According documentation it is possible to allow user to over zoom beyond maximum zoom level by defining maxScale constraint on MapView to 0.
const mapView = new MapView({
container: "containerDiv",
map: map
});
mapView.when(lang.hitch(this, function(event){
mapView.constraints.maxScale = 0;
}));
But it doesn't work, MapView is always locked at basemap's maximum zoom level.
mapView.when(lang.hitch(this, function(event){
mapView.constraints.lods = [
// basemap's maximum zoom level
// extra zoom level
];
}));
Regards,
Flavie
.