We propose a new routing graph, the restricted Delaunay graph (RDG), for mobile ad hoc networks. Combined with a node clustering algorithm, the RDG can be used as an underlying graph for geographic routing protocols. ...
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We propose a new routing graph, the restricted Delaunay graph (RDG), for mobile ad hoc networks. Combined with a node clustering algorithm, the RDG can be used as an underlying graph for geographic routing protocols. This graph has the following attractive properties: 1) it is planar;2) between any two graph nodes there exists a path whose length, whether measured in terms of topological or Euclidean distance, is only a constant times the minimum length possible;and 3) the graph can be maintained efficiently in a distributed manner when the nodes move around. Furthermore, each node only needs constant time to make routing decisions. We show by simulation that the RDG outperforms previously proposed routing graphs in the context of the Greedy perimeter stateless routing (GPSR) protocol. Finally, we investigate theoretical bounds on the quality of paths discovered using GPSR.
Water phenomena are some of the most visually spectacular effects found in nature. This paper presents an efficient hybrid method to model turbulent water such as fast flowing rivers and waterfalls with the intent tha...
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ISBN:
(纸本)1581138849
Water phenomena are some of the most visually spectacular effects found in nature. This paper presents an efficient hybrid method to model turbulent water such as fast flowing rivers and waterfalls with the intent that the model can be used as part of a larger environment or scene. The model presented uses hydrostatic theory to incorporate a 2D height field and a particle system to model respectively the main volume and spray of turbulent water. The user is able to submit any environment formed from spheres and panels making the solution very flexible and adaptable. A smooth representation of the water surface is obtained by fitting a uniform B-Spline surface to the height field. Foam, spray and other turbulent effects are represented by particles which are rendered as spheres or billboards. Our results show that the model provides a nearly realistic simulation of turbulent water and for simple scenes nearly interactive speeds are possible which compares favorably with alternative techniques. For non-interactive applications ray tracing can be used to obtain higher quality results.
The perception of a virtual environment depends on the user and the task the user is currently performing in that environment. Models of the human visual system can thus be exploited to significantly reduce computatio...
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ISBN:
(纸本)3898380580
The perception of a virtual environment depends on the user and the task the user is currently performing in that environment. Models of the human visual system can thus be exploited to significantly reduce computational time when rendering high fidelity images, without compromising the perceived visual quality. This paper considers how an image can be selectively rendered when a user is performing a visual task in an environment. In particular, we investigate to what level viewers fail to notice degradations in image quality, between nontask related areas and task related areas, when quality parameters such as image resolution, edge antialiasing and reflection and shadows are altered.
Our aim is to produce a tessellation of space into small voxels and, based on only a few tomographic projections of an object, assign to each voxel a label that indicates one of the components of interest constituting...
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The polymerization of paint changes the optical properties of a surface, such as scattering, absorption, and their phase angle dependence. Such changes can be recorded through relative albedo from a viewpoint of time ...
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In this paper we present the blue-c application programming interface, a software toolkit for media-rich, collaborative, immersive virtual reality applications. The blue-c API provides easy to use interfaces to all bl...
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ISBN:
(纸本)1581138849
In this paper we present the blue-c application programming interface, a software toolkit for media-rich, collaborative, immersive virtual reality applications. The blue-c API provides easy to use interfaces to all blue-c technology, including immersive projection, live 3D video acquisition and streaming, audio, tracking, and gesture recognition. The integration of multimedia data, including 2D video, 3D video, and animation, into the scene graph is presented. We emphasize on our performance-optimized 3D video handling and rendering pipeline, which is capable of rendering 3D video inlays consisting of up to 30,000 fragments updated at 10 Hz in real-time, enabling remote users to meet inside our virtual environment.
Triangulations in 2D and 3D are a necessary part of many applications. This paper brings a brief survey of main triangulations used in computergraphics and computational geometry, then focuses on Delaunay and greedy ...
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In this paper, we propose a new method, video repairing, to robustly infer missing static background and moving fore-ground due to severe damage or occlusion from a video. To recover background pixels, we extend the i...
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In this paper, we propose a new method, video repairing, to robustly infer missing static background and moving fore-ground due to severe damage or occlusion from a video. To recover background pixels, we extend the image repairing method, where layer segmentation and homography blending are used to preserve temporal coherence and avoid flickering. By exploiting the constraint imposed by periodic motion and a subclass of camera and object motions, we adopt a two-phase approach to repair moving foreground pixels: In the sampling phase, motion data are sampled and regularized by 3D tensor voting to maintain temporal coherence and motion periodicity. In the alignment phase, missing moving foreground pixels are inferred by spatial and temporal alignment of the sampled motion data at multiple scales. We experimented our system with some difficult examples, where the camera can be stationary or in motion.
In this paper, we present a system for reconstructing photorealistic 3D head models from multi-view images. In the proposed system, we perform two-pass bundle adjustments to reconstruct a photo-realistic 3D head model...
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This paper introduces feature-based textures, a new image representation that combines features and samples for high-quality texture mapping. Features identify boundaries within an image where samples change discontin...
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