15 results
Search Results
Now showing 1 - 10 of 15
Item 3D Posture Reconstruction and Human Animation from 2D Feature Points(The Eurographics Association and Blackwell Publishing Ltd., 2005) Zhao, Jianhui; Li, Ling; Chee Keong, KwohAn optimal approach is proposed in this paper for posture reconstruction and human animation from 2D feature points extracted from the monocular images containing human motions. Biomechanical constraints are encoded in every joint of the adopted 3D skeletal human model to make sure that each state of the joints represents a physically valid posture. Size of the human model is adjusted to be consistent with the human figure represented by feature points. Energy Function is defined to represent the residuals between the extracted 2D feature points and the corresponding features resulted from projection of the 3D human model. Local Adjustment and Global Adjustment procedures are proposed to place the joints and body segments into proper locations and orientations in 3D space to create the posture with the minimum value of Energy Function. To find the optimal solution of the ill-posed recovery problem from 2D to 3D, Genetic Algorithm is employed in the high-dimensional parameter space by considering all the parameters simultaneously. Smooth and continuous changes between consecutive frames are considered in development of the human animation procedure. The proposed approach produces optimal reconstruction results of any possible human postures and movements. It is different from classical kinematics and dynamics formulations, and is an attempt to bridge the gap between computer vision and computer animation in human motion study.Item Practical CFD Simulations on Programmable Graphics Hardware using SMAC(The Eurographics Association and Blackwell Publishing Ltd., 2005) Scheidegger, Carlos E.; Comba, Joao L. D.; Da Cunha, Rudnei D.The explosive growth in integration technology and the parallel nature of rasterization-based graphics APIs (Application Programming Interface) changed the panorama of consumer-level graphics: today, GPUs (Graphics Processing Units) are cheap, fast and ubiquitous. We show how to harness the computational power of GPUs and solve the incompressible Navier-Stokes fluid equations significantly faster (more than one order of magnitude in average) than on CPU solvers of comparable cost. While past approaches typically used Stam s implicit solver, we use a variation of SMAC (Simplified Marker and Cell). SMAC is widely used in engineering applications, where experimental reproducibility is essential. Thus, we show that the GPU is a viable and affordable processor for scientific applications. Our solver works with general rectangular domains (possibly with obstacles), implements a variety of boundary conditions and incorporates energy transport through the traditional Boussinesq approximation. Finally, we discuss the implications of our solver in light of future GPU features, and possible extensions such as three-dimensional domains and free-boundary problems.Item Editorial(The Eurographics Association and Blackwell Publishing Ltd., 2005) Duke, David; Scopigno, RobertoItem 26th EUROGRAPHICS General Assembly(The Eurographics Association and Blackwell Publishing Ltd., 2005)Item Algorithms for Interactive Editing of Level Set Models(The Eurographics Association and Blackwell Publishing Ltd., 2005) Museth, Ken; Breen, David E.; Whitaker, Ross T.; Mauch, Sean; Johnson, DavidLevel set models combine a low-level volumetric representation, the mathematics of deformable implicit surfaces and powerful, robust numerical techniques to produce a novel approach to shape design. While these models offer many benefits, their large-scale representation and numerical requirements create significant challenges when developing an interactive system. This paper describes the collection of techniques and algorithms (some new, some pre-existing) needed to overcome these challenges and to create an interactive editing system for this new type of geometric model. We summarize the algorithms for producing level set input models and, more importantly, for localizing/minimizing computation during the editing process. These algorithms include distance calculations, scan conversion, closest point determination, fast marching methods, bounding box creation, fast and incremental mesh extraction, numerical integration and narrow band techniques. Together these algorithms provide the capabilities required for interactive editing of level set models.Item Siggraph 2005 Los Angeles, California, 31st July-4th August 2005(The Eurographics Association and Blackwell Publishing Ltd., 2005) Laycock, S.D.; Laycock, R.G.; Day, A.M.Item New EUROGRAPHICS Fellows(The Eurographics Association and Blackwell Publishing Ltd., 2005)Item A Family of Inexpensive Sampling Schemes(The Eurographics Association and Blackwell Publishing Ltd., 2005) Hasselgren, Jon; Akenine-Moeller, Tomas; Laine, SamuliTo improve image quality in computer graphics, antialiazing techniques such as supersampling and multisampling are used. We explore a family of inexpensive sampling schemes that cost as little as 1.25 samples per pixel and up to 2.0 samples per pixel. By placing sample points in the corners or on the edges of the pixels, sharing can occur between pixels, and this makes it possible to create inexpensive sampling schemes. Using an evaluation and optimization framework, we present optimized sampling patterns costing 1.25, 1.5, 1.75 and 2.0 samples per pixel.Item Author Index Volume 24 (2005)(The Eurographics Association and Blackwell Publishing Ltd., 2005)Item REPORT OF THE STATUTORY AUDITORS TO THE GENERAL MEETING OF THE MEMBERS OF EUROGRAPHICS ASSOCIATION GENEVA(The Eurographics Association and Blackwell Publishing Ltd., 2005)