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Mesh Geometry (mesh + geometry)

Distribution by Scientific Domains

Information Science and Computing	50%

Selected Abstracts

A-scalability and an integrated computational technology and framework for non-linear structural dynamics.

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 15 2003
Part 2: Implementation aspects, parallel performance results
Abstract An integrated framework and computational technology is described that addresses the issues to foster absolute scalability (A-scalability) of the entire transient duration of the simulations of implicit non-linear structural dynamics of large scale practical applications on a large number of parallel processors. Whereas the theoretical developments and parallel formulations were presented in Part 1, the implementation, validation and parallel performance assessments and results are presented here in Part 2 of the paper. Relatively simple numerical examples involving large deformation and elastic and elastoplastic non-linear dynamic behaviour are first presented via the proposed framework for demonstrating the comparative accuracy of methods in comparison to available experimental results and/or results available in the literature. For practical geometrically complex meshes, the A-scalability of non-linear implicit dynamic computations is then illustrated by employing scalable optimal dissipative zero-order displacement and velocity overshoot behaviour time operators which are a subset of the generalized framework in conjunction with numerically scalable spatial domain decomposition methods and scalable graph partitioning techniques. The constant run times of the entire simulation of ,fixed-memory-use-per-processor' scaling of complex finite element mesh geometries is demonstrated for large scale problems and large processor counts on at least 1024 processors. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Advanced techniques for interactive visualization of multi-resolution meshes,

COMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 5 2001
Markus Grabner
Abstract This paper addresses the problem of interactive visualization of multi-resolution triangle meshes. Visible switching between different levels of detail is avoided by smoothly interpolating mesh geometry between different levels. The interpolation parameter is derived from the screen-space geometric error of the affected mesh region instead of assigning a fixed time to the transition. The shortcomings of straightforward frame rate control mechanisms (i.e., overshooting and oscillation) are avoided by a semi-predictive algorithm. The average rendering time per triangle is measured and used to determine the desired number of faces. A set of experiments demonstrates the advantages of both methods. Copyright © 2002 John Wiley & Sons, Ltd. [source]

A System for View-Dependent Animation

COMPUTER GRAPHICS FORUM, Issue 3 2004
Parag Chaudhuri
In this paper, we present a novel system for facilitating the creation of stylized view-dependent 3D animation. Our system harnesses the skill and intuition of a traditionally trained animator by providing a convivial sketch based 2D to 3D interface. A base mesh model of the character can be modified to match closely to an input sketch, with minimal user interaction. To do this, we recover the best camera from the intended view direction in the sketch using robust computer vision techniques. This aligns the mesh model with the sketch. We then deform the 3D character in two stages - first we reconstruct the best matching skeletal pose from the sketch and then we deform the mesh geometry. We introduce techniques to incorporate deformations in the view-dependent setting. This allows us to set up view-dependent models for animation. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism - Animation 7 Figure 7. Our system takes as input a sketch (a), and a base mesh model (b), then recovers a camera to orient the base mesh (c), then reconstructs the skeleton pose (d), and finally deforms the mesh to find the best possible match with the sketch (e). [source]

Polygonal finite elements for topology optimization: A unifying paradigm

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 6 2010
Cameron Talischi
Abstract In topology optimization literature, the parameterization of design is commonly carried out on uniform grids consisting of Lagrangian-type finite elements (e.g. linear quads). These formulations, however, suffer from numerical anomalies such as checkerboard patterns and one-node connections, which has prompted extensive research on these topics. A problem less often noted is that the constrained geometry of these discretizations can cause bias in the orientation of members, leading to mesh-dependent sub-optimal designs. Thus, to address the geometric features of the spatial discretization, we examine the use of unstructured meshes in reducing the influence of mesh geometry on topology optimization solutions. More specifically, we consider polygonal meshes constructed from Voronoi tessellations, which in addition to possessing higher degree of geometric isotropy, allow for greater flexibility in discretizing complex domains without suffering from numerical instabilities. Copyright © 2009 John Wiley & Sons, Ltd. [source]