30,813 research outputs found

    Interactive Vegetation Rendering with Slicing and Blending

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    Detailed and interactive 3D rendering of vegetation is one of the challenges of traditional polygon-oriented computer graphics, due to large geometric complexity even of simple plants. In this paper we introduce a simplified image-based rendering approach based solely on alpha-blended textured polygons. The simplification is based on the limitations of human perception of complex geometry. Our approach renders dozens of detailed trees in real-time with off-the-shelf hardware, while providing significantly improved image quality over existing real-time techniques. The method is based on using ordinary mesh-based rendering for the solid parts of a tree, its trunk and limbs. The sparse parts of a tree, its twigs and leaves, are instead represented with a set of slices, an image-based representation. A slice is a planar layer, represented with an ordinary alpha or color-keyed texture; a set of parallel slices is a slicing. Rendering from an arbitrary viewpoint in a 360 degree circle around the center of a tree is achieved by blending between the nearest two slicings. In our implementation, only 6 slicings with 5 slices each are sufficient to visualize a tree for a moving or stationary observer with the perceptually similar quality as the original model

    The Cyborg Astrobiologist: Testing a Novelty-Detection Algorithm on Two Mobile Exploration Systems at Rivas Vaciamadrid in Spain and at the Mars Desert Research Station in Utah

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    (ABRIDGED) In previous work, two platforms have been developed for testing computer-vision algorithms for robotic planetary exploration (McGuire et al. 2004b,2005; Bartolo et al. 2007). The wearable-computer platform has been tested at geological and astrobiological field sites in Spain (Rivas Vaciamadrid and Riba de Santiuste), and the phone-camera has been tested at a geological field site in Malta. In this work, we (i) apply a Hopfield neural-network algorithm for novelty detection based upon color, (ii) integrate a field-capable digital microscope on the wearable computer platform, (iii) test this novelty detection with the digital microscope at Rivas Vaciamadrid, (iv) develop a Bluetooth communication mode for the phone-camera platform, in order to allow access to a mobile processing computer at the field sites, and (v) test the novelty detection on the Bluetooth-enabled phone-camera connected to a netbook computer at the Mars Desert Research Station in Utah. This systems engineering and field testing have together allowed us to develop a real-time computer-vision system that is capable, for example, of identifying lichens as novel within a series of images acquired in semi-arid desert environments. We acquired sequences of images of geologic outcrops in Utah and Spain consisting of various rock types and colors to test this algorithm. The algorithm robustly recognized previously-observed units by their color, while requiring only a single image or a few images to learn colors as familiar, demonstrating its fast learning capability.Comment: 28 pages, 12 figures, accepted for publication in the International Journal of Astrobiolog

    Framework for the implementation of urban big screens in the public space

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    In the last decade, big urban screens have appeared in town squares and on building facades across the UK. The use of these screens brings new potentials and challenges for city regulators, artists, architects, urban designers, producers, broadcasters and advertisers. Dynamic moving images form new architectural material, affecting our perception and the experience of the space around us. A new form of urban space is emerging that is fundamentally different from what we have known, and it seems that we are ill-equipped to deal with and analyse it. We are just beginning to understand the opportunities for public information, art and community engagement. Most of screens at present serve mainly commercial purposes, they do not broadcast information aimed at sharing community content nor do they support public social interactions. We need to see more negotiation between commercial, public and cultural interests. The SCREAM project addresses these new challenges by looking at the physical urban spaces and the potential spaces created by the new technologies

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

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    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

    Design and creation of a virtual world of Petra, Jordan

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    Includes bibliographical references.This thesis presents the design and creation of a 3D virtual world of Petra, Jordan, based on the digital spatial documentation of this UNESCO World Heritage Site by the Zamani project. Creating digital records of the spatial domain of heritage sites is a well-established practice that employs the technologies of laser scanning, GPS and traditional surveys, aerial and close range photogrammetry, and 360-degree panorama photography to capture spatial data of a site. Processing this data to produce textured 3D models, sections elevations, GISs, and panorama tours to has led to the establishment of the field of virtual heritage. Applications to view this spatial data are considered too specialised to be used by the general public with only trained heritage practitioners being able to use the data. Additionally, data viewing platforms have not been designed to allow for the viewing of combinations of 3D data in an intuitive and engaging manner as currently each spatial data type must be viewed by independent software. Therefore a fully integrated software platform is needed which would allow any interested person, without prior training, easy access to a combination of spatial data, from anywhere in the world. This study seeks to provide a solution to the above requirement by using a game engine to assimilate spatial data of heritage sites in a 3D virtual environment where a virtual visitor is able to interactively engage with combinations of spatial data. The study first begins with an analysis of what virtual heritage applications, in the form of virtual environments, have been created, and the elements that were used in their creation. These elements are then applied to the design and creation of the virtual world of Petra
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