Glossary

Acceleration Structure: A general term for ray tracing data structures that are used to accelerate ray tracing operations by partitioning geometric primitives (i.e. faces/elements) in a way that allows for efficient traversal and intersection testing.
BLAS: Bottom-Level Acceleration Structure. A lower-level acceleration structure, commonly a BVH, built over mesh primitives such as triangles. In a two-level ray tracing acceleration structure, BLAS instances are referenced by a TLAS.
BVH: Bounding Volume hierarchy
CAD: Computer-Aided Design
CAE: Computer-Aided Engineering
CSG: Constructive Solid Geometry
Coreform Cubit : A commercial software package for mesh generation, geometry simplification, and mesh-based simulations.
Cubit : A Sandia National Laboratory software package for mesh generation, geometry simplification, and mesh-based simulations.
DAGMC : Direct Accelerated Geometry Monte Carlo toolkit
Double-Down : A ray tracing extension for DAGMC that provides support for double-precision ray tracing on CAD-based geometries using Intel Embree.
DPRT : DeePeeRT (Double Precision Ray Tracing Toolkit) - A "Basics-only" Ray Tracing Library intended specifically for Double-Precision Ray Tracing being developed by NVIDIA.
Embree : A collection of high-performance CPU ray tracing kernels developed by Intel.
EntitySet: An arbitrary collection of entities in MOAB, including other EntitySet's. Parent-child relationships between EntitySet's can also be established. Synonymous with the term MeshSet.
FEA: Finite Element Analysis
GPRT : General Purpose Raytracing Toolkit - A vulkan based GPU accelerated ray tracing library capable of both GPU software and hardware accelerated ray tracing.
libMesh : A C++ finite element library that provides a framework for the development of parallel adaptive finite element methods.
MeshSet: A collection of entities in MOAB. Synonymous with EntitySet.
MOAB : Mesh-Oriented datABase
OpenMC : An open-source Monte Carlo code for neutron and photon transport.
RT hardware acceleration: The use of specialized hardware, such as dedicated ray tracing cores, avalaible on GPUs to signifciantly accelerate ray tracing operations. Such hardware can perform ray-triangle intersections and BVH traversal much faster than even GPU software implementations of ray tracing algorithms. However, they are limited to single precision support and often require vendor-specific APIs to target.
subdomain: A region of a mesh that is bounded by surfaces. In the context of XDG, a subdomain is a region of a mesh that is bounded by surfaces that are treated as interfaces between different materials. Also refferred to as a mesh block.
Tag: A named data field that can be associated with entities in MOAB. Each tag has an immutable data type. The size of the data can be fixed or variable.
TLAS: Top-Level Acceleration Structure. A higher-level acceleration structure built over one or more BLAS instances. A TLAS is used to cull larger groups of geometry before traversing the lower-level structures.
XDG: Accelerated Discretized Geometry