   // a random matrix into a set of lookAt vectors.
    for (var i = 0; i < tmp.length; i++)
      tmp[i] = Math.random();
    var eyeExp = [0, 0, 0];
    var fwdExp = [0, 0, 0];
    var upExp = [0, 0, 0];
    var centerExp = [0, 0, 0];
    // Project the random matrix into a real modelview matrix.
    goog.vec.Matrix4.toLookAt(tmp, eyeExp, fwdExp, upExp);
    goog.vec.Vec3.add(eyeExp, fwdExp, centerExp);

    // Compute the expected modelview matrix from a set of valid random vectors.
    goog.vec.Matrix4.