We present an automatic camera placement method for generating image-based models from scenes with known geometry. Our method first approximately determines the set of surfaces visible from a given viewing area and th...
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We present an automatic camera placement method for generating image-based models from scenes with known geometry. Our method first approximately determines the set of surfaces visible from a given viewing area and then selects a small set of appropriate camera positions to sample the scene from. We define a quality measure for a surface as seen, or covered, from the given viewing area. Along with each camera a position, we store the set of surfaces which are best covered by this camera. Next, one reference view is generated from each camera position by rendering the scene. Pixels in each reference view that do not belong to the selected set of polygons are masked out. The image-based model generated by our method, covers every visible surface only once, associating it with a camera position from which it is covered with quality that exceeds a user-specified quality threshold. The result is a compact non-redundant image-based model with controlled quality. The problem of covering every visible surface with a minimum number of cameras (guards) can be regarded as an extension to the well-known Art Gallery Problem. However, since the 3D polygonal model is textured, the camera-polygon visibility relation is not binary;instead, it has a weight - the quality of the polygon's coverage.
We present a system to combine arbitrary triangle mesh animations with physically based Finite Element Method (FEM) simulation, enabling control over the combination both in space and time. The input is a triangle mes...
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We present a system to combine arbitrary triangle mesh animations with physically based Finite Element Method (FEM) simulation, enabling control over the combination both in space and time. The input is a triangle mesh animation obtained using any method, such as keyframed animation, character rigging, 3D scanning, or geometric shape modeling. The input may be non-physical, crude or even incomplete. The user provides weights, specified using a minimal user interface, for how much physically based simulation should be allowed to modify the animation in any region of the model, and in time. Our system then computes a physically-based animation that is constrained to the input animation to the amount prescribed by these weights. This permits smoothly turning physics on and off over space and time, making it possible for the output to strictly follow the input, to evolve purely based on physically based simulation, and anything in between. Achieving such results requires a careful combination of several system components. We propose and analyze these components, including proper automatic creation of simulation meshes (even for non-manifold and self-colliding undeformed triangle meshes), converting triangle mesh animations into animations of the simulation mesh, and resolving collisions and self-collisions while following the input.
This paper presents a new technique called motion balance filtering, which corrects an unbalanced motion to a balanced one while preserving the original motion characteristics as much as possible. Differently from pre...
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This paper presents a new technique called motion balance filtering, which corrects an unbalanced motion to a balanced one while preserving the original motion characteristics as much as possible. Differently from previous approaches that deal only with the balance of static posture, we solve the problem of balancing a dynamic motion. We achieve dynamic balance by analyzing and controlling the trajectory of the zero moment point (ZMP). Our algorithm consists of three steps. First, it analyzes the ZMP trajectory to find out the duration in which dynamic balance is violated. Dynamic imbalance is identified by the ZMP trajectory segments lying out of the supporting area. Next, the algorithm modifies the ZMP trajectory by projecting it into the supporting area. Finally, it generates the balanced motion that satisfies the new ZMP constraint. This process is formulated as a constrained optimization problem so that the new motion resembles the original motion as much as possible. Experiments prove that our motion balance filtering algorithm is a useful method to add physical realism to a kinematically edited motion.
The grid density requirements generally vary from problem to problem, hence interactive control over grid generation is required. While multi-block grids can be used to control the grid density globally, interactive m...
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The grid density requirements generally vary from problem to problem, hence interactive control over grid generation is required. While multi-block grids can be used to control the grid density globally, interactive mechanisms are required to carry out grid density manipulations locally. If we are able to accommodate an unequal number of grid points on opposite edges in a block, then this can be achieved with minimum manipulations in the neighbouring blocks. This also results in savings on the number of grid points. In this paper an algorithm for this is presented. A mechanism to control distribution of boundary points and the orientation of grid lines within a block, using simple algebraic expressions is also presented.
Focuses on the commercial usage of panoramic computer graphic images. Modification of illumination by image relighting; Effect of relighting techniques on light fine tuning; Application of an interactive Panorama View...
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Focuses on the commercial usage of panoramic computer graphic images. Modification of illumination by image relighting; Effect of relighting techniques on light fine tuning; Application of an interactive Panorama Viewer software in image feasibility demonstration; Use of a hardware graphics accelerator for real-time image magnification.
An enhanced differential chain coding (EDCC) scheme is developed for transmission of high-quality line graphics. Experiments showed that, compared to DCC with a resolution of the enhanced graphics adapter (EGA: 640x35...
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An enhanced differential chain coding (EDCC) scheme is developed for transmission of high-quality line graphics. Experiments showed that, compared to DCC with a resolution of the enhanced graphics adapter (EGA: 640x350pixels), EDCC with a resolution of 2100x1536 pixels gives a much higher quality with a modest extension in storage and transmission capacity.
The papers in this special section includes extended versions of four of the best papers presented at the 2012 ACM SIGGRAPH Symposium on Interactive 3D graphics and Games held from 9-11 March 2012 in Costa Mesa, Calif...
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The papers in this special section includes extended versions of four of the best papers presented at the 2012 ACM SIGGRAPH Symposium on Interactive 3D graphics and Games held from 9-11 March 2012 in Costa Mesa, California.
The nucleotides crucial for the specific aminoacylation of yeast tRNA(Asp) by its cognate synthetase have been identified. Steady-state aminoacylation kinetics of unmodified tRNA transcripts indicate that G34, U35, C3...
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The nucleotides crucial for the specific aminoacylation of yeast tRNA(Asp) by its cognate synthetase have been identified. Steady-state aminoacylation kinetics of unmodified tRNA transcripts indicate that G34, U35, C36, and G73 are important determinants of tRNA(Asp) identity. Mutations at these positions result in a large decrease (19- to 530-fold) of the kinetic specificity constant (ratio of the catalytic rate constant k(cat) and the Michaelis constant K(m)) for aspartylation relative to wild-type tRNA(Asp). Mutation to G10-C25 within the D-stem reduced k(cat)/K(m) eightfold. This fifth mutation probably indirectly affects the presentation of the highly conserved G10 nucleotide to the synthetase. A yeast tRNA(Phe) was converted into an efficient substrate for aspartyl-tRNA synthetase through introduction of the five identity elements. The identity nucleotides are located in regions of tight interaction between tRNA and synthetase as shown in the crystal structure of the complex and suggest sites of base-specific contacts.
Region-display spatializations represent documents metaphorically as points within regions. Semantic interrelatedness is expressed by some combination of interpoint distance and region membership. In two experiments, ...
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Region-display spatializations represent documents metaphorically as points within regions. Semantic interrelatedness is expressed by some combination of interpoint distance and region membership. In two experiments, the authors investigate judgments of document similarity as a function of these variables. Distance matters, but region membership largely determines judged similarity;hue further modifies it.
作者：
OSLAND, CDGraphics Section
Central Computing Division Rutherford Appleton Laboratory Chilton DIDCOT Oxon OX11 0QX England
Two documents have achieved the status of full International Standards for graphics — GKS (Graphical Kernel System) and CGM (computer graphics Metafile). GKS is a procedural definition of the user interface to a grap...
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Two documents have achieved the status of full International Standards for graphics — GKS (Graphical Kernel System) and CGM (computer graphics Metafile). GKS is a procedural definition of the user interface to a graphic system; CGM is the specification for a graphics file format. This paper describes the salient features of GKS and CGM and sets them in historical context and in relationship to the other standards being developed. It describes and explains the functions and features of the two standards.
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