Geometry from Triangulated Mesh

3-D Geometry from a Finite Element Mesh

This example shows how to import a 3-D mesh into a PDE model. Importing a mesh creates the corresponding geometry in the model.

The tetmesh file that ships with your software contains a 3-D mesh. Load the data into your Workspace.

load tetmesh

Examine the node and element sizes.

size(tet)
ans = 1×2

        4969           4

size(X)
ans = 1×2

        1456           3

The data is transposed from the required form as described in geometryFromMesh.

Create data matrices of the appropriate sizes.

nodes = X';
elements = tet';

Create a PDE model and import the mesh.

model = createpde();
geometryFromMesh(model,nodes,elements);

The model contains the imported mesh.

model.Mesh
ans = 
  FEMesh with properties:

             Nodes: [3x1456 double]
          Elements: [4x4969 double]
    MaxElementSize: 8.2971
    MinElementSize: 1.9044
     MeshGradation: []
    GeometricOrder: 'linear'

View the geometry and face numbers.

pdegplot(model,'FaceLabels','on','FaceAlpha',0.5)

2-D Multidomain Geometry

Create a 2-D multidomain geometry from a mesh.

Load information about nodes, elements, and element-to-domain correspondence into your workspace. The file MultidomainMesh2D ships with your software.

load MultidomainMesh2D

Create a PDE model.

model = createpde;

Import the mesh into the model.

geometryFromMesh(model,nodes,elements,ElementIdToRegionId);

View the geometry and face numbers.

pdegplot(model,'FaceLabels','on')