Model.readyPromise.then(function(Model) {

var boundingSphere = Model.boundingSphere;

viewer.camera.viewBoundingSphere(boundingSphere, new Cesium.HeadingPitchRange(0, -2.0, 0));

viewer.camera.lookAtTransform(Cesium.Matrix4.IDENTITY);

center = Model.boundingSphere.center;

var cartographic = Cesium.Cartographic.fromCartesian(boundingSphere.center);

var surface = Cesium.Cartesian3.fromRadians(cartographic.longitude, cartographic.latitude, 0.0);

var offset = Cesium.Cartesian3.fromRadians(cartographic.longitude, cartographic.latitude, heightOffset);

var translation = Cesium.Cartesian3.subtract(offset, surface, new Cesium.Cartesian3());

var heading = Cesium.Math.toRadians(10);

var pitch = Cesium.Math.toRadians(10);

var roll = Cesium.Math.toRadians(0);

var hpr = new Cesium.HeadingPitchRoll(heading, pitch, roll);

var result_teste = Cesium.Quaternion.fromHeadingPitchRoll(hpr,result_teste);

var rotacao = Cesium.Quaternion.subtract(result_teste,Cesium.Quaternion.IDENTITY, new Cesium.Quaternion());

var result = Cesium.Matrix4.fromTranslationQuaternionRotationScale(translation,rotacao , new Cesium.Cartesian3(1.0, 1.0, 1.0),result);

Model.modelMatrix =result;

});

I am trying that but it isn’t working. The model is disappering.

Have any ideia why?