View-dependent simplification using parallel half edge collapses

Highly detailed models are a requirement for many applications in computer graphics. The necessary level of detail, however, may vary depending on the application. To provide a tradeoff, mesh simplification is used to generate approximations of a model which can be used to reduce processing time. We present a parallel approach to triangle mesh simplification that is designed to allow fast, view-dependent simplification of manifold triangle meshes. Our approach performs a vertex analysis on every vertex of a given triangle mesh and selects a set of vertices for removal. Vertex removal is executed using the parallel half edge collapse. Based on the half edge collapse that replaces an edge with one of its endpoints, we have devised a set of boundaries that enable parallel application of half edge collapses even on neighbouring vertices. Since the mesh topology may not allow removal of all vertices marked for removal in one step, we apply multiple iterations of the parallel half edge collapse, reevaluating remaining vertices marked for removal for further improvement of results

View-dependent triangle mesh simplification using GPU-accelerated vertex removal

We present an approach to view-dependent triangle mesh simplification based on vertex removal, which focuses on allowing the execution of a large number of operations in parallel. The individual vertex removal operations are designed to be applied without any need for communication or synchronisation between operations, thus allowing an efficient implementation on modern GPUs to reduce the computation time for the coarse mesh. Since we cannot compute the entire simplification in a single step and have to perform several iterations of parallel vertex removal, we aim to maximize the number of vertices removed from the mesh in each iteration to efficiently use the available hardware and reduce the number of necessary iterations. The removal operation is based on the half edge collapse and avoids mesh foldovers and topological inconsistencies at each step

Parallel Grid Adaptation and Dynamic Load Balancing for a CFD Solver

In this paper we present the parallel version of a CFD solver which works on unstructured 3-dimensional grids. The parallelization was achieved using the MPI library. The program includes a method for dynamically adapting a grid on a parallel computer. Grid adaptation is one of the reasons that lead to a poor workload distribution. Therefore a dynamic load balancing method was implemented in order to make sure that the available hardware is utilized in an efficient way. The paper concludes with the presentation of a performance test.JRC.F.4-Nuclear design safet

Dynamic Load Balancing in Parallel Numerical Simulations of Reactive Gas Flows

Balancing the workload distribution in a parallel environment is an important measure to reduce the total runtime of a parallel program. Since load balancing involves a significant amount of inter-processor communication the main problem is to keep this overhead as low as possible while at the same time trying to keep the workload as evenly distributed as possible. This task is particularly difficult in multi-phase calculations like in the simulation of reactive gas flows. In this paper we present a balancing strategy which reduces the problem of multple phases to a single phase problem by reordering calculations within the timestep loop.JRC.F.4-Nuclear design safet

DRIHM (2US): An e-Science environment for hydro-meteorological research on high impact weather events

From 1970 to 2012, about 9,000 high-impact weather events were reported globally, causing the loss of 1.94 million lives and damage of $2.4 trillion (U.S. dollars). The scientific community is called to action to improve the predictive ability of such events and communicate forecasts and associated risks both to affected populations and to those making decisions. At the heart of this challenge lies the ability to have easy access to hydrometeorological data and models and to facilitate the necessary collaboration between meteorologists, hydrologists, and computer science experts to achieve accelerated scientific advances. Two European Union (EU)-funded projects, Distributed Research Infrastructure for Hydro-Meteorology (DRIHM) and DRIHM to United States of America (DRIHM2US), sought to help address this challenge by developing a prototype e-science environment providing advanced end-to-end services (models, datasets, and postprocessing tools), with the aim of paving the way to a step change in how scientists can approach studying these events, with a special focus on flood events in complex topographic areas. This paper describes the motivation and philosophy behind this prototype e-science environment together with certain key components, focusing on hydrometeorological aspects that are then illustrated through actionable research for a critical flash flood event that occurred in October 2014 in Liguria, Italy

DRIHM (2US): An e-Science environment for hydro-meteorological research on high impact weather events

From 1970 to 2012, about 9,000 high-impact weather events were reported globally, causing the loss of 1.94 million lives and damage of $2.4 trillion (U.S. dollars). The scientific community is called to action to improve the predictive ability of such events and communicate forecasts and associated risks both to affected populations and to those making decisions. At the heart of this challenge lies the ability to have easy access to hydrometeorological data and models and to facilitate the necessary collaboration between meteorologists, hydrologists, and computer science experts to achieve accelerated scientific advances. Two European Union (EU)-funded projects, Distributed Research Infrastructure for Hydro-Meteorology (DRIHM) and DRIHM to United States of America (DRIHM2US), sought to help address this challenge by developing a prototype e-science environment providing advanced end-to-end services (models, datasets, and postprocessing tools), with the aim of paving the way to a step change in how scientists can approach studying these events, with a special focus on flood events in complex topographic areas. This paper describes the motivation and philosophy behind this prototype e-science environment together with certain key components, focusing on hydrometeorological aspects that are then illustrated through actionable research for a critical flash flood event that occurred in October 2014 in Liguria, Italy