2.3.5. Mesh Types

PoIndexedMesh3D PoIndexedMesh3D PoIndexedMesh3D or PbIndexedMesh3D PbIndexedMesh3D PbIndexedMesh3D This mesh represents any 3D volume shape composed of a list of cells. The mesh can be convex or not, and can be connected or not. Each cell is a polyhedron which can either be a tetrahedron (4 nodes), a pyramid (5 nodes), a pentahedron (6 nodes), or a hexahedron (8 nodes). The mesh is said to be indexed because each cell is defined by its node indices pointing to an array of node coordinates. Two adjacent cells must have three or four common node indices. If a cell’s facet belongs to only one cell, this facet is considered to be a part of an external or internal mesh limit (an internal mesh limit is the limit of an inside hole). The cell’s facets that do not belong to the mesh limit must be referenced exactly twice in the mesh. A cell can only have one adjacent cell along one facet or no adjacent cell at all.

The cells must be numbered as shown: The following rule is applied: for each cell, the first three or four indices (depending on the cell type) define a cell’s facet, and orient this facet towards the interior side of the element. The topology of the mesh is defined by the number of cells numElems, the number of nodes numNodes, the node indices list of each cells elemIndex, and the number of nodes of each cell elemType. elemType is an array of numElems integers. For example, elemType [i] = 8 means that the i-th cell is a hexahedron. elemIndex is an array of N integers where N = elemType [0]+ elemType [1]+...+ elemType [ numElems -1].


PoTetrahedronMesh3D PoTetrahedronMesh3D PoTetrahedronMesh3D or PbTetrahedronMesh3D PbTetrahedronMesh3D PbTetrahedronMesh3D This mesh represents any 3D volume shape composed of a list of tetrahedrons. The mesh can be convex or not, and can be connected or not. Each tetrahedron is defined by four nodes whose indices point to an array of nodes coordinates. Two adjacent tetrahedrons must have three common node indices. If a tetrahedron’s facet belongs to only one tetrahedron, this facet is considered to be a part of an external or internal mesh limit. The tetrahedron’s facet which do not belong to the mesh limit must be referenced exactly twice in the mesh. A tetrahedron can only have one adjacent tetrahedron along one facet or no adjacent tetrahedron at all.

Each tetrahedron must be numbered as shown:

The following rule is applied: for each tetrahedron, the first three indices define a facet, and orient this facet towards the interior side of the tetrahedron.

The topology of the mesh is defined by the number of tetrahedrons numTetrahedrons, the number of nodes numNodes, and the four node indices of each tetrahedron tetrahedronIndex. tetrahedronIndex is an array of numTetrahedrons *4 integers, where tetrahedronIndex [i*4 + j] is the j-th node of the i-th tetrahedron (0<=j<4).


PoHexahedronMesh3D PoHexahedronMesh3D PoHexahedronMesh3D or PbHexahedronMesh3D PbHexahedronMesh3D PbHexahedronMesh3D This mesh represents any 3D volume shape composed of a list of hexahedrons. The mesh can be convex or not, and can be connected or not. Each hexahedron is defined by its eight nodes whose indices point to an array of nodes coordinates. Two adjacent hexahedrons must have four common node indices. If a hexahedron’s facet belongs to only one hexahedron, this facet is considered to be a part of an external or internal mesh limit. The hexahedron’s facets which do not belong to the mesh limit must be referenced exactly twice in the mesh. A hexahedron can only have one adjacent hexahedron along one facet or no adjacent hexahedron at all.

Each hexahedron must be numbered as shown:

The following rule is applied: for each hexahedron, the first four indices define a facet, and orient this facet towards the interior side of the hexahedron.

The topology of the mesh is defined by the number of hexahedrons numHexahedrons, the number of nodes numNodes, and the eight node indices of each hexahedron hexahedronIndex. hexahedronIndex is an array of numHexahedrons *8 integers, where hexahedronIndex [i*8 + j] is the j-th node of the i-th hexahedron (0<=j<8).