Map can only be set for 2D views and SceneLocal and SceneGlobal can only be set for 3D views.
Remarks
A map view can be used to show maps which display 2D data or scenes which display 3D data. This method can be used to switch between Local and Global for 3D.
publicvoid SetViewingModeToSceneLocal()
{
//Get the active map view.
var mapView = MapView.Active;
if (mapView == null)
return;
//Check if the view can be set to SceneLocal and if it can set it.
if (mapView.CanSetViewingMode(ArcGIS.Core.CIM.MapViewingMode.SceneLocal))
mapView.SetViewingModeAsync(ArcGIS.Core.CIM.MapViewingMode.SceneLocal);
}