public sealed class VoxelLayer : Layer, ArcGIS.Desktop.Core.IMetadataInfo, IMetadataSource, System.ComponentModel.INotifyPropertyChanged  

//Map must be a local scene
bool canCreateVoxel = (MapView.Active.ViewingMode == MapViewingMode.SceneLocal);

if (canCreateVoxel)
{
    //TODO - use the voxel api methods
}

//Must be on the QueuedTask.Run()

//Must be a .NetCDF file for voxels
var url = @"C:\MyData\AirQuality_Redlands.nc";
var cim_connection = new CIMVoxelDataConnection()
{
    URI = url
};
//Create a VoxelLayerCreationParams
var createParams = VoxelLayerCreationParams.Create(cim_connection);
createParams.IsVisible = true;

//Can also just use the path directly...
//var createParams = VoxelLayerCreationParams.Create(url);

//Use VoxelLayerCreationParams to enumerate the variables within
//the voxel
var variables = createParams.Variables;
foreach (var variable in variables)
{
    var line = $"{variable.Variable}: {variable.DataType}, " +
       $"{variable.Description}, {variable.IsDefault}, {variable.IsSelected}";
    System.Diagnostics.Debug.WriteLine(line);
}
//Optional: set the default variable
createParams.SetDefaultVariable(variables.Last());

//Create the layer - map must be a local scene
VoxelLayer voxelLayer = LayerFactory.Instance.CreateLayer<VoxelLayer>(createParams, map);

//Get selected layer if a voxel layer is selected
var voxelLayer = MapView.Active.GetSelectedLayers().OfType<VoxelLayer>().FirstOrDefault();
if (voxelLayer == null)
{
    //just get the first voxel layer in the TOC
    voxelLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType<VoxelLayer>().FirstOrDefault();
    if (voxelLayer == null)
        return;
}

//var voxelLayer = ...
//Must be on the QueuedTask.Run()

//Toggle containers and visibility in the TOC
voxelLayer.SetExpanded(!voxelLayer.IsExpanded);
voxelLayer.SetVisibility(!voxelLayer.IsVisible);
voxelLayer.SetIsosurfaceContainerExpanded(!voxelLayer.IsIsosurfaceContainerExpanded);
voxelLayer.SetIsosurfaceContainerVisibility(!voxelLayer.IsIsosurfaceContainerVisible);
voxelLayer.SetSliceContainerExpanded(voxelLayer.IsSliceContainerExpanded);
voxelLayer.SetSliceContainerVisibility(!voxelLayer.IsSliceContainerVisible);
voxelLayer.SetSectionContainerExpanded(!voxelLayer.IsSectionContainerExpanded);
voxelLayer.SetSectionContainerVisibility(!voxelLayer.IsSectionContainerVisible);
voxelLayer.SetLockedSectionContainerExpanded(!voxelLayer.IsLockedSectionContainerExpanded);
voxelLayer.SetLockedSectionContainerVisibility(!voxelLayer.IsLockedSectionContainerVisible);

ArcGIS.Desktop.Mapping.Events.MapMemberPropertiesChangedEvent.Subscribe((args) =>
{
    var voxel = args.MapMembers.OfType<VoxelLayer>().FirstOrDefault();
    if (voxel == null)
        return;
    //Anything changed on a voxel layer?
    //At 2.x - if (args.EventHints.Any(hint => hint == MapMemberEventHint.VoxelSelectedVariableProfileIndex))
    if (args.EventHints.Any(hint => hint == MapMemberEventHint.VoxelSelectedVariable))
    {
        //Voxel variable profile selection changed
        var changed_variable_name = voxel.SelectedVariableProfile.Variable;
        //TODO respond to change, use QueuedTask if needed

    }
    else if (args.EventHints.Any(hint => hint == MapMemberEventHint.Renderer))
    {
        //This can fire when a renderer becomes ready on a new layer; the selected variable profile
        //is changed; visualization is changed, etc.
        var renderer = voxel.SelectedVariableProfile.Renderer;
        //TODO respond to change, use QueuedTask if needed

    }
});

ArcGIS.Desktop.Mapping.Voxel.Events.VoxelAssetChangedEvent.Subscribe((args) =>
{
    //An asset changed on a voxel layer
    System.Diagnostics.Debug.WriteLine("");
    System.Diagnostics.Debug.WriteLine("VoxelAssetChangedEvent");
    System.Diagnostics.Debug.WriteLine($" AssetType: {args.AssetType}, ChangeType: {args.ChangeType}");

    if (args.ChangeType == VoxelAssetEventArgs.VoxelAssetChangeType.Remove)
        return;
    //Get "what"changed - add or update
    //eg IsoSurface
    VoxelLayer voxelLayer = null;
    if (args.AssetType == VoxelAssetEventArgs.VoxelAssetType.Isosurface)
    {
        var surface = MapView.Active.GetSelectedIsosurfaces().FirstOrDefault();
        //there will only be one selected...
        if (surface != null)
        {
            voxelLayer = surface.Layer;
            //TODO respond to change, use QueuedTask if needed
        }
    }
    //Repeat for Slices, Sections, LockedSections...
    //GetSelectedSlices(), GetSelectedSections(), GetSelectedLockedSections();
});