Method fromData

python/pymesh/misc/quaternion.py:43–76

Create the rotation to rotate v1 to v2 Args: v1 (``numpy.ndarray``): From vector. Normalization not necessary. v2 (``numpy.ndarray``): To vector. Normalization not necessary. Returns: The following values are returned. * ``quat`` (:

(cls, v1, v2)

    @classmethod
    def fromData(cls, v1, v2):
        """ Create the rotation to rotate v1 to v2

        Args:
            v1 (``numpy.ndarray``): From vector. Normalization not necessary.
            v2 (``numpy.ndarray``): To vector. Normalization not necessary.

        Returns:
            The following values are returned.

            * ``quat`` (:class:`Quaternion`): Corresponding quaternion that
              rotates ``v1`` to ``v2``.
        """
        eps = 1e-12
        v1 /= norm(v1)
        v2 /= norm(v2)
        c = np.dot(v1, v2)
        if c < -1.0 + eps:
            # v1 is parallel and opposite of v2
            u,s,v = svd(np.array([v1, v2]))
            axis = v[2,:]
        else:
            axis = np.cross(v1, v2)
            l = norm(axis)
            if l > 0.0:
                axis /= norm(axis)
            else:
                # Parallel vectors.
                axis = v1

        w_sq = 0.5 * (1.0 + c)
        l = sqrt(1.0 - w_sq) * axis
        quat = np.array([sqrt(w_sq), l[0], l[1], l[2]])
        return cls(quat)

    def norm(self):
        """ Quaternion norm.