meshlabxml/transform.py
def vert_function(script, x_func='x', y_func='y', z_func='z', selected=False):
    """Geometric function using muparser lib to generate new Coordinates

    You can change x, y, z for every vertex according to the function specified.

    See help(mlx.muparser_ref) for muparser reference documentation.
    It's possible to use the following per-vertex variables in the expression:

    Variables (per vertex):
        x, y, z (coordinates)
        nx, ny, nz (normal)
        r, g, b, a (color)
        q (quality)
        rad (radius)
        vi (vertex index)
        vtu, vtv (texture coordinates)
        ti (texture index)
        vsel (is the vertex selected? 1 yes, 0 no)
        and all custom vertex attributes already defined by user.

    Args:
        x_func (str): function to generate new coordinates for x
        y_func (str): function to generate new coordinates for y
        z_func (str): function to generate new coordinates for z
        selected (bool): if True, only affects selected vertices (ML ver 2016.12 & up)

    Layer stack:
        No impacts

    MeshLab versions:
        2016.12
        1.3.4BETA
    """
    if script.ml_version == '1.3.4BETA':
        filter_xml = ''.join([
            '  <filter name="Geometric Function">\n',
            '    <Param name="x" ',
            'value="{}" '.format(str(x_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func x = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="y" ',
            'value="{}" '.format(str(y_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func y = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="z" ',
            'value="{}" '.format(str(z_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func z = " ',
            'type="RichString" ',
            '/>\n',
            '  </filter>\n'])
    else:
        filter_xml = ''.join([
            '  <filter name="Per Vertex Geometric Function">\n',
            '    <Param name="x" ',
            'value="{}" '.format(str(x_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func x = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="y" ',
            'value="{}" '.format(str(y_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func y = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="z" ',
            'value="{}" '.format(str(z_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func z = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="onselected" ',
            'value="%s" ' % str(selected).lower(),
            'description="only on selection" ',
            'type="RichBool" ',
            '/>\n',
            '  </filter>\n'])
    util.write_filter(script, filter_xml)
    return None
def vert_function(script, x_func='x', y_func='y', z_func='z', selected=False):
    """Geometric function using muparser lib to generate new Coordinates

    You can change x, y, z for every vertex according to the function specified.

    See help(mlx.muparser_ref) for muparser reference documentation.
    It's possible to use the following per-vertex variables in the expression:

    Variables (per vertex):
        x, y, z (coordinates)
        nx, ny, nz (normal)
        r, g, b, a (color)
        q (quality)
        rad (radius)
        vi (vertex index)
        vtu, vtv (texture coordinates)
        ti (texture index)
        vsel (is the vertex selected? 1 yes, 0 no)
        and all custom vertex attributes already defined by user.

    Args:
        x_func (str): function to generate new coordinates for x
        y_func (str): function to generate new coordinates for y
        z_func (str): function to generate new coordinates for z
        selected (bool): if True, only affects selected vertices (ML ver 2016.12 & up)

    Layer stack:
        No impacts

    MeshLab versions:
        2016.12
        1.3.4BETA
    """
    if script.ml_version == '1.3.4BETA':
        filter_xml = ''.join([
            '  <filter name="Geometric Function">\n',
            '    <Param name="x" ',
            'value="{}" '.format(str(x_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func x = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="y" ',
            'value="{}" '.format(str(y_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func y = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="z" ',
            'value="{}" '.format(str(z_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func z = " ',
            'type="RichString" ',
            '/>\n',
            '  </filter>\n'])
    else:
        filter_xml = ''.join([
            '  <filter name="Per Vertex Geometric Function">\n',
            '    <Param name="x" ',
            'value="{}" '.format(str(x_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func x = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="y" ',
            'value="{}" '.format(str(y_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func y = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="z" ',
            'value="{}" '.format(str(z_func).replace('&', '&amp;').replace('<', '&lt;')),
            'description="func z = " ',
            'type="RichString" ',
            '/>\n',
            '    <Param name="onselected" ',
            'value="%s" ' % str(selected).lower(),
            'description="only on selection" ',
            'type="RichBool" ',
            '/>\n',
            '  </filter>\n'])
    util.write_filter(script, filter_xml)
    return None
Geometric function using muparser lib to generate new Coordinates

    You can change x, y, z for every vertex according to the function specified.

    See help(mlx.muparser_ref) for muparser reference documentation.
    It's possible to use the following per-vertex variables in the expression:

    Variables (per vertex):
        x, y, z (coordinates)
        nx, ny, nz (normal)
        r, g, b, a (color)
        q (quality)
        rad (radius)
        vi (vertex index)
        vtu, vtv (texture coordinates)
        ti (texture index)
        vsel (is the vertex selected? 1 yes, 0 no)
        and all custom vertex attributes already defined by user.

    Args:
        x_func (str): function to generate new coordinates for x
        y_func (str): function to generate new coordinates for y
        z_func (str): function to generate new coordinates for z
        selected (bool): if True, only affects selected vertices (ML ver 2016.12 & up)

    Layer stack:
        No impacts

    MeshLab versions:
        2016.12
        1.3.4BETA