Efficient light scattering through thin semi-transparent objects

This paper concerns real-time rendering of thin semi-transparent objects. An object in this category could be a piece of cloth, eg. a curtain. Semi-transparent objects are visualized most correctly using volume rendering techniques. In general such techniques are, however, intractable for real-time applications. Surface rendering is more efficient, but also inadequate since semi-transparent objects should have a different appearance depending on whether they are front-lit or back-lit. The back-lit side of a curtain, for example, often seems quite transparent while the front-lit side seems brighter and almost opaque. To capture such visual effects in the standard rendering pipeline, Blinn [1982] proposed an efficient local illumination model based on radiative transfer theory. He assumed media of low density, hence, his equations can render media such as clouds, smoke, and dusty surfaces. Our observation is that Chandrasekhar [1960] has derived the same equations from a different set of assumptions. This alternative derivation makes the theory useful for realistic real-time rendering of dense, but thin, semitransparent objects such as cloth. We demonstrate that application of the theory in this new area gives far better results than what is obtainable with a traditional real-time rendering scheme using a constant factor for alpha blending

New Deal Art: California

Traditionally, the years of the New Deal projects have been treated as a part of the Depression experience with an emphasis on their economic and social dimensions. Until recently, sporadic interest in the art of the period has usually focused on individual artists, not general movements in the art of the time. This has been particularly true in the western states. The purpose of the New Deal Art: California exhibition was to create an overview of the New Deal art projects by bringing together examples of art from the federal art programs in California. New Deal Art: California came about as the result of a chance remark made, by Dr. Francis V. O\u27Connor, Art Historical Consultant, on his first trip to the de Saisset Art Gallery and Museum in 1971. The original exploratory research he did revealed a wealth of information about California\u27s contribution to the Works Progress Administration\u27s Federal Art Project and the Treasury Programs. Dr. O\u27Connor\u27s initial work helped provide the foundation for two years of subsequent research into the historical and aesthetic climate that gave birth to New ,Deal Art in California. The results of our explorations, in both quantity and quality of resources, has far exceeded our original expectations.https://scholarcommons.scu.edu/faculty_books/1367/thumbnail.jp

Real-time simulation and visualisation of cloth using edge-based adaptive meshes

Real-time rendering and the animation of realistic virtual environments and characters has progressed at a great pace, following advances in computer graphics hardware in the last decade. The role of cloth simulation is becoming ever more important in the quest to improve the realism of virtual environments. The real-time simulation of cloth and clothing is important for many applications such as virtual reality, crowd simulation, games and software for online clothes shopping. A large number of polygons are necessary to depict the highly exible nature of cloth with wrinkling and frequent changes in its curvature. In combination with the physical calculations which model the deformations, the effort required to simulate cloth in detail is very computationally expensive resulting in much diffculty for its realistic simulation at interactive frame rates. Real-time cloth simulations can lack quality and realism compared to their offline counterparts, since coarse meshes must often be employed for performance reasons. The focus of this thesis is to develop techniques to allow the real-time simulation of realistic cloth and clothing. Adaptive meshes have previously been developed to act as a bridge between low and high polygon meshes, aiming to adaptively exploit variations in the shape of the cloth. The mesh complexity is dynamically increased or refined to balance quality against computational cost during a simulation. A limitation of many approaches is they do not often consider the decimation or coarsening of previously refined areas, or otherwise are not fast enough for real-time applications. A novel edge-based adaptive mesh is developed for the fast incremental refinement and coarsening of a triangular mesh. A mass-spring network is integrated into the mesh permitting the real-time adaptive simulation of cloth, and techniques are developed for the simulation of clothing on an animated character

Rendering the Renaissance: A Methodology for Recreating Historical Fabrics and Fashions in Computer Graphics

Fabric and costume is an integral part of film media and increasingly so in computer graphics. There exists a growing interest in the creation of period films. To stay true to historical accuracy, creating believable, accurate costumes with appropriate fabric is key. While films such as Pixar’s Brave have made attempts at visual accuracy, there is little existing literature discussing a method of creating such costumes. This thesis aims to form a methodology and approach to historical costume using available technology, extant historical garments, period artist renderings and real world fabrics and sewing technique. To approach this problem, a focus time period and location was selected for review and recreation. Due to the amount of visual data available, mid 16th century Florence proved a desirable candidate. Existing software packages Maya, Marvelous Designer, Mental Ray and Renderman were used for modeling, simulation and rendering respectively in order to execute the final product. The end goal was to render a model of a Florentine dress with identifiable fabrics using the designed methodology. An additional goal was to demonstrate a variety of fabric shaders to illustrate fabrics found during this period such as wool, linen, silk and velvet. The resulting renders represented visual accuracy to the sources used. Applications for this methodology can include film, games, historical documentation and education

(Re)fashioning Biafra: identity, authorship and the politics of dress in half of a yellow sun and other narratives of the Nigeria-Biafra war

Chimamanda Ngozi Adichie’s second novel, Half of a Yellow (2006), is one in a long line of works by Nigerian authors to portray the Nigeria-Biafra War (1967-1970). While Adichie has stated that she wanted to make modern Nigeria aware of its history by writing the novel, the writer has also revealed that she drew from past literary portrayals to construct her narrative. In order to untangle the complex construction of Half of a Yellow Sun, this article explores the way the novel negotiates the literary legacy of Biafra through material fashion, which I argue elucidates this complex intertextuality. Furthermore, I contend that the novel draws attention to and critiques the way that understanding of Biafra has been dominated by novels written by male authors, and weaves threads of material fashion in order to offer a new way of negotiating Nigerian history

Skin-touch-actuated textile-based triboelectric nanogenerator with black phosphorous for durable biomechanical energy harvesting

Textiles that are capable of harvesting biomechanical energy via triboelectric effects are of interest for self-powered wearable electronics. Fabrication of conformable and durable textiles with high triboelectric outputs remains challenging. Here we propose a washable skin-touch-actuated textile-based triboelectric nanogenerator for harvesting mechanical energy from both voluntary and involuntary body motions. Black phosphorus encapsulated with hydrophobic cellulose oleoyl ester nanoparticles serves as a synergetic electron-trapping coating, rendering a textile nanogenerator with long-term reliability and high triboelectricity regardless of various extreme deformations, severe washing, and extended environmental exposure. Considerably high output (~250–880 V, ~0.48–1.1 µA cm−2) can be attained upon touching by hand with a small force (~5 N) and low frequency (~4 Hz), which can power light-emitting diodes and a digital watch. This conformable all-textile-nanogenerator is incorporable onto cloths/skin to capture the low output of 60 V from subtle involuntary friction with skin, well suited for users’ motion or daily operations