SIGMA

"Computational physics solvers take a continuous domain of interest, the problem geometry, and apply specialized discretizations based on the Partial Differential Equation (PDE) describing the relevant physical model. The discretization involves two components: computing a discrete mesh of the domain that accurately models the continuous geometry and defining the solution fields as degrees-of-freedom on the mesh, that needs to be computed by appropriately solving the discretized operators. The resulting single/multi component physics solutions need to be serialized back to a format amenable for visualization.

SIGMA provides interfaces and tools to access geometry data, create high quality unstructured meshes along with unified data-structures to load and manipulate parallel computational meshes for various applications to enable efficient physics solver implementations. Mesh generation is a complex problem since most problem geometries involve complicated curved surfaces that require physics imposed spatial resolution and optimized elements for good quality. These tools simplify the process of generation and handling of discrete meshes with scalable algorithms to leverage efficient usage from desktop to petascale architectures."

The components of SIGMA are:

CGM — The Common Geometry Module (CGM), is a set of libraries for querying and modifying CAD and other types of geometry data; CGM provides a common API and topological model for accessing geometry represented in ACIS, Open.CASCADE, and a variety of other solid modeling engines. CGM provides the geometry infrastructure for the CUBIT mesh generation toolkit.CGM implements the ITAPS iGeom interface.

MOAB — The Mesh-Oriented datABase, or MOAB, is a library for representing unstructured and structured mesh, and field data on a mesh. MOAB represents the finite element zoo, plus polygons and polyhedra. MOAB’s data model is simple yet powerful, being able to represent most kinds of metadata often accompanying the mesh (e.g. boundary conditions, processor partitions, geometric topology).

MeshKit — Library of advanced mesh-generation algorithms. An open-source library of mesh generation tools and algorithms. This library is designed with two uses in mind: first, for those wanting an open-source mesh generation library, and second, for those implementing new meshing algorithms.

http://sigma.mcs.anl.gov/

https://cubit.sandia.gov/