During the past thirty years, researchers have greatly sped up the naive ray tracing algorithm. However, the methods used to measure and compare their diverse algorithms have remained ad-hoc. This makes it difficult t...
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ISBN:
(纸本)9780982148945
During the past thirty years, researchers have greatly sped up the naive ray tracing algorithm. However, the methods used to measure and compare their diverse algorithms have remained ad-hoc. This makes it difficult to gauge the effectiveness of one author's approach versus that of another. Clarity, transparency and the reproducibility of experiments are foundational to proper science, therefore these discrepancies must be addressed. This paper will discuss a variety of sources from the literature to show the flaws in the current research paradigm. It will then propose a new method based on a benchmarking approach. Finally, the results of experimentation with the approach will be discussed and a conclusion will be drawn as to its applicability.
This article studies the suitability of different UHF radio propagation models for the European mobile TV standard DVB-H (Digital Video Broadcast - Handhelds). Accurate signal propagation modelling is key for DVB-H ne...
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ISBN:
(纸本)9788476534724
This article studies the suitability of different UHF radio propagation models for the European mobile TV standard DVB-H (Digital Video Broadcast - Handhelds). Accurate signal propagation modelling is key for DVB-H network planning in order to minimize deployment costs. This article analyzes three propagation models: Okumura-Hata, Xia-Bertoni, and a model based on the Hata formulae adding a diffraction term calculated using the Deygout method. The performance of the models is evaluated with measurement campaigns from several scenarios with different conditions such as transmitter height, environment, and available geographical data.
This paper presents a software tool, entitled ODQLab, to design dynamic quantizers for discrete-valued input control. ODQLab is a Matlab-based graphical tool, which enables us to obtain and verify dynamic quantizers w...
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ISBN:
(纸本)9781424453634
This paper presents a software tool, entitled ODQLab, to design dynamic quantizers for discrete-valued input control. ODQLab is a Matlab-based graphical tool, which enables us to obtain and verify dynamic quantizers without the knowledge of any sophisticated design theory. In this paper, we introduce the software tool with the underlying theory. The effectiveness is demonstrated by a design example and the experimental evaluation.
In Detail Every type of construction-such as building a house, a movie set, or a virtual set-needs a project. These projects are made of a lot of documents and technical drawings, which help in the construction of tho...
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ISBN:
(数字)9781849510493
ISBN:
(纸本)9781849510486
In Detail Every type of construction-such as building a house, a movie set, or a virtual set-needs a project. These projects are made of a lot of documents and technical drawings, which help in the construction of those buildings. These technical drawings and documents are just fine, but when you need to make a presentation of these projects for people who can't read technical drawings, things can get a little difficult. To make presentations for people who can't read technical drawings, we use tools like Blender. With Blender we can create, texture, and generate photo-real images of a project. These images are helpful to architects or companies to explain their projects in a better way. This book will show you how to generate real-looking architectural models quickly using Blender. You can also create natural scenery, landscapes, plants, various weather conditions, environmental factors, building materials such as wood, metal, brick, and more using Blender. As you walk through the chapters you will see that Blender is a tool, designed to give you high productivity and fast access to tools and menus helping you to create 3D models quickly for 3D visualization. You will learn how to add people to different scenes as well as other objects to an already existing photograph or a video making it easier to increase its realism. The process begins by learning how Blender user interface works then moves on and starts to deal with 3D modeling. In the 3D modeling chapters you will learn how to work with polygon-based modeling for architecture, creating walls and other architectural elements. But, a project is not only made of large scale models and this is the reason why you also learn to create 3D furniture. In the section about advanced lighting for architecture, you learn how to work with YafaRay to use global illumination techniques such as Photon Mapping and Path Tracing, and create photo-real renderings. In the last section of the book, dedicated to animation, we will c
Algorithms Design for pattern formation is an interesting science and many investigations are done about it. In this paper, a novel pattern formation method using asynchronous cellular automata for generating square K...
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ISBN:
(纸本)9783642159787
Algorithms Design for pattern formation is an interesting science and many investigations are done about it. In this paper, a novel pattern formation method using asynchronous cellular automata for generating square Kufic patterns is explored. Square Kufic is a kind of script that is used in many Islamic architecture buildings. In our new method, cellular automata rules causing a specified kind of pattern are manually extracted. The implementation results show this fact by using some special patterns in replicators.
A team of robots working to explore and map an area may need to share information about landmarks so as to register their local maps and to plan effective exploration strategies. In previous papers we have introduced ...
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ISBN:
(纸本)9781424466757
A team of robots working to explore and map an area may need to share information about landmarks so as to register their local maps and to plan effective exploration strategies. In previous papers we have introduced a combined image and spatial representation for landmarks: terrain spatiograms. We have shown that for manually selected views, terrain spatiograms provide an effective, shared representation for occlusion filtering and for combination of multiple views. In this paper, we present a landmark saliency architecture (LSA) that will automatically select candidate landmarks given some preference settings. Using a dataset of 21 outdoor stereo images generated by LSA, we show that the terrain spatiogram representation reliably recognizes automatically selected landmarks. The terrain spatiogram results are shown to improve on two purely appearance based approaches: template matching and image histogram matching.
Ever since it's introduction in 1980 the ray tracing algorithm has been a tricky puzzle. On the one hand it offers photo-realistic rendering superior to the more common rasterization algorithm, but on the other it...
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ISBN:
(纸本)9780982148945
Ever since it's introduction in 1980 the ray tracing algorithm has been a tricky puzzle. On the one hand it offers photo-realistic rendering superior to the more common rasterization algorithm, but on the other it's much too slow to serve as a replacement. Much of the rasterization algorithm's performance advantage lies in the use of special purpose hardware. This hardware, known as graphics cards, has evolved rapidly over the past decades, driven by demands for ever higher polygon counts. More recently, this pressure has lead to the introduction of programmable shader units to the graphics card architecture. These units became ever more programmable as researchers realized their potential as general parallel processing units. Eventually this trend lead to the exploration of the graphics card architecture as a ray tracing platform. This paper aims to explore the advent of this type of ray tracer and explain the developments that have been made in this field in order to see what the current state of the art is and where further research is required. It will also explore the defects that can be identified in the current literature and discuss how to address them.
This paper provides an overview of the application of computer graphics (CG) and 3D animation technologies in digital entertainment, in particular in film. With the emergence of 3D imaging era, CG technology is bringi...
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ISBN:
(纸本)9789077381540
This paper provides an overview of the application of computer graphics (CG) and 3D animation technologies in digital entertainment, in particular in film. With the emergence of 3D imaging era, CG technology is bringing and will continue to bring about great innovations to not only film and TV, but also game and digital entertainment industry in general.
This paper presents a novel 3D measurement system, which yields both depth and color information in real time, by calibrating a time-of-flight and two CCD cameras. The problem of occlusions is solved by the proposed f...
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ISBN:
(纸本)9781424466757
This paper presents a novel 3D measurement system, which yields both depth and color information in real time, by calibrating a time-of-flight and two CCD cameras. The problem of occlusions is solved by the proposed fast occluded-pixel detection algorithm. Since the system uses two CCD cameras, missing color information of occluded pixels is covered by one another. We also propose a robust object recognition using the 3D visual sensor. Multiple cues, such as color, texture and 3D (depth) information, are integrated in order to recognize various types of objects under varying lighting conditions. We have implemented the system on our autonomous robot and made the robot do recognition tasks (object learning, detection, and recognition) in various environments. The results revealed that the proposed recognition system provides far better performance than the previous system that is based only on color and texture information.
With a greater number of real-time graphics applications moving over to parametric surfaces from the polygonal domain, there is an inherent need to address various rendering bottlenecks that could hamper the move. Sca...
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ISBN:
(纸本)9783642172885
With a greater number of real-time graphics applications moving over to parametric surfaces from the polygonal domain, there is an inherent need to address various rendering bottlenecks that could hamper the move. Scaling the polygon count over various hardware platforms becomes an important factor. Much control is needed over the tessellation levels, either imposed by the hardware limitations or by the application. Developers like to create applications that run on various platforms without having to switch between polygonal and parametric versions to satisfy the limitations. In this paper, we present SD-2 (Semi-uniform, 2-Different), an adaptive tessellation algorithm for triangular parametric surfaces. The algorithm produces well distributed and semi-uniformly shaped triangles as a result of the tessellation. The SD-2 pattern requires new approaches for determining the edge tessellation factors, which can be fractional and change continuously depending on view parameters. The factors are then used to steer the tessellation of the parametric surface into a collection of triangle strips in a single pass. We compare the tessellation results in terms of GPU performance and surface quality by implementing SD-2 on PN patches.
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