'Find rotation to fit head shapes.'

def fit_hsp_points(self):

    src_pts = (self.hsp.points - self.hsp.nasion)
    tgt_pts = (self.processed_mri_points - self.mri.nasion)
    tgt_pts *= self.scale
    tgt_pts -= [self.trans_x, self.trans_y, self.trans_z]
    x0 = (self.rot_x, self.rot_y, self.rot_z)
    rot = fit_point_cloud(src_pts, tgt_pts, rotate=True, translate=False, x0=x0)
    (self.rot_x, self.rot_y, self.rot_z) = rot
