How to Guide
How to create simple meshes
We will generate the tetrahedral mesh inside a rectangular block. The block will have the dimensions shown below:
a, b, c = 2.0, 2.5, 3.0The tetrahedra will be generated in a regular pattern, with the number of edges per side of the block given as
na, nb, nc = 2, 2, 3Now we bring in function to generate mesh, and use it to generate the incidence relation representing the mesh.
using MeshSteward: T4block
conn = T4block(a, b, c, na, nb, nc);The variable conn is an incidence relation. This will become the base relation of the mesh. The mesh is first created.
using MeshSteward: Mesh
m = Mesh()Then the $(3, 0)$ incidence relation, which defines the tetrahedral elements in terms of the vertices at their corners, is attached to it.
using MeshSteward: attach!
attach!(m, conn);We can now inspect the mesh by printing its summary.
println(summary(m))How to find a particular incidence relation
Find an incidence relation based on a code. The $(3, 0)$ incidence relation, which defines the tetrahedral elements in terms of the vertices at their corners, is found like this:
conn = increl(m, (3, 0))We can extract the boundary of this incidence relation and attach it to the mesh:
using MeshCore: ir_boundary
bconn = ir_boundary(conn)This incidence relation than may be attached to the mesh, with a name and a code.
attach!(m, bconn, "boundary_triangles") To recover this incidence relation from the mesh we can do:
bconn = increl(m, ((2, 0), "boundary_triangles"))How to visualize meshes
The mesh can be exported for visualization. The tetrahedral elements are the base incidence relation of the mesh.
using MeshSteward: baseincrel
using MeshSteward: vtkwrite
vtkwrite("trunc_cyl_shell_0-elements", baseincrel(mesh))Start "Paraview", load the file "trunc_cyl_shell_0-elements.vtu" and select for instance view as "Surface with Edges". The result will be a view of the surface of the tetrahedral mesh.
@async run(`paraview trunc_cyl_shell_0-elements.vtu`)