How to use the terriajs-cesium/Source/Core/Matrix3.multiplyByVector function in terriajs-cesium

update : function(value) {
            scene.camera.position.x = CesiumMath.lerp(startPosition.x, endPosition.x, value.time);
            scene.camera.position.y = CesiumMath.lerp(startPosition.y, endPosition.y, value.time);
            scene.camera.position.z = CesiumMath.lerp(startPosition.z, endPosition.z, value.time);

            var enuToFixed = Transforms.eastNorthUpToFixedFrame(camera.position, Ellipsoid.WGS84);

            var enuToFixedRotation = new Matrix3();
            Matrix4.getRotation(enuToFixed, enuToFixedRotation);

            camera.up = Matrix3.multiplyByVector(enuToFixedRotation, initialEnuUp, camera.up);
            camera.right = Matrix3.multiplyByVector(enuToFixedRotation, initialEnuRight, camera.right);
            camera.direction = Matrix3.multiplyByVector(enuToFixedRotation, initialEnuDirection, camera.direction);
        },
        complete : function() {

var initialEnuToFixed = Transforms.eastNorthUpToFixedFrame(startPosition, Ellipsoid.WGS84);

    var initialEnuToFixedRotation = new Matrix4();
    Matrix4.getRotation(initialEnuToFixed, initialEnuToFixedRotation);

    var initialFixedToEnuRotation = new Matrix3();
    Matrix3.transpose(initialEnuToFixedRotation, initialFixedToEnuRotation);

    var initialEnuUp = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.up, initialEnuUp);

    var initialEnuRight = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.right, initialEnuRight);

    var initialEnuDirection = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.direction, initialEnuDirection);

    var controller = scene.screenSpaceCameraController;
    controller.enableInputs = false;

    scene.tweens.add({
        duration : durationMilliseconds / 1000.0,
        easingFunction : Tween.Easing.Sinusoidal.InOut,
        startObject : {
            time: 0.0
        },
        stopObject : {
            time : 1.0
        },
        update : function(value) {
            scene.camera.position.x = CesiumMath.lerp(startPosition.x, endPosition.x, value.time);
            scene.camera.position.y = CesiumMath.lerp(startPosition.y, endPosition.y, value.time);

durationMilliseconds = defaultValue(durationMilliseconds, 200);

    var initialEnuToFixed = Transforms.eastNorthUpToFixedFrame(startPosition, Ellipsoid.WGS84);

    var initialEnuToFixedRotation = new Matrix4();
    Matrix4.getRotation(initialEnuToFixed, initialEnuToFixedRotation);

    var initialFixedToEnuRotation = new Matrix3();
    Matrix3.transpose(initialEnuToFixedRotation, initialFixedToEnuRotation);

    var initialEnuUp = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.up, initialEnuUp);

    var initialEnuRight = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.right, initialEnuRight);

    var initialEnuDirection = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.direction, initialEnuDirection);

    var controller = scene.screenSpaceCameraController;
    controller.enableInputs = false;

    scene.tweens.add({
        duration : durationMilliseconds / 1000.0,
        easingFunction : Tween.Easing.Sinusoidal.InOut,
        startObject : {
            time: 0.0
        },
        stopObject : {
            time : 1.0
        },

var camera = scene.camera;
    var startPosition = camera.position;
    var endPosition = position;

    durationMilliseconds = defaultValue(durationMilliseconds, 200);

    var initialEnuToFixed = Transforms.eastNorthUpToFixedFrame(startPosition, Ellipsoid.WGS84);

    var initialEnuToFixedRotation = new Matrix4();
    Matrix4.getRotation(initialEnuToFixed, initialEnuToFixedRotation);

    var initialFixedToEnuRotation = new Matrix3();
    Matrix3.transpose(initialEnuToFixedRotation, initialFixedToEnuRotation);

    var initialEnuUp = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.up, initialEnuUp);

    var initialEnuRight = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.right, initialEnuRight);

    var initialEnuDirection = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.direction, initialEnuDirection);

    var controller = scene.screenSpaceCameraController;
    controller.enableInputs = false;

    scene.tweens.add({
        duration : durationMilliseconds / 1000.0,
        easingFunction : Tween.Easing.Sinusoidal.InOut,
        startObject : {
            time: 0.0
        },

var initialEnuToFixed = Transforms.eastNorthUpToFixedFrame(startPosition, Ellipsoid.WGS84);

    var initialEnuToFixedRotation = new Matrix4();
    Matrix4.getRotation(initialEnuToFixed, initialEnuToFixedRotation);

    var initialFixedToEnuRotation = new Matrix3();
    Matrix3.transpose(initialEnuToFixedRotation, initialFixedToEnuRotation);

    var initialEnuUp = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.up, initialEnuUp);

    var initialEnuRight = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.right, initialEnuRight);

    var initialEnuDirection = new Matrix3();
    Matrix3.multiplyByVector(initialFixedToEnuRotation, camera.direction, initialEnuDirection);

    var controller = scene.screenSpaceCameraController;
    controller.enableInputs = false;

    scene.tweens.add({
        duration : durationMilliseconds / 1000.0,
        easingFunction : Tween.Easing.Sinusoidal.InOut,
        startObject : {
            time: 0.0
        },
        stopObject : {
            time : 1.0
        },
        update : function(value) {
            scene.camera.position.x = CesiumMath.lerp(startPosition.x, endPosition.x, value.time);
            scene.camera.position.y = CesiumMath.lerp(startPosition.y, endPosition.y, value.time);

update : function(value) {
            scene.camera.position.x = CesiumMath.lerp(startPosition.x, endPosition.x, value.time);
            scene.camera.position.y = CesiumMath.lerp(startPosition.y, endPosition.y, value.time);
            scene.camera.position.z = CesiumMath.lerp(startPosition.z, endPosition.z, value.time);

            var enuToFixed = Transforms.eastNorthUpToFixedFrame(camera.position, Ellipsoid.WGS84);

            var enuToFixedRotation = new Matrix3();
            Matrix4.getRotation(enuToFixed, enuToFixedRotation);

            camera.up = Matrix3.multiplyByVector(enuToFixedRotation, initialEnuUp, camera.up);
            camera.right = Matrix3.multiplyByVector(enuToFixedRotation, initialEnuRight, camera.right);
            camera.direction = Matrix3.multiplyByVector(enuToFixedRotation, initialEnuDirection, camera.direction);
        },
        complete : function() {

function offsetFromHeadingPitchRange(heading, pitch, range, result) {
    pitch = CesiumMath.clamp(pitch, -CesiumMath.PI_OVER_TWO, CesiumMath.PI_OVER_TWO);
    heading = CesiumMath.zeroToTwoPi(heading) - CesiumMath.PI_OVER_TWO;

    var pitchQuat = Quaternion.fromAxisAngle(Cartesian3.UNIT_Y, -pitch, scratchLookAtHeadingPitchRangeQuaternion1);
    var headingQuat = Quaternion.fromAxisAngle(Cartesian3.UNIT_Z, -heading, scratchLookAtHeadingPitchRangeQuaternion2);
    var rotQuat = Quaternion.multiply(headingQuat, pitchQuat, headingQuat);
    var rotMatrix = Matrix3.fromQuaternion(rotQuat, scratchHeadingPitchRangeMatrix3);

    var offset = Cartesian3.clone(Cartesian3.UNIT_X, result);
    Matrix3.multiplyByVector(rotMatrix, offset, offset);
    Cartesian3.negate(offset, offset);
    Cartesian3.multiplyByScalar(offset, range, offset);
    return offset;
}

update : function(value) {
            scene.camera.position.x = CesiumMath.lerp(startPosition.x, endPosition.x, value.time);
            scene.camera.position.y = CesiumMath.lerp(startPosition.y, endPosition.y, value.time);
            scene.camera.position.z = CesiumMath.lerp(startPosition.z, endPosition.z, value.time);

            var enuToFixed = Transforms.eastNorthUpToFixedFrame(camera.position, Ellipsoid.WGS84);

            var enuToFixedRotation = new Matrix3();
            Matrix4.getRotation(enuToFixed, enuToFixedRotation);

            camera.up = Matrix3.multiplyByVector(enuToFixedRotation, initialEnuUp, camera.up);
            camera.right = Matrix3.multiplyByVector(enuToFixedRotation, initialEnuRight, camera.right);
            camera.direction = Matrix3.multiplyByVector(enuToFixedRotation, initialEnuDirection, camera.direction);
        },
        complete : function() {