need to restrict zoom in and zoom out from the page !

CesiumJS
1

How can i control zoom-in and zoom-out in my page?

Link : http://camsphere.canopussystems.com/camasphere/Apps/Sandcastle/gallery/login.html

2

That page does not load completely for me, but you can disable default zoom handling with:

viewer.scene.screenSpaceCameraController.enableZoom = false;