die Glanzwahrnehmung. Zuletzt behandeln wir das Problem des Filmkornsmanagements in stereoskopischen Produktionen und schlagen eine neue Methode für das Hinzufügen vom Filmkorn vor, die die visuelle Behaglichkeit mit der Idee der Medium-Szenen-Trennung in Einklang bringt

The Rock and The Map: two tales of contemporary heritage landscaping in Scotland

As opposed to the ingrained and popularly rehearsed notion that Scotland’s quintessential landscapes are mountainous, remote, rugged and wild, this thesis considers the local landmarks of Dumbarton Rock and the Great Polish Map of Scotland as exemplary of a “New Scottish Landscape”. That is, a new aesthetic, or ‘way of seeing’ the Scottish landscape as one defined by ‘everyday’ local landscapes of affiliation, as much as the ‘special’ and spectacular. Such a belief is given added traction with the demographic fact that the majority of Scotland's population inhabits the densely urbanised Central Belt, in which landscape qualities of 'wildness' and 'remoteness' are generally lacking. Despite this ‘grandeur deficit’, there is increasing recognition that exurban, post-industrial, partially degraded or abandoned landscapes have the capacity to generate intensities of belonging and attachment, reflecting new, distinctive heritage values. Aligned with ‘processual’ conceptual understandings of landscape and heritage as situated, subjective phenomena, ‘the Rock’ and ‘the Map’ are approached in this thesis as instances of “heritage landscaping”, whereby landscape and heritage are figured as conjoined; emerging and unfolding together in practice and experience. Informing a phenomenological methodological design around fieldwork principles of observation, sensation, practice and performance, a range of research materials are gathered to tell the stories of the Rock and the Map. Recounted in two central empirical chapters, the Rock and the Map are explored respectively through the provision of a historical-cultural biography, lending context and time-depth to my own situated experiences through participative intervention. As contrasting but related instances of community-driven heritage landscaping, the Rock and the Map are then considered together to critically engage with recent conceptual developments in landscape and heritage practice towards ‘democratisation’. That is, a loosening of traditionally top-down professional landscape and heritage decision-making, to better account for the often intangible ‘social values’ held by ‘unofficial’ local communities of interest. Drawing upon my situated inquiries of the Rock and the Map, I contend that landscape phenomenology and a ‘performative ethos’ provide a creative and effective means of apprehending and accounting for these alternative narratives, allowing us to uncover and illuminate the latent potential and cultural value held within the New Scottish Landscape

Media Space: an analysis of spatial practices in planar pictorial media.

The thesis analyses the visual space displayed in pictures, film, television and digital interactive media. The argument is developed that depictions are informed by the objectives of the artefact as much as by any simple visual correspondence to the observed world. The simple concept of ‘realism’ is therefore anatomised and a more pragmatic theory proposed which resolves some of the traditional controversies concerning the relation between depiction and vision. This is then applied to the special problems of digital interactive media. An introductory chapter outlines the topic area and the main argument and provides an initial definition of terms. To provide a foundation for the ensuing arguments, a brief account is given of two existing and contrasted approaches to the notion of space: that of perception science which gives priority to acultural aspects, and that of visual culture which emphasises aspects which are culturally contingent. An existing approach to spatial perception (that of JJ Gibson originating in the 1940s and 50s) is applied to spatial depiction in order to explore the differences between seeing and picturing, and also to emphasise the many different cues for spatial perception beyond those commonly considered (such as binocularity and linear perspective). At this stage a simple framework of depiction is introduced which identifies five components or phases: the objectives of the picture, the idea chosen to embody the objectives, the model (essentially, the visual ‘subject matter’), the characteristics of the view and finally the substantive picture or depiction itself. This framework draws attention to the way in which each of the five phases presents an opportunity for decision-making about representation. The framework is used and refined throughout the thesis. Since pictures are considered in some everyday sense to be ‘realistic’ (otherwise, in terms of this thesis, they would not count as depictions), the nature of realism is considered at some length. The apparently unitary concept is broken down into several different types of realism and it is argued that, like the different spatial cues, each lends itself to particular objectives intended for the artefact. From these several types, two approaches to realism are identified, one prioritising the creation of a true illusion (that the picture is in fact a scene) and the other (of which there are innumerably more examples both across cultures and over historical time) one which evokes aspects of vision without aiming to exactly imitate the optical stimulus of the scene. Various reasons for the latter approach, and the variety of spatial practices to which it leads, are discussed. In addition to analysing traditional pictures, computer graphics images are discussed in conjunction with the claims for realism offered by their authors. In the process, informational and affective aspects of picture-making are distinguished, a distinction which it is argued is useful and too seldom made. Discussion of still pictures identifies the evocation of movement (and other aspects of time) as one of the principal motives for departing from attempts at straightforward optical matching. The discussion proceeds to the subject of film where, perhaps surprisingly now that the depiction of movement is possible, the lack of straightforward imitation of the optical is noteworthy again. This is especially true of the relationship between shots rather than within them; the reasons for this are analysed. This reinforces the argument that the spatial form of the fiction film, like that of other kinds of depiction, arises from its objectives, presenting realism once again as a contingent concept. The separation of depiction into two broad classes – one which aims to negate its own mediation, to seem transparent to what it depicts, and one which presents the fact of depiction ostensively to the viewer – is carried through from still pictures, via film, into a discussion of factual television and finally of digital interactive media. The example of factual television is chosen to emphasise how, despite the similarities between the technologies of film and television, spatial practices within some television genres contrast strongly with those of the mainstream fiction film. By considering historic examples, it is shown that many of the spatial practices now familiar in factual television were gradually expunged from the classical film when the latter became centred on the concerns of narrative fiction. By situating the spaces of interactive media in the context of other kinds of pictorial space, questions are addressed concerning the transferability of spatial usages from traditional media to those which are interactive. During the thesis the spatial practices of still-picture-making, film and television are characterised as ‘mature’ and ‘expressive’ (terms which are defined in the text). By contrast the spatial practices of digital interactive media are seen to be immature and inexpressive. It is argued that this is to some degree inevitable given the context in which interactive media artefacts are made and experienced – the lack of a shared ‘language’ or languages in any new media. Some of the difficult spatial problems which digital interactive media need to overcome are identified, especially where, as is currently normal, interaction is based on the relation between a pointer and visible objects within a depiction. The range of existing practice in digital interactive media is classified in a seven-part taxonomy, which again makes use of the objective-idea-model-view-picture framework, and again draws out the difference between self-concealing approaches to depiction and those which offer awareness of depiction as a significant component of the experience. The analysis indicates promising lines of enquiry for the future and emphasises the need for further innovation. Finally the main arguments are summarised and the thesis concludes with a short discussion of the implications for design arising from the key concepts identified – expressivity and maturity, pragmatism and realism

Media Space: an analysis of spatial practices in planar pictorial media.

The thesis analyses the visual space displayed in pictures, film, television and digital interactive media. The argument is developed that depictions are informed by the objectives of the artefact as much as by any simple visual correspondence to the observed world. The simple concept of ‘realism’ is therefore anatomised and a more pragmatic theory proposed which resolves some of the traditional controversies concerning the relation between depiction and vision. This is then applied to the special problems of digital interactive media. An introductory chapter outlines the topic area and the main argument and provides an initial definition of terms. To provide a foundation for the ensuing arguments, a brief account is given of two existing and contrasted approaches to the notion of space: that of perception science which gives priority to acultural aspects, and that of visual culture which emphasises aspects which are culturally contingent. An existing approach to spatial perception (that of JJ Gibson originating in the 1940s and 50s) is applied to spatial depiction in order to explore the differences between seeing and picturing, and also to emphasise the many different cues for spatial perception beyond those commonly considered (such as binocularity and linear perspective). At this stage a simple framework of depiction is introduced which identifies five components or phases: the objectives of the picture, the idea chosen to embody the objectives, the model (essentially, the visual ‘subject matter’), the characteristics of the view and finally the substantive picture or depiction itself. This framework draws attention to the way in which each of the five phases presents an opportunity for decision-making about representation. The framework is used and refined throughout the thesis. Since pictures are considered in some everyday sense to be ‘realistic’ (otherwise, in terms of this thesis, they would not count as depictions), the nature of realism is considered at some length. The apparently unitary concept is broken down into several different types of realism and it is argued that, like the different spatial cues, each lends itself to particular objectives intended for the artefact. From these several types, two approaches to realism are identified, one prioritising the creation of a true illusion (that the picture is in fact a scene) and the other (of which there are innumerably more examples both across cultures and over historical time) one which evokes aspects of vision without aiming to exactly imitate the optical stimulus of the scene. Various reasons for the latter approach, and the variety of spatial practices to which it leads, are discussed. In addition to analysing traditional pictures, computer graphics images are discussed in conjunction with the claims for realism offered by their authors. In the process, informational and affective aspects of picture-making are distinguished, a distinction which it is argued is useful and too seldom made. Discussion of still pictures identifies the evocation of movement (and other aspects of time) as one of the principal motives for departing from attempts at straightforward optical matching. The discussion proceeds to the subject of film where, perhaps surprisingly now that the depiction of movement is possible, the lack of straightforward imitation of the optical is noteworthy again. This is especially true of the relationship between shots rather than within them; the reasons for this are analysed. This reinforces the argument that the spatial form of the fiction film, like that of other kinds of depiction, arises from its objectives, presenting realism once again as a contingent concept. The separation of depiction into two broad classes – one which aims to negate its own mediation, to seem transparent to what it depicts, and one which presents the fact of depiction ostensively to the viewer – is carried through from still pictures, via film, into a discussion of factual television and finally of digital interactive media. The example of factual television is chosen to emphasise how, despite the similarities between the technologies of film and television, spatial practices within some television genres contrast strongly with those of the mainstream fiction film. By considering historic examples, it is shown that many of the spatial practices now familiar in factual television were gradually expunged from the classical film when the latter became centred on the concerns of narrative fiction. By situating the spaces of interactive media in the context of other kinds of pictorial space, questions are addressed concerning the transferability of spatial usages from traditional media to those which are interactive. During the thesis the spatial practices of still-picture-making, film and television are characterised as ‘mature’ and ‘expressive’ (terms which are defined in the text). By contrast the spatial practices of digital interactive media are seen to be immature and inexpressive. It is argued that this is to some degree inevitable given the context in which interactive media artefacts are made and experienced – the lack of a shared ‘language’ or languages in any new media. Some of the difficult spatial problems which digital interactive media need to overcome are identified, especially where, as is currently normal, interaction is based on the relation between a pointer and visible objects within a depiction. The range of existing practice in digital interactive media is classified in a seven-part taxonomy, which again makes use of the objective-idea-model-view-picture framework, and again draws out the difference between self-concealing approaches to depiction and those which offer awareness of depiction as a significant component of the experience. The analysis indicates promising lines of enquiry for the future and emphasises the need for further innovation. Finally the main arguments are summarised and the thesis concludes with a short discussion of the implications for design arising from the key concepts identified – expressivity and maturity, pragmatism and realism