subdivide

Subdivide surface mesh

Since R2022b

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    Syntax

    subdivide(mesh,"midpoint-split",numIterations)
    subdivide(mesh,"loop",numIterations)

    Description

    subdivide(mesh,"midpoint-split",numIterations) subdivides the surface mesh mesh by using the midpoint-split method with the specified number of iterations. In this method, the function divides each face of the mesh into four faces in each iteration. New vertices lie at the midpoints of the edges of the original face.

    example

    subdivide(mesh,"loop",numIterations) subdivides the surface mesh by using a loop subdivision method with the specified number of iterations. In this methods, the function divides each triangular face into four by connecting the midpoints of the edges, then updates the new vertices as a weighted average of neighboring positions. The function divides each face into four faces in each iteration.

    example

    Examples

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    Open Live Script

    Define mesh vertices for a surface mesh.

    vertices = [1 -1  1; 1 1 1; -1 1 1; -1 -1 1; ...
            1 -1 -1; 1 1 -1; -1 1 -1; -1 -1 -1];

    Define the mesh faces using the vertices.

    faces = [6 2 1; 1 5 6; 8 4 3; 3 7 8; 6 7 3; 3 2 6; ...
         5 1 4; 4 8 5; 4 1 2; 2 3 4; 7 6 5; 5 8 7];

    Create and display the surface mesh.

    mesh = surfaceMesh(vertices,faces);
surfaceMeshShow(mesh)

    Subdivide the mesh using the midpoint-split method. Display the subdivided mesh.

    numIterations = 4;
subdivide(mesh,"midpoint-split",numIterations);
surfaceMeshShow(mesh,WireFrame=true)

    Open Live Script

    Read a surface mesh from a PLY file.

    fileName = fullfile(toolboxdir("lidar"),"lidardata", ...
           "surfaceMesh","sphere.ply");
mesh = readSurfaceMesh(fileName);

    Display the surface mesh.

    surfaceMeshShow(mesh,WireFrame=true)

    Subdivide the mesh using the loop method, and display the result.

    numIterations = 1;
subdivide(mesh,"loop",numIterations)
surfaceMeshShow(mesh,WireFrame=true)

    Input Arguments

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    Surface mesh, specified as a surfaceMesh object.

    Number of iterations for the subdivision method, specified as a positive integer. At each iteration, the function divides each face of the mesh into four faces.

    Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

    Limitations

    The function discards the FaceColors property of the input surfaceMesh object. The subdivided mesh does not have any face colors.

    References

    [1] Loop, Charles. “Smooth Subdivision Surfaces Based on Triangles.” Master's thesis. The University of Utah, 1987.

    Version History

    Introduced in R2022b

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    See Also

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