mesh.py

# -*- coding: utf-8 -*-
"""
Created on Sun Feb 14 15:43:44 2010.

@author: - B. Burle & A. Gramfort
"""

import numpy as np
import openmeeg as om


class Mesh():
    """
    A class allowing to open meshes.

    A class allowing to open meshes data (vertices and triangles), and plot.
    their respective surfaces.

    Example:
    --------
    head = Mesh("MyHeadFile.tri")

    To plot the surface of the corresponding object, call the function
    'self.plot(**kwarg)'. The kwarg options are the one from
    mayavi.mlab.triangular_mesh
    """

    def __init__(self, fname=None):
        """Give a filename."""
        self.points = []
        self.faces = []
        if fname is not None:
            self.load(fname)

    def load(self, fname):
        """Load a filename."""
        m = om.Mesh(fname)
        self.points = np.zeros((m.nb_vertices(), 3), dtype=float)
        self.faces = np.zeros((m.nb_triangles(), 3), dtype=int)
        vit = m.vertex_begin()
        iit = 0
        while vit != m.vertex_end():
            self.points[iit, :] = [vit.value()(0),
                                   vit.value()(1),
                                   vit.value()(2)]
            iit += 1
            vit.incr()
        tit = m.begin()
        iit = 0
        while tit != m.end():
            self.faces[iit, :] = [tit.value().s1().getindex(),
                                  tit.value().s2().getindex(),
                                  tit.value().s3().getindex()]
            iit += 1
            tit.incr()

    def plot(self, **kwarg):
        """Plot mesh with Mayavi."""
        from mayavi import mlab
        f = mlab.triangular_mesh(self.points[:, 0], self.points[:, 1],
                                 self.points[:, 2], self.faces, **kwarg)
        return f