319 research outputs found
Rethinking texture mapping
No full textThe intrinsic problems of standard Texture Mapping, regarding UV-maps and seams, are well-known, but often considered unavoidable. In this course we will discuss various radically diferent ways to rethink texture mapping that have been proposed over decades, each ofering diferent advantages and trade-offs
Efficient Adaptive Deferred Shading with Hardware Scatter Tiles
No full textAdaptive shading is an effective mechanism for reducing the number of shaded pixels to a subset of the image resolution with minimal impact on final rendering quality. We present a new scheduling method based on on-chip tiles that, along with relatively minor modifications to the GPU architecture, provides efficient hardware support. As compared to software implementations on current hardware using compute shaders, our approach dramatically reduces memory bandwidth requirements, thereby significantly improving performance and energy use. We also introduce the concept of a fragment pre-shader for programmatically controlling when a fragment shader is invoked, and describe advanced techniques for utilizing our approach to further reduce the number of shaded pixels via temporal filtering, or to adjust rendering quality to maintain stable framerates.Proceedings of the ACM on Computer Graphics and Interactive TechniquesHigh-Performance Rendering3
Quadratic Approximation of Cubic Curves
No full textWe present a simple degree reduction technique for piecewise cubic polynomial splines, converting them into piecewise quadratic splines that maintain the parameterization and C1 continuity. Our method forms identical tangent directions at the interpolated data points of the piecewise cubic spline by replacing each cubic piece with a pair of quadratic pieces. The resulting representation can lead to substantial performance improvements for rendering geometrically complex spline models like hair and fiber-level cloth. Such models are typically represented using cubic splines that are C1-continuous, a property that is preserved with our degree reduction. Therefore, our method can also be considered a new quadratic curve construction approach for high-performance rendering. We prove that it is possible to construct a pair of quadratic curves with C1 continuity that passes through any desired point on the input cubic curve. Moreover, we prove that when the pair of quadratic pieces corresponding to a cubic piece have equal parametric lengths, they join exactly at the parametric center of the cubic piece, and the deviation in positions due to degree reduction is minimized.Proceedings of the ACM on Computer Graphics and Interactive TechniquesRendering Thin or Transparent Objects3
Compacted CPU/GPU Data Compression via Modified Virtual Address Translation
No full textWe propose a method to reduce the footprint of compressed data by using modified virtual address translation to permit random access to the data. This extends our prior work on using page translation to perform automatic decompression and deswizzling upon accesses to fixed rate lossy or lossless compressed data. Our compaction method allows a virtual address space the size of the uncompressed data to be used to efficiently access variable-size blocks of compressed data. Compression and decompression take place between the first and second level caches, which allows fast access to uncompressed data in the first level cache and provides data compaction at all other levels of the memory hierarchy. This improves performance and reduces power relative to compressed but uncompacted data. An important property of our method is that compression, decompression, and reallocation are automatically managed by the new hardware without operating system intervention and without storing compression data in the page tables. As a result, although some changes are required in the page manager, it does not need to know the specific compression algorithm and can use a single memory allocation unit size. We tested our method with two sample CPU algorithms. When performing depth buffer occlusion tests, our method reduces the memory footprint by 3.1x. When rendering into textures, our method reduces the footprint by 1.69x before rendering and 1.63x after. In both cases, the power and cycle time are better than for uncompacted compressed data, and significantly better than for accessing uncompressed data.Proceedings of the ACM on Computer Graphics and Interactive TechniquesHardware Architectures and Space Partitioning3
Hardware-Accelerated Dual-Split Trees
No full textBounding volume hierarchies (BVH) are the most widely used acceleration structures for ray tracing due to their high construction and traversal performance. However, the bounding planes shared between parent and children bounding boxes is an inherent storage redundancy that limits further improvement in performance due to the memory cost of reading these redundant planes. Dual-split trees can create identical space partitioning as BVHs, but in a compact form using less memory by eliminating the redundancies of the BVH structure representation. This reduction in memory storage and data movement translates to faster ray traversal and better energy efficiency. Yet, the performance benefits of dual-split trees are undermined by the processing required to extract the necessary information from their compact representation. This involves bit manipulations and branching instructions which are inefficient in software. We introduce hardware acceleration for dual-split trees and show that the performance advantages over BVHs are emphasized in a hardware ray tracing context that can take advantage of such acceleration.We provide details on how the operations needed for decoding dual-split tree nodes can be implemented in hardware and present experiments in a number of scenes with different sizes using path tracing. In our experiments, we have observed up to 31% reduction in render time and 38% energy saving using dual-split trees as compared to binary BVHs representing identical space partitioning.Proceedings of the ACM on Computer Graphics and Interactive TechniquesHardware Architectures and Space Partitioning3
Cross-border Litigation in Europe: Some Theoretical Issues and Some Practical Challenges
No full textThis is the author accepted manuscript. The final version is available from Hart Publishing via the link in this record
Customer satisfaction of dining experience in Malaysian malay restaurants.
No full textThe subject of this Ph.D. thesis is Customer Satisfaction in Malaysian Malay Restaurants Dining Experience. The research was conducted in three Malay family restaurants in Malaysia by using an inductive Case Study research approach. The aim of the research was to propose a conceptual framework for customer satisfaction dining experience. It focused on dining experience satisfaction consumption related to factors in, and the management of, customer satisfaction. The implications of the findings provide a theoretical and methodological contribution to the knowledge in both, Malaysia and the rest of the world. Adopting the Case Study research approach gave an opportunity to collect data that stems from three Malay family restaurants in Malaysia using a wide variety of data collection methods. The findings presented in this thesis were based on an in-depth interview with 108 restaurant customers who dined at the restaurants and 18 restaurant staff, particularly front of house and kitchen staff, besides the owner and manager of each restaurant. Daily participant observation for each restaurant took 5 to 9 hours a day for between 27 and 30 days. The findings were also based on a number of supplementary data from documentary evidence such as staff working timetables, menu cards/ books, staff attendance punch cards, stock check lists, reservation records and restaurant organisational charts. The contributions of this study comprise of six major themes: Firstly, dining experience is a continuous process which starts with the customers’ first engagement with the restaurant at the reservation stage and continues until they leave the restaurant at the departure stage. Therefore, to ensure customers’ loyalty, restaurateurs needed to ensure all tangible and intangible factors that influenced satisfaction at each stage of the dining process (pre-meal experience; antecedent experience; reservation experience and arrival experience; the actual meal experience: seating experience and food experience; and post-meal experience: payment experience and departure experience) were integrated together (they did not work as separate entities and should not be treated individually) to provide valuable, meaningful, memorable and holistic satisfaction to every customer who dined at the restaurant. Secondly, factors influencing customer satisfaction at the pre-meal experience were the availability of a reservation service, both formal and informal, and customers’ phone calls for reservations being answered quickly by restaurants’ polite and professional staff. Meanwhile, at the dining arrival stage, factors influencing customers’ satisfaction were being assisted by a free parking attendant, having a parking area close to the premises, punctuality of restaurant business hours and offering a 24-hour restaurant operation to the public. The meal experience stage was found to be a major stage among seven stages of the dining experience process, with menu variety, and food presentation and display as the core of restaurant service. iv Factors influencing dining satisfaction during the actual meal experience were related to a unique cultural preference concept for Malay restaurants such as private dining space, food quality attribute of authenticity, eating style, restaurant decoration, waiting activities, prayer room, and traditional live band. Satisfaction influence factors for post-meal experience were self service payment, being bid farewell and being escorted to the exit door. Thirdly, this study because it adopted a qualitative research approach, managed to venture the role of Maslow’s Theory in customer satisfaction through the hierarchy of satisfaction of dining experience. The lowest level satisfaction was achieved when the basic needs of the customers’ dining at the restaurant was fulfilled or what restaurants provided to the customers was adequate or equal with customers’ expectation. A moderate level of satisfaction was achieved when customers could control their own dining activities. A high level of satisfaction resulted when the restaurants offered something above ordinary or which exceeded customers’ expectation. The highest level of satisfaction was achieved when the restaurants provided something that was outstanding and which surpassed the ordinary needs of the customers. Fourthly, the major way of managing factors influencing customer satisfaction dining experience was based on a systematic restaurant operation system. However, the key element that was responsible for the management of a systematic restaurant operation system depended on human resource management (the restaurant manager, front of house staff and kitchen staff), staff training and development, and restaurant rules. Fifthly, the analyses of customer satisfaction in a new socio-cultural context: Malaysian Malay restaurants provided an opportunity for a cross-comparison of ‘western’ and ‘eastern’ research findings and the identification of what was the same and what was different depending on the cultural context. Sixthly, the development of a conceptual framework had three major concepts: the input for the dining experience satisfaction (which consisted of factors influencing dining satisfaction and ways of managing it); the consumption of dining experience satisfaction at three phases: pre-meal, the actual meal and post-meal experience and the cognitive evaluation process of dining experience that led to satisfaction. And, lastly, the outcomes of dining experience satisfaction (in a form of pleasurable feelings and behavioural changes) which aided the understanding of customer satisfaction with the dining experience and ways managing it. This research suggested future research should consider additional factors to explain the overall satisfaction with the dining experience at Malaysian Malay restaurants (and /including) cross- type of restaurants and demographic profiles of customers; expand this research throughout the country to improve the transferability of the findings to other types of restaurant to assist restaurant managers in better matching the needs of each customer segment; extend the research to different ethnic restaurants that have different characteristics and attributes; undertake a comparative study of factors influencing customer satisfaction in Malay restaurants between two different groups of customers, such as Eastern versus Western; conduct a longitudinal study to compare changes in factors that influence customers’ satisfaction with dining experience at different times; and investigate whether the meal experience stage still plays the most important role in different types of restaurants
Lighting grid hierarchy for self-illuminating explosions
No full text
Rendering explosions with self-illumination is a challenging problem. Explosions contain animated volumetric light sources immersed in animated smoke that cast volumetric shadows, which play an essential role and are expensive to compute. We propose an efficient solution that redefines this problem as rendering with many animated lights by converting the volumetric lighting data into a large number of point lights. Focusing on temporal coherency to avoid flickering in animations, we introduce
lighting grid hierarchy
for approximating the volumetric illumination at different resolutions. Using this structure we can efficiently approximate the lighting at any point inside or outside of the explosion volume as a mixture of lighting contributions from all levels of the hierarchy. As a result, we are able to capture high-frequency details of local illumination, as well as the potentially strong impact of distant illumination. Most importantly, this hierarchical structure allows us to efficiently precompute volumetric shadows, which substantially accelerates the lighting computation. Finally, we provide a scalable approach for computing the multiple scattering of light within the smoke volume using our lighting grid hierarchy. Temporal coherency is achieved by relying on continuous formulations at all stages of the lighting approximation. We show that our method is efficient and effective approximating the self-illumination of explosions with visually indistinguishable results, as compared to path tracing. We also show that our method can be applied to other problems involving a large number of (animated) point lights.
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