Mesh Scripting

    From FreeCAD Documentation


    To get access to the Mesh module you have to import it first:

    import Mesh


    To create an empty mesh object just use the standard constructor:

    mesh = Mesh.Mesh()

    You can also create an object from a file:

    mesh = Mesh.Mesh("D:/temp/Something.stl")

    Or create it out of a set of triangles described by their corner points:

    triangles = [
    # triangle 1
    [-0.5000, -0.5000, 0.0000], [0.5000, 0.5000, 0.0000], [-0.5000, 0.5000, 0.0000],
    #triangle 2
    [-0.5000, -0.5000, 0.0000], [0.5000, -0.5000, 0.0000], [0.5000, 0.5000, 0.0000],
    meshObject = Mesh.Mesh(triangles)

    The Mesh-Kernel takes care of creating a topologically correct data structure by sorting coincident points and edges.



    To create regular geometries you can use one of the create*() methods. A torus, for instance, can be created as follows:

    m = Mesh.createTorus(8.0, 2.0, 50)

    The first two parameters define the radii of the torus and the third parameter is a sub-sampling factor for how many triangles are created. The higher this value the smoother the mesh.

    The Mesh module also provides three Boolean methods: union(), intersection() and difference():

    m1, m2              # are the input mesh objects
    m3 = Mesh.Mesh(m1)  # create a copy of m1
    m3.unite(m2)        # union of m1 and m2, the result is stored in m3
    m4 = Mesh.Mesh(m1)
    m4.intersect(m2)    # intersection of m1 and m2
    m5 = Mesh.Mesh(m1)
    m5.difference(m2)   # the difference of m1 and m2
    m6 = Mesh.Mesh(m2)
    m6.difference(m1)   # the difference of m2 and m1, usually the result is different to m5

    Here is an example that creates a pipe using the difference() method:

    import FreeCAD, Mesh
    cylA = Mesh.createCylinder(2.0, 10.0, True, 1.0, 36)
    cylB = Mesh.createCylinder(1.0, 12.0, True, 1.0, 36)
    cylB.Placement.Base = (FreeCAD.Vector(-1, 0, 0)) # move cylB to avoid co-planar faces
    pipe = cylA
    pipe = pipe.difference(cylB)
    pipe.flipNormals() # somehow required
    doc = FreeCAD.ActiveDocument
    obj = d.addObject("Mesh::Feature", "Pipe")
    obj.Mesh = pipe



    An extensive, though hard to use, source of mesh related scripting are the unit test scripts of the Mesh module. In these unit tests literally all methods are called and all properties/attributes are tweaked. So if you are bold enough, take a look at the Unit Test module.

    See also: Mesh API.