This paper introduces the Auto Terrain Generation System (ATGS), which is based on an Interactive Genetic Algorithm (IGA) that enables non-specialist users to rapidly generate terrains. The motivation for using an IGA...
详细信息
ISBN:
(纸本)9781424481262
This paper introduces the Auto Terrain Generation System (ATGS), which is based on an Interactive Genetic Algorithm (IGA) that enables non-specialist users to rapidly generate terrains. The motivation for using an IGA is discussed, existing terrain generation techniques are described and a new approach, based on a fractal terrain engine, is outlined. graphics engines allow terrains to be specified with over 800 floating point parameters, which can overwhelm non-specialist users. These parameters also create a vast search space for auto-terrain generation systems that can complicate procedural techniques. ATGS addresses these issues via interaction with the user, which is implemented in ATGS by a web based user interface that allows users to rapidly indicate terrain preferences. These user preferences are used by a genetic algorithm to explore a multi-dimensional parameter space that satisfies the user's intuition and aesthetics. Proof of concept experiments are outlined, results are presented and future research work is projected.
This paper investigates the problem of geo-localization in GPS challenged urban canyons using only skylines. Our proposed solution takes a sequence of upward facing omnidirectional images and coarse 3D models of citie...
详细信息
ISBN:
(纸本)9781424466757
This paper investigates the problem of geo-localization in GPS challenged urban canyons using only skylines. Our proposed solution takes a sequence of upward facing omnidirectional images and coarse 3D models of cities to compute the geo-trajectory. The camera is oriented upwards to capture images of the immediate skyline, which is generally unique and serves as a fingerprint for a specific location in a city. Our goal is to estimate global position by matching skylines extracted from omni-directional images to skyline segments from coarse 3D city models. Under day-time and clear sky conditions, we propose a sky-segmentation algorithm using graph cuts for estimating the geo-location. In cases where the skyline gets affected by partial fog, night-time and occlusions from trees, we propose a shortest path algorithm that computes the location without prior sky detection. We show compelling experimental results for hundreds of images taken in New York, Boston and Tokyo under various weather and lighting conditions (daytime, foggy dawn and night-time).
The applications of virtual and augmented reality require high performance equipment normally associated with high costs, inaccessible for small organizations and educational institutions. By adding computing power an...
详细信息
ISBN:
(纸本)9789048191505
The applications of virtual and augmented reality require high performance equipment normally associated with high costs, inaccessible for small organizations and educational institutions. By adding computing power and storage capacity of several PCs interconnected by a network we have an alternative of high performance and low cost. The objective of this project is to implement an augmented reality platform integrated with items available in the laboratories of an educational institution, such as PCs, webcams, Ethernet networking and free software. This platform is an attractive and economical alternative for the development and implementation of virtual and augmented reality applications to enable low-budget institutions simulate processes, physical phenomena, weather, etc. In this first phase, we have a prototype that creates a scene consisting of a set of virtual objects, the video stream acquired from a Webcam and processes the captured image into a graphic with a set of virtual objects. A user facing the angle of acquisition of the webcam can interact with virtual objects in the scene with only the move of his hand. Although our prototype is reduced to only two computers the first in which images are acquired through the webcam and the second where the mixture, processing and visualization of the scene is made, these early results demonstrate the feasibility of our idea and are a strong motivation for continuing the project. As future work we have planned to increase the number of Webcams, to explore the interaction with complex virtual scenes as well as distributing the processing of the scene among a group of computers to increase the size of the scene displayed.
We introduce a new representation for modeling and rendering plants and trees. The representation is multiresolution and can be automatically generated and rendered in an efficient way. For the trunk and branches we p...
详细信息
We introduce a new representation for modeling and rendering plants and trees. The representation is multiresolution and can be automatically generated and rendered in an efficient way. For the trunk and branches we procedurally build a multiresolution structure that preserves the visual appearance of a tree, when rendered at different levels of detail. For the leaves we build a hierarchy of images by pre-processing the botanical tree structure. Unlike other representations, the visual quality of our representation does not depend on viewing position and direction. Our models can be applied to any computer graphics area that requires modeling outdoor scenes like interactive walkthroughs and fly-by's, realistic rendering, simulation and computer games. (C) 2010 Published by Elsevier Ltd.
Fast instance generation is a key requirement in atlas-based registration and other problems that need a large number of atlas instances. This paper describes a new method to represent and construct intensity atlases....
详细信息
ISBN:
(纸本)9781424441242
Fast instance generation is a key requirement in atlas-based registration and other problems that need a large number of atlas instances. This paper describes a new method to represent and construct intensity atlases. Both geometry and intensity information are represented using B-spline deformation lattices;intensities are approximated using the multi-level B-spline approximation algorithm during model creation and the parallel computation capability of modern graphics processing units is used to accelerate the process of instance generation. Experiments with distal radius CTs show that, with a coefficients-to-voxels ratio of 0.16, intensities can be approximated up to an average accuracy of 2 +/- 17 grey-levels (out of 3072 total grey-levels), and instances of resolution 256 x 256 x 200 can be produced in a rate of 25 instances per second with a GeForce GTX 285 video card, which is about 500 times performance improvement over the traditional method that uses plain CPU.
We study the watermarking of 2D vector data and introduce a framework which preserves topological properties of the input. Our framework is based on so-called maximum perturbation regions (MPR) of the input vertices, ...
详细信息
ISBN:
(纸本)9781424474936
We study the watermarking of 2D vector data and introduce a framework which preserves topological properties of the input. Our framework is based on so-called maximum perturbation regions (MPR) of the input vertices, which is a concept similar to the just-noticeable-difference constraint. The MPRs are computed by means of the Voronoi diagram of the input and allow us to avoid (self-)intersections of input objects that might result from the embedding of the watermark. We demonstrate and analyze the applicability of this new framework by coupling it with a well-known approach to watermarking that is based on Fourier descriptors. However, our framework is general enough such that any robust scheme for the watermarking of vector data can be applied.
Most modeling and simulation approaches applied in cell biology assume a homogeneous distribution of particles in space, although experimental studies reveal the importance of space to understand the dynamics of cells...
详细信息
ISBN:
(纸本)9781424498642
Most modeling and simulation approaches applied in cell biology assume a homogeneous distribution of particles in space, although experimental studies reveal the importance of space to understand the dynamics of cells. There are already numerous spatial approaches focusing on the simulation of cells. Recently, they have been complemented by a set of spatial modeling languages whose operational semantics are tied partly to existing simulation algorithms. These modeling languages allow an explicit description of spatial phenomena, and facilitate analysis of the temporal spatial dynamics of cells by a clear separation between model, semantics, and simulator. With the supported level of abstraction, each of those offers a different perception of the spatial phenomena under study. In this paper, we give an overview of existing modeling formalisms and discuss some ways of combining approaches to tackle the problem the computational costs induced by spatial dynamics.
Background/Context: New technologies have been largely absent in arts education curriculum even though they offer opportunities to address arts integration, equity, and the technological prerequisites of an increasing...
详细信息
Background/Context: New technologies have been largely absent in arts education curriculum even though they offer opportunities to address arts integration, equity, and the technological prerequisites of an increasingly digital age. This paper draws upon the emerging professional field of "media arts" and the ways in which youth use new technologies for communication to design a 21st-century K-12 arts education curriculum. Description of prior research on the subject and/or its intellectual context and/or policy context: Building on sociocultural theories of constructionism as well as Dewey's theories of the arts and aesthetics as a democratic pedagogy, this study draws upon over three years of extensive field study at a digital design studio where underprivileged youth accessed programming environments emphasizing graphics, music, and video. Purpose/Objective/Research Question/Focus of the Study: This study documents what youth learn through media art making in informal settings, the strengths and limitations of capitalizing on youth culture in media art production, and the distinct contributions that media arts education can make to the classroom environment. Research Design: A mixed-methods approach was utilized that analyzed data from participants and professional interviews, an archive of youths' media art, and videotape documentation of youth at work on their projects. Conclusions/Recommendations: Findings point to the ways in which youth engage with technology that encourages active learning and how new types of software can be used to illustrate and encourage this process.
Non-photorealistic rendering has been attracting attention in the field of computer graphics. A common approach to artistic rendering is using a shape model which utilizes mesh data. In recent years, the use of point ...
详细信息
ISBN:
(纸本)9788086943879
Non-photorealistic rendering has been attracting attention in the field of computer graphics. A common approach to artistic rendering is using a shape model which utilizes mesh data. In recent years, the use of point clouds as shape models has increased due to the rapid development of 3D-scanners used to create them. Correspondingly, there has been an increase in the research on point clouds. We propose a stipple rendering method as a type of artistic rendering for point clouds, based on a hybrid image/object space. First, we eliminate hidden points based on an image space. Next, we apply a novel shading method to the visible points based on an image space. Lastly, we apply the above two results to the input point cloud. We implement the proposed method using a graphics processing unit to accomplish the interactive rendering. The experimental results show that we can achieve shading and shadowing interactively.
This paper introduces a methodology for constructing pen and ink style landscape illustrations using B-spline surface models. After a brief discussion of the history of 19th and 20th century manual techniques and rece...
详细信息
This paper introduces a methodology for constructing pen and ink style landscape illustrations using B-spline surface models. After a brief discussion of the history of 19th and 20th century manual techniques and recent developments in automated non-photorealistic rendering (NPR) techniques, the paper discusses polynomial models for surface rendering and their implementation in the OpenGL graphics interface. The paper then discusses the generation of silhouettes and form lines for topographic surfaces from a set of triangulated vertices obtained from polygonal tessellations. An implementation of the methodology outlined in the paper is described and tested. The results are analyzed and suggestions for further research are presented.
暂无评论