Rendering

Until recently, depth sensing cameras have been used almost exclusively in research due to the high costs of such specialized equipment. With the introduction of the Microsoft Kinect device, realtime depth imaging is now available for the ordinary developer at low expenses and so far it has been received with great interest from both the research and hobby developer community. The underlying OpenNI framework not only allows to extract the depth image from the camera, but also provides tracking information of gestures or user skeletons. In this paper, we present a framework to include depth sensing devices into X3D in order to enhance visual fidelity of X3D Mixed Reality applications by introducing some extensions for advanced rendering techniques. We furthermore outline how to calibrate depth and image data in a meaningful way through calibration for devices that do not already come with precalibrated sensors, as well as a discussion of some of the OpenNI functionality that X3D can benefit from in the future.

This work describes the properties of plastics made from partially denatured proteins produced by the animal coproduct (rendering) industry and these plastics' fabrication. Specifically, plastic samples from partially denatured feathermeal protein were successfully produced by a compression-molding process. The modulus (stiffness) of the material obtained was found to be comparable with that of commercial synthetic materials, such as polystyrene, but was found to have lower toughness characteristics, which is a common phenomenon among plastics produced from animal and plant proteins. A reversible stress-strain property was observed over the yield region. Plastic-forming conditions for undenatured animal proteins, such as albumen and whey proteins, were also formulated for fabricating plastics out of these proteins' blends with feathermeal proteins. The resultant plastic samples that were developed of biomacromolecular blends, such as feathermeal/whey and feathermeal/ albumen, demonstrated improved mechanical properties, specifically tensile strength, when compared with neat plastics from feathermeal proteins. The values for the stiffness of the feathermeal/whey blends deviated from simple mixing rule and showed a synergistic effect.

Several natural phenomena, such as mirages or the green flash, are owed to inhomogeneous media in which the index of refraction is not constant. This makes the light rays travel a curved path while going through those media. One way to simulate global illumination in inhomogeneous media is to use a curved ray tracing algorithm, but this approach presents some problems that still need to be solved. This paper introduces a full solution to the global illumination problem, based on what we have called curved photon mapping, that can be used to simulate several natural atmospheric phenomena. We also present a model of the Human Visual System (HVS) to display images in a more realistic way, taking into account how we perceive luminances in a real-world scene. This is of special interest in the green flash effect, where some of the perceived green is owed to bleaching of the photoreceptors in the human eye.

helpful comments during the preparation of this dissertation. I would like to thank Professor Paul Adams for the use of his lab and equipment. I would also like to acknowledge the efforts of the system and administration staff in the department. In particular, I would like to thank Brian Tria for maintaining the systems and answering many questions, and Kathy Germanai, Betty Knittweis, and Stella Mannino for all the paper work and administrative details that they took care of on my behalf. I would like to thank the numerous individuals who have giv en me inv aluable comments and insights during my research − Dany Cohen, Taosong He, Lichan Hong, Hanspeter Pfister, Claudio Silva, Sidney Wang, and Roni Yagel. I would also like to thank the many people who have worked on the development of the VolVis system −

Human irises gain their appearance from a layered and highly complex structure that is difficult to model and render with conventional techniques. We present an approach that uses domain knowledge from the field of ocular prosthetics. In that field, ocularists create an artificial iris by painting many simple semi-transparent layers. We translate this methodology into a simple and effective toolkit which can be used to create and render realistic looking irises.

This paper describes a method for modeling the natural peeling phenomenon over any 3D surface. Using crack input data-precomputed with a semi-physical solution-this method allows simulating peeling on any type of triangulated 3D object. Our model's main advantage is that it proposes an method that is intuitive enough to make it easy to understand and convenient to apply, user controllable, and easily extensible-especially to simultaneous natural phenomena. We first introduce the general development of peeling over various materials. Then, we present how to define groups of peeling, how to determine a realistic and natural peeling order, and how to simulate the rendering of two types of special peelings. Finally, a set of graphical results concludes the paper, presenting a series of direct peeling and curling patterns using classical paintings or plastic-paintings simulated materials.

Real-time results of our method for simulating translucent materials (skin on the left, ketchup on the right). Our separable subsurface-scattering method enables the generation of these images using only two convolutions (versus 12 in the sum-of-Gaussians approach [dLE07, JSG09]) and seven samples per pixel, while featuring quality comparable with the current state of the art, at a fraction of its cost. It can be implemented as a post-processing step and takes only 0.489 ms per frame on an AMD Radeon HD 7970 at 1080p, which makes it highly suitable for challenging real-time scenarios. Abstract In this paper we propose two real-time models for simulating subsurface scattering for a large variety of translucent materials, which need under 0.5 milliseconds per frame to execute. This makes them a practical option for real-time production scenarios. Current state-of-the-art, real-time approaches simulate subsurface light transport by approximating the radially symmetric non-separable diffusion kernel with a sum of separable Gaussians, which requires multiple (up to twelve) 1D convolutions. In this work we relax the requirement of radial symmetry to approximate a 2D diffuse reflectance profile by a single separable kernel. We first show that low-rank approximations based on matrix factorization outperform previous approaches, but they still need several passes to get good results. To solve this, we present two different separable models: the first one yields a high-quality diffusion simulation, while the second one offers an attractive trade-off between physical accuracy and artistic control. Both allow rendering subsurface scattering using only two 1D convolutions, reducing both execution time and memory consumption, while delivering results comparable to techniques with higher cost. Using our importance-sampling and jittering strategies, only seven samples per pixel are required. Our methods can be implemented as simple post-processing steps without intrusive changes to existing rendering pipelines.

The purpose of this project was to create several methods for achieving non-photorealistic appearance of the objects or, in other words, the goal was to create several different implementations of the cartoonish shader, which can sometimes be referred to as a cel-shader or just toon-shader.

This paper presents a survey of ocean simulation and rendering methods in computer graphics. To model and animate the ocean's surface, these methods mainly rely on two main approaches: on the one hand, those which approximate ocean dynamics with parametric, spectral or hybrid models and use empirical laws from oceanographic research. We will see that this type of methods essentially allows the simulation of ocean scenes in the deep water domain, without breaking waves. On the other hand, physically-based methods use Navier-Stokes Equations (NSE) to represent breaking waves and more generally ocean surface near the shore. We also describe ocean rendering methods in computer graphics, with a special interest in the simulation of phenomena such as foam and spray, and light's interaction with the ocean surface.

Este trabajo de investigación propone el estudio, análisis y desarrollo del proceso de diseño arquitectónico y su posible variabilidad determinada por el uso de técnicas y herramientas digitales de diseño.

Frente a esto se define como la problemática inicial a la ‘discretización del diseño arquitectónico’ entendida como la divergencia entre los procesos tradicionales de diseño arquitectónico frente a la sistematización racional, como mecanismo de búsqueda arquitectónica, que proponen actualmente las nuevas herramientas digitales de diseño.

These slides describes about rendering engine, types of rendering engine and how Webkit rendering works.
A rendering engine (also called layout engine or web browser engine) is a software component that takes marked up content (like HTML, XML, image files, etc.) and formatting information (like CSS, XSL, etc.) and displays the formatted content on the screen

Selamat datang kembali di saidgank , dalam artikel ini saya ingin menjelaskan cara membuat bahan air di V-Ray , kita gunakan settingan tersebut buat laut , danau , sebuah kolam renang agar semakin terlihat nyata saat di render seperti gambar dibawah ini. Jadi mari kita mulai. Yang harus kalian lakukan untuk membuat agar realistis adalah untuk pertama buka Material Editor dari V-Ray dan membuat material baru, mengganti nama dengan nama yang paling sesuai dengan apa yang ingin Anda capai, misalnya, saya telah menganti menjadi air karena, seperti yang Anda lihat di 'gambar saya di atas seperti air laut, tapi kalian dapat mengantinya seperti apa yang kalian inginkan ...berikut ini adalah caranya: tutorial cara membuat air agar terlihat realistis di vray sketchup

Özet: Dijital Teknolojiler, Üç boyutlu görselleştirme Programları, farklı modelleme yöntemleri diğer mühendislik alanlarında olduğu gibi mimarlık alanında da yoğun bir şekilde kullanılmaktadır. Bu çalışmada Maltepe Üniversitesi Mimarlık ve Tasarım Fakültesinde İç Mimarlık Bölümü Yüksek lisans programında yürütülen bir projenin modeli ve modele geçiş süreci ele alınacaktır. Proje konusu Kadıköy'de bir "Seramik Kafe" tasarımıdır. Kafe projesi aynı zamanda bir atöyle-toplanma yeri, seminer ve workshopların yapıldığı bar ve satış birimini de içeren çok amaçlı bir mekan projesi tasarımıdır. Bu çalışma seramik bölümü mezunu ödüllü bir tasarımcı olan Berk Arıl ile yürütücüsü mimar Türkan İrgin Uzun'un ürünüdür. Projede kullanılan 3d Max programının kısa tarihçesine de değinilerek, proje ile paralel sürdürülen modelleme teknikleri, öğrenme sürecinin tasarımcının görselleştirme becerisine katkıları, sahneye nasıl yansıttığı, tasarımlarında nasıl kullanabildiği gibi konularda elde edilen sonuçların sunulacağı ve değerlendirileceği örnek bir çalışma modelidir. Çalışmada Seramik kafenin tasarım kararları, 3d modele aktarımı, malzeme seçimi, ışık ayarlarıyla birlikte bitmiş bir tasarımın, sahne donatılarının kararları ve sonuçları modellemenin görsel sonuçlarıyla birlikte sunulacaktır. Anahtar Sözcükler: Dijital tasarım, dijital modelleme, dijital görselleştirme, 3d Max, iç mekan, mimari modelleme, mimari görselleştirme, mimarlık , iç mimarlık, iç mekan, seramik atölyesi, yüksek lisans projesi

Abstract: Digital Technology, Three-dimensional visualization program, different modeling methods are used extensively in architecture, as in other engineering fields. In this study, Maltepe University Faculty of Architecture and Design, Department of Interior Architecture model and model transition to a project carried out in the master program will be discussed. A project topic in Kadikoy "Ceramic Café" design. Café project also workshop to-one meeting place, including seminars and workshops, bars and sales units in which the project is a multipurpose interior design. In the short history of 3d Max software used in the project reference, the project in parallel with the ongoing modeling techniques, the learning process of visualization skills to contribute to the designer, how it reflects on the scene, how they can use in the design, it will be presented the results obtained in the subject and sample to be evaluated is a working model. Work on ceramics cafe design decisions, 3d model transfer, material selection, with light setting a finished design, decisions and results of the modeling stage equipment will be presented with the visual results.

L’obiettivo di questo studio è la visualizzazione digitale del modello di un’opera giovanile di Almeyda: il
caffè del 1859.
La tavola originale, su cartoncino, raffigura la pianta del livello principale ed un prospetto.
La riproduzione è avvenuta tramite scansioni piane di formato A3 ad alta risoluzione, effettuate con un
buon margine di sovrapposizione e moisacate in modo non automatico, poiché il risultato della
composizione automatica presentava, in alcuni casi, operazioni di sovrapposizione ritenuti non
accettabili.
Il progetto del caffè si sviluppa su un nucleo centrale a forma di ottagono regolare. Lo schema,
perfettamente centrico, presenta, lungo i due assi ortogonali principali, quattro vestiboli rettangolari
con gruppo tetrastilo centrale e quattro nicchie murarie. Lungo gli assi diagonali si trovano quattro vani
rettangolari chiusi da piccoli spazi emisferici.
Il modello tridimensionale mette in risalto una composizione volumetrica molto complessa, non
immediatamente percepibile da pianta e prospetto, che si alleggerisce verso l’alto, fino alla copertura
piramidale, matericamente alleggerita dalla struttura in ferro e vetro.
Le informazioni contenute nei disegni originali consentono la modellazione del paramento esterno del
caffè, mentre è impossibile, in assenza di sezioni, la ricostruzione degli interni.
Il modello tridimensionale è stato utilizzato come base per rendering statici, per un’animazione e per
una visualizzazione navigabile interattiva.

In this paper, we introduce a novel approach for modeling surface reflection. We focus on using a family of probability distributions called Archimedean copulas as BRDF models. The Archimedean representation has an attractive property in that the multivariate distributions are characterized by their marginal distributions through a single univariate function only. It is shown that the proposed model meets the reciprocity property of reflection. Based on measured BRDF data, we demonstrate that the proposed approach provides a good approximation to BRDF. Empirical comparisons are made with some classically used BRDF models.

Obscurances is a powerful technique that approximates indirect global illumination in a much faster way than classic methods as radiosity or path tracing. In this method, the local environment of a point or a patch is sampled to estimate the amount of occlusion that surrounds it. Fine effects as color reflection can be added and visually pleasant rendering of corners and soft shadows are easily computed. Combined with ray tracing techniques, nondiffuse and specular effects can be added to the surfaces, obtaining thus beautiful and realistic rendered images. Since direct and indirect illumination are decoupled, obscurances are very useful to render animation frames for moving light sources, as they have to be computed only for the first frame and then reused. Ambient light intensity can also be decoupled from obscurances and estimated for every frame, resulting in beautiful colorchanging effects. Light animation help in light design and to convey shape and features of the objects in the scene.

This essay is part of a special, guest edited issue of "The Journal of Architectural Education" entitled "#SMLXL." This special issue's publication coincided, down to the month, with the 20th anniversary of the publication of the Office for Metropolitan Architecture's self-described 1,000+ page architectural novel," "S, M, L, XL"

Global lighting effects produced by diffuse interreflections are typically simulated using global illumination methods such as radiosity or ray tracing. Although diffuse interreflections are crucial to produce realistic images, radiosity-like methods are rarely used in production rendering because of slow performance, robustness problems and difficulty-to-control. We present a novel technology that produces natural-looking lighting effects in a much faster way than radiosity and ray tracing. The solution is view-independent, and can be used in 3D real-time interactive applications, as well as for high-quality production rendering. Our method simulates global illumination solution using the ambient light illumination model based on obscurances. The technology outlines surface profile even without light sources, making it easy to rapidly compute realistically looking images. The simulation of ambient light distribution saves both light sources setting and rendering times. The results of computations are stored in texture maps, which allows storing multiple light samples per polygon without explicit meshing. This is vital in 3D real-time applications, and speeds up rendering in 3D animation packages as well. Once computed, obscurance maps allow for rapid re-computation of the illumination solution for moving light sources and for scenes with animated objects.

The occurrence of false-positives (FPs) is still an important concern and source of unreliability in computer-aided diagnosis systems developed for 3D virtual colonoscopy. This work presents three different supervised approaches, based on supervised artificial neural networks (ANNs) architectures tested on 16 rows helical multi-slice computer tomography. The performance of the best ANN architecture developed, by using the volumes belonging to only 4 of 7 available nodules diagnosed by expert radiologists as polyps and non-polyps were evaluated in terms of FPs and false-negatives. It revealed good performance in terms of generalization and FPs reduction, correctly detecting all 7 polyps.

En este texto se analiza el potencial de la figura humana,
dentro del dibujo en perspectiva, como una herramienta de comunicaciÛn
del proyecto de arquitectura. Como se sabe, aunque en la representaciÛn
arquitectÛnica actual
heredera de los estilos gr·ficos y modelÌsticos
del pasado, ligada a las herramientas digitales y condicionada por el
marketing
el uso de figuras humanas es extendido, en la mayorÌa de
los estudios, Èstas son empleadas para ambientar y mostrar la escala del
edificio, sin mayores pretensiones. No obstante, en algunas ocasiones
su utilizaciÛn va m·s all·, siendo original y totalmente intencionada,
hacia destacar ciertos contenidos del proyecto m·s personales del autor.
De esta forma, adem·s de evidenciar la proporciÛn de la arquitectura
ideada, las im·genes humanas pueden ser el elemento que indique su
cometido; las caracterÌsticas del medio fÌsico; los perfiles de usuarios
que se espera se apropien del proyecto; las escenas habituales que se
generar·n en el espacio; el concepto global; y el espÌritu de la Època. Es
intenciÛn de este documento seleccionar, analizar y sintetizar diferentes
categorÌas de uso, donde las figuras humanas act˙an como elementos
polisÈmicos que matizan el discurso
tanto publicitario como crÌtico
e histÛrico
del proyecto de arquitectura.

In designing graphical workstations for high-level performance presentations of graphical models, the main goal nowadays is to perform some effective real-time traversal and rendering of data. In this paper we present a reference model of parallel processing for graphics, taking into account the main aspects of colour rendering of solid hierarchical shapes; i.e., traversal of structures, hidden surfaces removal, shadow identification and Light models. In particular, a pardel design of the main graphical algorithms is presented. Three abstract machines are proposed, designed respectively for data structure traversing, for depth ordering and shadows computation and finally for shape merging and screen procesSing. Such abstract machines, internally parallel, may be combined in various ways to define different physical architectures.

This paper presents a fast approximation method to obtain the point hit by a reflection or refraction ray. The calculation is based on the distance values stored in environment map texels. This approximation is used to localize environment mapped reflections and refractions, that is, to make them depend on where they occur. On the other hand, placing the eye into the light source, the method is also good to generate real-time caustics. Computing a map for each refractor surface, we can even evaluate multiple refractions without tracing rays. The method is fast and accurate if the scene consists of larger planar faces, when the results are similar to that of ray-tracing.

The transition from traditional graphics into computer graphics over the past decade has brought about a multitude of changes that graphics educators and other graphics professionals have had to address and incorporate. The ever evolving integration of computer aided design (CAD) in architecture and engineering have revolutionized the design and documentation process. In the graphic communication area, changes from layout and design to desktop publishing and interactive `new media' design for CD-ROM and Web distribution are but a few of the changes graphic educators have to keep up with. One problem with new technology is computer graphics encompasses several components and areas, and some of these areas are not able to progress into technology as quickly as others. This paper gives an overview of the shades, shadows and perspective course at Purdue University and how it has evolved into an integrated 2D and 3D digital lighting and rendering illustration course

Generating photo-realistic images through Monte Carlo rendering requires efficient representation of light–surface interaction and techniques for importance sampling. Various models with good representation abilities have been developed but only a few of them have their importance sampling procedure. In this paper, we propose a method which provides a good bidirectional reflectance distribution function (BRDF) representation and efficient importance sampling procedure. Our method is based on representing BRDF as a function of tensor products. Four-dimensional measured BRDF tensor data are factorized using Tucker decomposition. A large data set is used for comparing the proposed BRDF model with a number of well-known BRDF models. It is shown that the underlying model provides good approximation to BRDFs.

In this paper, we present a new system of non-photorealistic rendering which allows landscape photographs to be automatically converted to look like Oriental paintings. Using various computer vision and image processing techniques, we can generate images with the rules and features commonly found in Oriental paintings. With such a system, anyone can create realistic Oriental paintings easily, without the years of practice that are usually required by Oriental artists.

The paper introduces a new approximate method for rendering translucent materials. We represent the surface around a point to be rendered in Monge's form using principal curvatures. The subsurface reflectance equation in the dipole diffusion approximation is then integrated over the surface. The outgoing radiance at the point is expressed as a function of principal curvatures and light vector components along the principal directions. This function can be precomputed as a 2D lookup table, which can be stored as a texture image. The paper presents preliminary results of our work on implementation of the model described.

In this paper, we present a new SH operation, called spherical harmonics scaling, to shrink or expand a spherical function in the frequency domain. We show that this problem can be elegantly formulated as a linear transformation of SH projections, which is efficient to compute and easy to implement on a GPU. Spherical harmonics scaling is particularly useful for extrapolating visibility and radiance functions at a sample point to points closer to or farther from an occluder or light source. With SH scaling, we present applications to low-frequency shadowing for general deformable object, and to efficient approximation of spherical irradiance functions within a mid-range illumination environment.

Dalam dunia multimedia, terkadang dibutuhkan suatu perangkat lunak untuk melakukan proses rendering pembuatan video atau animasi. Proses tersebut sangat bergantung pada kinerja performa dari komputer yang digunakan untuk dapat bekerja secara cepat serta gambar atau animasi yang dihasilkan memiliki kualitas baik. Hal tersebut sulit dipenuhi jika gambar atau animasi yang akan diproses memiliki tingkat kompleksitas yang sangat tinggi dan memiliki banyak frame. Untuk mengatasi masalah tersebut dikemukakannya parallel rendering untuk memanfaatkan sumber daya yang terbagi dalam beberapa komputer secara paralel sebagai suatu rendering farm. Pada makalah ini, akan dibahas mengenai analisa perbandingan antara proses sequential rendering dan parallel rendering yang bertujuan untuk mengetahui proses mana yang dapat mengeksekusi proses render secara lebih cepat dalam menghasilkan gambar atau animasi pada aplikasi Blender.

In this article we use an ElectroEncephaloGraph (EEG) to explore the perception of artifacts that typically appear during rendering and determine the perceptual quality of a sequence of images. Although there is an emerging interest in using an EEG for image quality assessment, one of the main impediments to the use of an EEG is the very low Signal-to-Noise Ratio (SNR) which makes it exceedingly difficult to distinguish neural responses from noise. Traditionally, event-related potentials have been used for analysis of EEG data. However, they rely on averaging and so require a large number of participants and trials to get meaningful data. Also, due the the low SNR ERP's are not suited for single-trial classification. We propose a novel wavelet-based approach for evaluating EEG signals which allows us to predict the perceived image quality from only a single trial. Our wavelet-based algorithm is able to filter the EEG data and remove noise, eliminating the need for many participa...

Visualizations play a significant role as decision-making tools in planning processes. Nowadays perspective representations -3D renders- are commonly used. However, we argue that in order to perceive depth, size, and detail; a “virtuality”: intensity, immersion, and interactivity have to be addressed. Technologies such as Virtual Reality (VR) create this “virtuality”, enabling the user to not only view the digital environment in 3D but also to look around and experience the space. 
   
In this research, we propose a pipeline to visualize big scale landscape projects with laser scan’ point cloud models and virtual reality as a medium to communicate. The pipeline combines five software, Rhino, Cinema 4D, Cloud Compare, and Unity. 

The method is applied in one case-study joining two representation, an interactive point cloud model, and specific 360 degrees renders. The resulting experience is one where the users can repeatedly visit the site, viewing it from angles impossible in the real world and allows them to have a better understanding of the project.

Various empirical and theoretical models of the surface reflectance have been introduced so far. Most of these models are based on functions with non-linear parameters and therefore faces some computational difficulties involved in non-linear optimization processes. In this paper, we introduce a new approach for approximating Bidirectional Reflectance Distribution Functions (BRDF) by employing response surface methodology. The proposed model employs principal component transformations of the explanatory variables which are essentially functions of incoming and outgoing light directions. The resulting model is linear and can be used to represent both isotropic and anisotropic reflectance for diffuse and glossy materials. Considering some widely used reflection models including the Ward model, the Ashikhmin–Shirley model and the Lafortune model, we demonstrate empirically that satisfactory approximations can be made by means of the proposed general, simple and computationally efficient linear model.

Domain Analysis for Data Visualization (DADV) is a technique to use when investigating a domain where data visualizations are going to be designed and added to existing software systems. DADV was used to design the data visualization in VisEIO-LCA, which is a framework to visualize environmental data about products. Most of the visualizations are designed using the following stages: formatting data in tables, selecting visual structures, and rendering the data on the screen. Although many visualizations authors perform implicit domain analysis, in this paper, domain analysis is added explicitly to the process of designing visualizations with the goal of producing more usable software tools. Environmental Life-Cycle Assessment (LCA) is used as a test bed for this technique.

B-Splines in general, and Non-Uniform Rational B-Splines in particular, have become indispensable modeling primitives in computer graphics and geometric modeling applications. In this paper a novel high-performance architecture for the computation of uniform, non-uniform, rational and non-rational B-Spline curves and surfaces is presented. This architecture has been derived through a sequence of steps. First, a systolic architecture for the computation of the basis function values, the basis function evaluation array (the BFEA), is developed. Using the BFEA as its core, an architecture for the computation of non-uniform rational B-Spline curves is constructed. This architecture is then extended to compute NURBS surfaces. Finally, this architecture is augmented to compute the surface normals so that the output from this architecture can be directly used for rendering the NURBS surface. The overall linear structure of the architecture, its small I/O requirements, its non-dependence on the size of the problem (in terms of the number of control points and the number of points on the curve/surface that has to be computed), and its very high throughput make this architecture highly suitable for integration into the standard graphics pipeline of high-end workstations. Results of the timing analysis indicate a potential throughput of one triangle with the normal vectors at its vertices, every two clock cycles.

We describe a new framework for efficiently computing and storing global illumination effects for complex, animated environments. The new framework allows the rapid generation of sequences representing any arbitrary path in a "view space" within an environment in which both the viewer and objects move. The global illumination is stored as time sequences of range-images at base locations that span the view space. We present algorithms for determining locations for these base images, and the time steps required to adequately capture the effects of object motion. We also present algorithms for computing the global illumination in the base images that exploit spatial and temporal coherence by considering direct and indirect illumination separately. We discuss an initial implementation using the new framework. Results and analysis of our implementation demonstrate the effectiveness of the individual phases of the approach; we conclude with an application of the complete framework to a complex environment that includes object motion.

Global lighting effects produced by diffuse interreflections are typically simulated using global illumination methods such as radiosity or ray tracing. Although diffuse interreflections are crucial to produce realistic images, radiosity-like methods are rarely used in production rendering because of slow performance, robustness problems and difficulty-to-control. We present a novel technology that produces natural-looking lighting effects in a much faster way than radiosity and ray tracing. The solution is view-independent, and can be used in 3D real-time interactive applications, as well as for high-quality production rendering. Our method simulates global illumination solution using the ambient light illumination model based on obscurances. The technology outlines surface profile even without light sources, making it easy to rapidly compute realistically looking images. The simulation of ambient light distribution saves both light sources setting and rendering times. The results of computations are stored in texture maps, which allows storing multiple light samples per polygon without explicit meshing. This is vital in 3D real-time applications, and speeds up rendering in 3D animation packages as well. Once computed, obscurance maps allow for rapid re-computation of the illumination solution for moving light sources and for scenes with animated objects.

ABSTRACT The servomotors used in the joints of a manipulator or wheels of a rover in high risk applications, such as space applications, should be capable of continued functional operation even if insulation failure or open-circuit of a winding occur. This paper presents a fault-tolerant (FT) torque con troller for brushless motors that can maintain accurate torque production with minimum power dissipation subject to current limitations even if one of motor phases fails. The controller is developed based on the Fourier series model of the motor back-EMF waveform and the cogging torque. The faulty phase is detected from the covariance of the estimation error of a voltage observer. Subsequently, the phase currents of the remaining phases are optimally reshaped so that the motor accurately generates torque as requested while minimizing power loss subject to maximum current limitation of the current amplifiers. A closed-form solution to the optimization programming problem is found by using the Kuhn-Tucker theorem; rendering the control approach suitable for real-time implementation. Experimental results illustrate the capability of the FT controller to achieve ripple-free torque performance during a phase failure at the expenses of increasing the mean power loss by 28%.