Estimating performance of an ray- tracing ASIC design

Journal ArticleRecursive ray tracing is a powerful rendering technique used to compute realistic images by simulating the global light transport in a scene. Algorithmic improvements and FPGA-based hardware implementations of ray tracing have demonstrated realtime performance but hardware that achieves performance levels comparable to commodity rasterization graphics chips is still not available. This paper describes the architecture and ASIC implementations of the DRPU design (Dynamic Ray Processing Unit) that closes this performance gap. The DRPU supports fully programmable shading and most kinds of dynamic scenes and thus provides similar capabilities as current GPUs. It achieves high efficiency due to SIMD processing of floating point vectors, massive multithreading, synchronous execution of packets of threads, and careful management of caches for scene data. To support dynamic scenes B-KD trees are used as spatial index structures that are processed by a custom traversal and intersection unit and modified by an Update Processor on scene changes

Developing serious games for cultural heritage: a state-of-the-art review

Although the widespread use of gaming for leisure purposes has been well documented, the use of games to support cultural heritage purposes, such as historical teaching and learning, or for enhancing museum visits, has been less well considered. The state-of-the-art in serious game technology is identical to that of the state-of-the-art in entertainment games technology. As a result, the field of serious heritage games concerns itself with recent advances in computer games, real-time computer graphics, virtual and augmented reality and artificial intelligence. On the other hand, the main strengths of serious gaming applications may be generalised as being in the areas of communication, visual expression of information, collaboration mechanisms, interactivity and entertainment. In this report, we will focus on the state-of-the-art with respect to the theories, methods and technologies used in serious heritage games. We provide an overview of existing literature of relevance to the domain, discuss the strengths and weaknesses of the described methods and point out unsolved problems and challenges. In addition, several case studies illustrating the application of methods and technologies used in cultural heritage are presented

Serious Games in Cultural Heritage

Although the widespread use of gaming for leisure purposes has been well documented, the use of games to support cultural heritage purposes, such as historical teaching and learning, or for enhancing museum visits, has been less well considered. The state-of-the-art in serious game technology is identical to that of the state-of-the-art in entertainment games technology. As a result the field of serious heritage games concerns itself with recent advances in computer games, real-time computer graphics, virtual and augmented reality and artificial intelligence. On the other hand, the main strengths of serious gaming applications may be generalised as being in the areas of communication, visual expression of information, collaboration mechanisms, interactivity and entertainment. In this report, we will focus on the state-of-the-art with respect to the theories, methods and technologies used in serious heritage games. We provide an overview of existing literature of relevance to the domain, discuss the strengths and weaknesses of the described methods and point out unsolved problems and challenges. In addition, several case studies illustrating the application of methods and technologies used in cultural heritage are presented

Construction and Evaluation of an Ultra Low Latency Frameless Renderer for VR.

© 2016 IEEE.Latency-the delay between a users action and the response to this action-is known to be detrimental to virtual reality. Latency is typically considered to be a discrete value characterising a delay, constant in time and space-but this characterisation is incomplete. Latency changes across the display during scan-out, and how it does so is dependent on the rendering approach used. In this study, we present an ultra-low latency real-time ray-casting renderer for virtual reality, implemented on an FPGA. Our renderer has a latency of 1 ms from tracker to pixel. Its frameless nature means that the region of the display with the lowest latency immediately follows the scan-beam. This is in contrast to frame-based systems such as those using typical GPUs, for which the latency increases as scan-out proceeds. Using a series of high and low speed videos of our system in use, we confirm its latency of 1 ms. We examine how the renderer performs when driving a traditional sequential scan-out display on a readily available HMO, the Oculus Rift OK2. We contrast this with an equivalent apparatus built using a GPU. Using captured human head motion and a set of image quality measures, we assess the ability of these systems to faithfully recreate the stimuli of an ideal virtual reality system-one with a zero latency tracker, renderer and display running at 1 kHz. Finally, we examine the results of these quality measures, and how each rendering approach is affected by velocity of movement and display persistence. We find that our system, with a lower average latency, can more faithfully draw what the ideal virtual reality system would. Further, we find that with low display persistence, the sensitivity to velocity of both systems is lowered, but that it is much lower for ours

Fast Reliable Ray-tracing of Procedurally Defined Implicit Surfaces Using Revised Affine Arithmetic

Fast and reliable rendering of implicit surfaces is an important area in the field of implicit modelling. Direct rendering, namely ray-tracing, is shown to be a suitable technique for obtaining good-quality visualisations of implicit surfaces. We present a technique for reliable ray-tracing of arbitrary procedurally defined implicit surfaces by using a modification of Affine Arithmetic called Revised Affine Arithmetic. A wide range of procedurally defined implicit objects can be rendered using this technique including polynomial surfaces, constructive solids, pseudo-random objects, procedurally defined microstructures, and others. We compare our technique with other reliable techniques based on Interval and Affine Arithmetic to show that our technique provides the fastest, while still reliable, ray-surface intersections and ray-tracing. We also suggest possible modifications for the GPU implementation of this technique for real-time rendering of relatively simple implicit models and for near real-time for complex implicit models

Energy-Efficient Interactive Ray Tracing of Static Scenes on Programmable Mobile GPUs

Mobile technology is improving in quality and capability faster now than ever before. When first introduced, cell phones were strictly used to make voice calls; now, they play satellite radio, MP3s, streaming television, have GPS and navigation capabilities, and have multi-megapixel video cameras. In the near future, cell phones will have programmable graphics processing units (GPU) that will allow users to play games similar to those currently available for top-of-the-line game consoles. Personal digital assistants enable users with full email, scheduling, and internet browsing capabilities in addition to those features offered on cell phones. Underlying all this mobile technology and entertainment is a battery whose technology has just barely tripled in the past 15 years, compared to available disk capacity that has increased over 1,000-fold. Ray tracing is a rendering technique used to generate photorealistic images that include reflections, refraction, participating media, and can fairly easily be extended to include photon mapping for indirect illumination and caustics. In recent years, ray tracing has been implemented on the GPU using various acceleration structures to facilitate rendering. Until now, all studies have used build time and achievable frame rates to determine which acceleration structure is best for ray tracing. We present the very first results comparing both CPU and GPU raytracing using various acceleration structures in terms of energy consumption. By exploring per-pixel costs, we provide insight on the energy consumption and frame rates that can be experienced on cell phones and other mobile devices based on currently available screen resolutions. Our results show that the choice in processing unit has the greatest affect on energy and time costs of ray tracing, followed by the size of the viewport used, and the choice of acceleration structure has the least impact on efficiency. For mobile devices enabled with a programmable GPU, whether it is a cell phone, PDA, or laptop computer, a bounding volume hierarchy implemented on the GPU is the most energy-efficient acceleration structure for ray tracing. Ray tracing on cellular phones with smaller screen resolutions is most energy-efficient using a CPU-based Kd-Tree implementation