MeshReader

Read properties of mesh

Since R2023b

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    Description

    The MeshReader object stores the properties of the mesh such as the points, triangles, and tetrahedra in the mesh, edge lengths of the triangles, growth rate, and mesh quality. You can use this information to fine tune the mesh for your application. You can also visualize the mesh of the metal region, dielectric region, or the entire antenna or array structure and detect bad features in the mesh.

    Creation

    You can create the MeshReader object using the mesh function. There are two ways to create this object:

    • Run any port, surface, or field analysis on the antenna or array to automatically generate the mesh. Then use m = mesh(object) syntax to create the MeshReader object.

    • Manually mesh the antenna or array by setting MaxEdgeLength property of the mesh to create the MeshReader object. For example, m = mesh(object,MaxEdgeLength=0.01) creates a MeshReader object.

    Properties

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    This property is read-only.

    Cartesian coordinates of points in mesh, returned as a 3-by-N matrix double. N represents the number of points and each column of the matrix represents x, y, and z-coordinates of the points.

    Example: [-0.0188 -1e-3 0; -0.0375 -0.0188 0]'

    Data Types: double

    This property is read-only.

    Mesh triangles connectivity list, specified as a 4-by-N integer matrix, where N is the number of triangles in the mesh. First three rows of each column in Triangles contains the vertex IDs that define a triangle. The vertex IDs are the column numbers of the Points property. The ID of a triangle in the mesh is the corresponding column number in the Triangles property.

    Example: [96 97 146 1;...;1 293 294 2]'

    Data Types: double

    This property is read-only.

    Mesh tetrahedra connectivity list, specified as a 4-by-N integer matrix, where N is the number of tetrahedra in the mesh. Each column of Tetrahedra contains the vertex IDs that define a tetrahedron. The vertex IDs are the column numbers of the Points property. The ID of a tetrahedron in the mesh is the corresponding column number in the Tetrahedra property. This property has an empty value for the antennas without a dielectric substrate.

    Example: [96 97 146 438;...;12 547 305 304]'

    Data Types: double

    This property is read-only.

    Maximum edge length of mesh triangles, returned as a positive scalar in meters.

    Example: 0.01

    Data Types: double

    This property is read-only.

    Minimum edge length of mesh triangles, returned as a positive scalar in meters.

    Example: 2e-3

    Data Types: double

    This property is read-only.

    Gradation in the triangle sizes of the mesh, returned as a scalar in the range (0,1).

    Example: GrowthRate=0.7 states that the growth rate of the mesh is 70 percent.

    Data Types: double

    This property is read-only.

    Mesh quality is a measure of degree of structural similarity of the mesh triangles to an equilateral triangle. MinimumMeshQuality is the lowest observed mesh quality out of all the mesh triangles, returned as a scalar in the range (0,1). A minimum mesh quality of 1 means all the mesh triangles are equilateral.

    Example: MinimumMeshQuality=0.72 states that the lowest quality triangle in the mesh is 72 percent similar to an equilateral triangle.

    Data Types: double

    This property is read-only.

    Mode of mesh creation, returned as either "auto" or "manual". The MeshMode is "auto" when the mesh gets created due to running any analysis function on the antenna or array. The MeshMode is "manual" when the mesh is created by specifying the MaxEdgeLength value in the mesh function run on an antenna, array, or custom geometry.

    Example: MeshMode="manual"

    Data Types: string

    Object Functions

    showDielectricSurfaceMeshDisplay dielectric surface mesh of antenna or array
    showDielectricVolumeMeshDisplay dielectric volume mesh of antenna or array
    showMeshAllDisplay complete metal-dielectric mesh of antenna or array
    showMetalMeshDisplay metal mesh of antenna or array
    showDuplicateVerticesHighlight duplicate vertices in STL file or mesh
    showFreeTrianglesHighlight free triangles in STL file or mesh
    showNonManifoldEdgesHighlight non-manifold edges in STL file or mesh
    showNonManifoldVerticesHighlight non-manifold vertices in STL file or mesh
    showNormalTransitionEdgesHighlight normal transition edges in STL file or mesh
    showSliversHighlight slivers in STL file or mesh
    showTVerticesHighlight T-vertices in STL file or mesh

    Examples

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    Open Live Script

    This example shows how to read mesh parameters of a microstrip patch antenna and view the metal, dielectric, and complete mesh.

    Create Microstrip Patch Antenna

    Create a microstrip patch antenna with copper conductor and FR4 PCB substrate. Run impedance analysis on this antenna at 1.67 GHz to automatically generate the mesh. 

    p = patchMicrostrip(Conductor=metal("Copper"), Substrate=dielectric("FR4"));
figure
impedance(p,1.67e9);

    Figure contains an axes object. The axes object with title Impedance, xlabel Frequency (GHz), ylabel Impedance (ohms) contains 2 objects of type line. One or more of the lines displays its values using only markers These objects represent Resistance, Reactance.

    Read Mesh Parameters of Antenna

    Read the mesh parameters such as number of points, triangles, and tetrahedra, maximum and minimum edge length, mesh growth rate, and quality using the MeshReader object.

    m = mesh(p)
    m = 
  MeshReader with properties:

                Points: [3×1644 double]
             Triangles: [4×2013 double]
            Tetrahedra: [4×4617 double]
         MaxEdgeLength: 0.0044
         MinEdgeLength: 2.2012e-04
            GrowthRate: 0.9500
    MinimumMeshQuality: 0.0289
              MeshMode: 'auto'

    View Mesh of Antenna

    View the metal mesh.

    figure
showMetalMesh(m)

    Figure contains an axes object. The axes object with title Metal mesh, xlabel x (m), ylabel y (m) contains an object of type patch. This object represents PEC.

    View the dielectric surface mesh.

    figure
showDielectricSurfaceMesh(m)

    Figure contains an axes object. The axes object with title Dielectric surface, xlabel x (m), ylabel y (m) contains an object of type patch.

    View the dielectric volume mesh.

    figure
showDielectricVolumeMesh(m)

    Figure contains an axes object. The axes object with title Dielectric volume, xlabel x (m), ylabel y (m) contains an object of type patch.

    View the overall mesh.

    figure
showMeshAll(m)

    Figure contains an axes object. The axes object with title Metal-Dielectric, xlabel x (m), ylabel y (m) contains 2 objects of type patch. This object represents PEC.

    Tips

    The MeshReader object stores the triangulation information of the mesh in the form of points and triangles connectivity list. This allows stlFileChecker functions to be directly used on the MeshReader object to detect and display bad features of the mesh. For example, below code shows the detection and display of T-Vertices in the mesh of a microstrip patch antenna operating at 1.67 GHz.

    ant = patchMicrostrip(Conductor=metal("Copper"),... 
           Substrate=dielectric("FR4"));
impedance(ant,1.67e9);
m = mesh(ant)
detectTVertices(m);
m.TVertices
showTVertices(m)

    Alternatively, you can write the mesh data to a STL file using stlwrite function and then run stlFileChecker on that STL file to detect bad features of the mesh. For example, below code shows the detection of all the bad features in the mesh by converting the mesh data to a STL file using stlwrite function and running stlFileChecker on that data. Once all the bad features are detected, you can choose individual feature to be highlighted on the mesh plot using functions of the stlFileChecker object.

    ant = patchMicrostrip(Conductor=metal("Copper"),...
              Substrate=dielectric("FR4"));
impedance(ant,1.67e9);
m = mesh(ant)
tr = triangulation(m.Triangles(1:3,:)',...
          m.Points(:,1:max(unique(m.Triangles(1:3,:)))')');
stlwrite(tr,"sampleFile.stl");
stlFileChecker("sampleFile.stl")

    Version History

    Introduced in R2023b

    See Also

    Functions

    Objects

    Topics