cesium-glb.js

var viewer = new Cesium.Viewer('cesiumContainer', {
    infoBox : false,
    selectionIndicator : false,
    shadows : true
});

function createModel(url, height) {
    viewer.entities.removeAll();

    var position = Cesium.Cartesian3.fromDegrees(-123.0744619, 44.0503706, height);
    var heading = Cesium.Math.toRadians(135);
    var pitch = 0;
    var roll = 0;
    var hpr = new Cesium.HeadingPitchRoll(heading, pitch, roll);
    var orientation = Cesium.Transforms.headingPitchRollQuaternion(position, hpr);

    var entity = viewer.entities.add({
        name : url,
        position : position,
        orientation : orientation,
        model : {
            uri : url,
            minimumPixelSize : 128,
            maximumScale : 20000
        }
    });
    viewer.trackedEntity = entity;
}

var options = [{
    text : 'Aircraft',
    onselect : function() {
        createModel('http://localhost:31338/foox.glb', 3000.0);
    }
}];

Sandcastle.addToolbarMenu(options);