34
S. P. Donegan and M. A. Groeber
Table 1 Currently implemented SIMPL geometries, along with their topology and associated
data types
NAME
Topology Associated data
Description
Unknown
N/A
Any
The null geometry, used when the
underlying data have no spatial indices
Vertex
0
Vertex
A set of points, or point cloud
Edge
1
Edge/vertex
A set of edges, forming lines
Triangle
2
Face/edge/vertex
A set of triangles, forming a surface mesh
Quadrilateral 2
Face/edge/vertex
A set of quadrilaterals, forming a surface
mesh
Image
3
Cell
A structured rectilinear grid composed of
pixels/voxels of constant resolution
Rectgrid
3
Cell
An unstructured rectilinear grid,
composed of pixels/voxels of variable
resolution
Tetrahedral
3
Cell/face/edge/vertex A set of tetrahedra, forming a volume
mesh
Hexahedral
3
Cell/face/edge/vertex A set of hexahedra, forming a volume
mesh
Fig. 8 The inheritance hierarchy of SIMPL geometries. By providing abstract interfaces, represented in green, SIMPL allows for generic algorithm programming, reducing code replication
information, fast static access of the geometry, and the ability to store nonmanifold
simplices. However, shared element lists suffer from inefficient manipulations of
the geometry. For example, a shared element architecture is not suited toward mesh
refinement or decimation.