Discussed is the design, implementation and use of a graPHIGS (IBM PHIGS) based sub-system that provides for shading of graphical models using the Phong shading technique. The ISO standard for 3D graphics, PHIGS, provides for wireframe display and manipulation of graphics data. PHIGS + implementations, while providing this capability, will not be widely available for some time. This capability will provide a generally useful extension to PHIGS for use by PHIGS based applications. The software provides the applications programmer with a graPHIGS based instruction set which acts as a superset to the current graPHIGS calls. Using the provided functions the user can quickly do hidden surface elimination and Phong rendering of 3-D models in 3-D views. The program contains approximately 15,000 lines of C code and uses graPHIGS inquiries and calls for information retrieval and data structure maintenance. / Master of Science

Doctor of Philosophy / Department of Educational Leadership / Kakali Bhattacharya / Royce Ann Collins / How can an adult make meaning from and develop through experiences of mental illness, spiritual awareness, and death? The purpose of this autoethnographic bildungsroman is to explore how a male in the general population describes how life events have influenced his identity development over a period of 23 years, spanning three decades. The researcher-participant asks two primary questions: 1) How does the individual describe his adult development in terms of life events or “individual and cultural episodes” (Smith & Taylor, 2010, p. 52) related to mental illness, spiritual awareness, and death over time? and 2) How does the individual describe his possible selves in constructing a new sense of identity? Addressing these questions contributes to the literature of adult and continuing education by providing a glimpse into stories of lived experiences over time in the light of adult development.

Thesis advisor: Yvette D. Kuiper / Crystallographic Preferred Orientations (CPO) are common in deformed rocks, and usually result from crystal plastic deformation by dislocation creep. Whether deformation mechanisms that occur at lower differential stress and lower temperature than dislocation creep, such as Dissolution-Precipitation Creep (DPC), may result in the development of a CPO is less certain. DPC, a process also known as pressure-solution creep or dissolution creep, has caused substantial removal and reprecipitation of quartz within the Purgatory Conglomerate of Rhode Island. The conglomerate is exposed within the southeastern region of the Pennsylvanian Narragansett basin and experienced folding during the Alleghanian orogeny. Strain within the southeastern portion of the Narragansett basin increases from west to east and is associated with a metamorphic gradient from very low grade greenschist facies in the west to the lower biotite zone in the east. Within the Pugatory Conglomerate DPC has led to the dissolution of quartz along cobble surfaces perpendicular to the shortening direction, and to be precipitated as overgrowths at the ends of the cobbles (strain shadows), parallel to the maximum extension direction. This offers a unique opportunity to study the effects of dissolution and precipitation separately, because the quartz grains within the cobbles experienced dissolution only, while precipitation occurred in the strain shadows. Cathodoluminescence (CL) analysis was conducted on regions within the strain shadow in order to determine what amount of the quartz was formed authigenically. The results suggest that quartz-rich areas of the strain shadow were comprised primarily of authigenic quartz and formed channels or wedges. Electron Backscatter Diffraction (EBSD) analysis was used to test whether quartz dissolution processes within the cobbles and/or quartz precipitation within the strain shadows resulted in CPO development. Quartz grain c-axis orientations of various domains within the cobbles and strain shadows indicate that CPO patterns are absent in both domains of dissolution and of precipitation irrespective of the degree of strain or metamorphic grade. The existence of discrete mica selvages along the cobble margins suggests that quartz dissolution only occurred along the cobble surface and did not affect the grains, or result in a CPO, within the cobble's interior. Quartz precipitation within the strain shadows did not result in a CPO, probably because the strain shadows are truly localized regions of low strain with little to no differential stress, allowing quartz grain growth in random orientations. / Thesis (MS) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Geology and Geophysics.

Previous perspective reparameterizations approximate the aliasing errors for the points in a 2D space---the points along the view direction (i.e. horizontal plane in view space), from a geometric intuition. There's no explicit way to qualitatively analyze the aliasing elsewhere. We thus derive the global representation of aliasing functions based on the solid mathematical analysis. Using the global representation, we propose the Direction-adaptive Perspective Shadow Maps (DirPSMs) to offer enhanced shadow rendering in real-time applications. / Shadows are essential for the realism of computer-generated images, which dramatically enhance our perception of virtual scenes by providing useful visual hints. Even tremendous advances in graphics rendering algorithms and programmable GPUs have made real-time and photo-realistic rendering a reality, the synthesis of realistic shadowing effects is still challenging and computationally intensive. Shadow mapping is one of the most popular algorithms for real-time shadow rendering, which has been extensively adopted in real-time applications by its generality and efficiency. However, shadow mapping suffers from the inherent aliasing problems such as jagged shadow boundaries and incorrect self-shadowing due to the image-based nature. In this thesis, we present several shadow rendering techniques to render anti-aliased shadows via shadow mapping especially for large-scale and dynamic scenes. / The Parallel-Split Shadow Maps (PSSMs) scheme is first proposed for realistic and real-time shadow rendering towards next generation of three-dimensional computer games. This scheme splits the view frustum into multiple parts using clip planes parallel to the view plane, and then generates multiple smaller shadow maps for the split parts. A fast and robust split strategy based on the analysis of shadow map aliasing is developed, to produce a moderate aliasing distribution over the whole depth range. Hardware-specific accelerations are also implemented and tested to remove the extra rendering passes caused by using multiple shadow maps. / These techniques are intuitive to implement without using complex data structures. They are designed to improve both quality and performance of shadow rendering in large-scale and dynamic scenes. / With the observation that the sampling density at the light in the post-perspective space better accommodates the requirements for the reconstruction of shadowed images, perspective reparameterization techniques warp shadow maps using the perspective transform to reduce aliasing errors for the objects near the viewer. One limitation in this line of research is that the approximated representation of aliasing errors is only valid for the ideal case in which the light and view directions are orthogonal. We thus establish the generalized perspective reparameterization functions to adaptively adjust the warping strength as the light and/or viewer moves. With the direction-dependent representations of aliasing errors, we subsequently develop three enhanced perspective reparameterizations to better handle general cases, including Generalized Linear Perspective Reparameterization (GLPR), Generalized Minimum-Norm Perspective Reparameterization (GMNPR) and Focus-preserving Trapezoidal Shadow Maps (FTSMs). / Zhang, Fan. / "August 2007." / Adviser: Hanqiu Sun. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1126. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 147-155). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

My abiding concern with human and planetary wellbeing and an emerging interest in the potential of Participatory Action Research as a method of engaging with restorative, life-enhancing ways of being are central to the research reported here. Chomsky (2003), Kelsey (2002), Roddick (2001), and Stiglitz (2003) are amongst many authors who argue that the way in which we shape and are shaped by our relationships with one another has contributed to an intolerable, inhumane and unsustainable compromise of human and planetary wellbeing. Through a Participatory Action Research (PAR) project with staff from Te Ra, a community based on the holistic ideals of Rudolf Steiner, and thus an organisation explicitly committed to holistic wellbeing of people and planet, we sought to explore the challenges to such wellbeing. While our mutual attention was focused on enhancing staff wellbeing at their place of employment, my wider attention was also given to an investigation of the value of a critical analysis to the wider political and economic context in which this organisation works to meet the aspirations of this community. My deep attention has also focused on the potential for PAR to make a contribution to the transformational aspirations of critical theorists who are concerned to uncover and transform aspects of society that inhibit justice and wellbeing of people and planet. My metaphor of choice, to allow me the engagement in all three spheres simultaneously, is the metaphor of Dance. In my work with the staff of Te Ra, our intent was to 'dance with the Shadows', alluding to Jungian references to hidden aspects of ourselves and this community, to discover if un-wellness and disconnection from self and others could be transformed into flourishing relationships and wellbeing in the organisation. McNiff (2000) proposes that PAR has the potential to generate living theories that redefine the main purpose of organisation theory in terms of human wellbeing. Throughout this research project, principles of PAR are woven in with work of critical organisational theorists, psychologists and anthropologists. The already established ideas of reflection, observation, reflexivity, and action are choreographed with the less often considered ideas of those aspects of the research relationship that may inhibit mutuality. While this organisation is explicitly and deeply committed to underpinning all that is aspired to with a relational ethic, the impact that instrumental practices associated with an intensifying neo-liberal economic external environment have not left this organisation untouched. It took commitment, courage and resources to identify and engage with the Shadows masked by intrinsic and extrinsic pressures and processes that these research participants were experiencing. Engaging in PAR processes allowed us dance 'up close and personal' with their aspirations to begin transforming what was not well, while recognising and reinforcing the organisation's existing strong philosophical and spiritual foundations that emphasized individual freedom and collective responsibility for wellbeing of all. Based on the significant transformations achieved during this project we posit that PAR provides a collaborative opportunity for academics and practitioners to 'dance with the Shadows' of individuals and communities to make a significant contribution to the development of sustainable relationships in workplaces where human and planetary wellbeing is the priority.

<p>Ultrasound (US) volume data is noisy, so traditional methods for direct volume rendering (DVR) are less appropriate. Improved methods or new techniques are required. There are furthermore a high performance requirement and limited pre-processing to be considered in order for it to be used interactively, since the volume data might be time-varying.</p><p>There exist numerous techniques for improving visual perception of volume rendering, and while some perform well and produce a visually enhanced result, many are designed and compared for use with medical data that has a high signal-to-noise ratio. This master thesis describe and compare recent methods for DVR illumination, in the form of ambient occlusion or direct/indirect lighting from an external light source. New designs and modifications are introduced for efficiently and effectively enhancing the visual quality of DVR with US data. Furthermore, this thesis addresses the issue of how clipping is performed during rendering and for the different illumination techniques, which is commonly used in ultrasound visualization.</p><p>This diploma work was conducted at Siemens Corporate Research in Princeton, NJ where the partially open source framework XIP is developed. The framework was extended further to include modern methods for DVR illumination that are described in detail within this thesis. Finally, presented results show that several methods can be used to visually enhance the visualization within highly interactive frame-rates.</p>

This thesis focuses on the oppositional and complimentary forces of light and shadows in the culture of Naples, Italy. Demonstrating, through photographs and the analysis of these photographs, how the light of Naples, a ‘northern’ light, and its resultant shadows echo (metaphorically and in reality) the light and shadows of the society, culture and history of Naples, Italy.

In the past, ray tracing has been used widely in offline rendering applications since it provided the ability to better capture high quality secondary effects such as reflection, refraction and shadows. Such effects are difficult to produce in a robust, high quality fashion with traditional, real-time rasterization algorithms. Motivated to bring the advantages to ray tracing to real-time applications, researchers have developed better and more efficient algorithms that leverage the current generation of fast, parallel CPU hardware within the past few years. This thesis provides the implementation and design details of a high performance ray tracing solution called ``RTTest'' for standard, desktop CPUs. Background information on various algorithms and acceleration structures are first discussed followed by an introduction to novel techniques used to better accelerate current, core ray tracing techniques. Techniques such as Omni-Directional Packets, Cone Proxy Traversal and Multiple Frustum Traversal are proposed and benchmarked using standard ray tracing scenes. Also, a novel soft shadowing algorithm called Edge Width Soft Shadows is proposed which achieves performance comparable to a single sampled hard shadow approach targeted at real time applications such as games. Finally, additional information on the memory layout, rendering pipeline, shader system and code level optimizations of RTTest are also discussed.

Ultrasound (US) volume data is noisy, so traditional methods for direct volume rendering (DVR) are less appropriate. Improved methods or new techniques are required. There are furthermore a high performance requirement and limited pre-processing to be considered in order for it to be used interactively, since the volume data might be time-varying. There exist numerous techniques for improving visual perception of volume rendering, and while some perform well and produce a visually enhanced result, many are designed and compared for use with medical data that has a high signal-to-noise ratio. This master thesis describe and compare recent methods for DVR illumination, in the form of ambient occlusion or direct/indirect lighting from an external light source. New designs and modifications are introduced for efficiently and effectively enhancing the visual quality of DVR with US data. Furthermore, this thesis addresses the issue of how clipping is performed during rendering and for the different illumination techniques, which is commonly used in ultrasound visualization. This diploma work was conducted at Siemens Corporate Research in Princeton, NJ where the partially open source framework XIP is developed. The framework was extended further to include modern methods for DVR illumination that are described in detail within this thesis. Finally, presented results show that several methods can be used to visually enhance the visualization within highly interactive frame-rates.

In the past, ray tracing has been used widely in offline rendering applications since it provided the ability to better capture high quality secondary effects such as reflection, refraction and shadows. Such effects are difficult to produce in a robust, high quality fashion with traditional, real-time rasterization algorithms. Motivated to bring the advantages to ray tracing to real-time applications, researchers have developed better and more efficient algorithms that leverage the current generation of fast, parallel CPU hardware within the past few years. This thesis provides the implementation and design details of a high performance ray tracing solution called ``RTTest'' for standard, desktop CPUs. Background information on various algorithms and acceleration structures are first discussed followed by an introduction to novel techniques used to better accelerate current, core ray tracing techniques. Techniques such as Omni-Directional Packets, Cone Proxy Traversal and Multiple Frustum Traversal are proposed and benchmarked using standard ray tracing scenes. Also, a novel soft shadowing algorithm called Edge Width Soft Shadows is proposed which achieves performance comparable to a single sampled hard shadow approach targeted at real time applications such as games. Finally, additional information on the memory layout, rendering pipeline, shader system and code level optimizations of RTTest are also discussed.