Cell Types
meshio++ uses its own canonical type names. Every format reader maps native element names to these; every writer maps them back.
Node ordering follows the VTK convention where available. See the meshio wiki for diagrams.
0-D
| Type | Nodes |
|---|---|
vertex | 1 |
1-D (line elements)
| Type | Nodes | Description |
|---|---|---|
line | 2 | Linear line |
line3 | 3 | Quadratic line |
line4 | 4 | Cubic line |
line5 | 5 | Quartic line |
line6 | 6 | |
line7 | 7 | |
line8 | 8 | |
line9 | 9 | |
line10 | 10 | |
line11 | 11 |
2-D surface elements
Triangles
| Type | Nodes |
|---|---|
triangle | 3 |
triangle6 | 6 |
triangle10 | 10 |
triangle15 | 15 |
triangle21 | 21 |
triangle28 | 28 |
triangle36 | 36 |
triangle45 | 45 |
triangle55 | 55 |
triangle66 | 66 |
Quadrilaterals
| Type | Nodes |
|---|---|
quad | 4 |
quad8 | 8 |
quad9 | 9 |
quad16 | 16 |
quad25 | 25 |
quad36 | 36 |
quad49 | 49 |
quad64 | 64 |
quad81 | 81 |
quad100 | 100 |
quad121 | 121 |
Arbitrary polygons
| Type | Nodes |
|---|---|
polygon | variable |
For polygon cells, all cells within a CellBlock must have the same number of nodes (the array shape determines this). Multiple CellBlock entries with type polygon but different node counts are permitted.
3-D volume elements
Tetrahedra
| Type | Nodes |
|---|---|
tetra | 4 |
tetra10 | 10 |
tetra20 | 20 |
tetra35 | 35 |
tetra56 | 56 |
tetra84 | 84 |
tetra120 | 120 |
tetra165 | 165 |
tetra220 | 220 |
tetra286 | 286 |
Hexahedra
| Type | Nodes |
|---|---|
hexahedron | 8 |
hexahedron20 | 20 |
hexahedron24 | 24 |
hexahedron27 | 27 |
hexahedron64 | 64 |
hexahedron125 | 125 |
hexahedron216 | 216 |
hexahedron343 | 343 |
hexahedron512 | 512 |
hexahedron729 | 729 |
hexahedron1000 | 1000 |
hexahedron1331 | 1331 |
Wedges (prisms)
| Type | Nodes |
|---|---|
wedge | 6 |
wedge15 | 15 |
wedge18 | 18 |
wedge40 | 40 |
wedge75 | 75 |
wedge126 | 126 |
wedge196 | 196 |
wedge288 | 288 |
wedge405 | 405 |
wedge550 | 550 |
Pyramids
| Type | Nodes |
|---|---|
pyramid | 5 |
pyramid13 | 13 |
pyramid14 | 14 |
Arbitrary polyhedra
| Type | Description |
|---|---|
polyhedron4 | Tetrahedron as polyhedron |
polyhedron5 | Pyramid as polyhedron |
polyhedronnN | N-faced polyhedron |
Polyhedron cells store their face connectivity as a list of lists (ragged), not a rectangular numpy array. The type name encodes the number of faces: polyhedron4 has 4 faces.
VTK Lagrange types
Higher-order VTK Lagrange elements (arbitrary polynomial order, controlled at runtime):
| Type |
|---|
VTK_LAGRANGE_CURVE |
VTK_LAGRANGE_TRIANGLE |
VTK_LAGRANGE_QUADRILATERAL |
VTK_LAGRANGE_TETRAHEDRON |
VTK_LAGRANGE_HEXAHEDRON |
VTK_LAGRANGE_WEDGE |
VTK_LAGRANGE_PYRAMID |
These are read and written by the VTK/VTU readers/writers only.