public void SetVisualization( 
   VoxelVisualization visualization
)

{
  // Note: call within QueuedTask.Run()
  {
    //Change the visualization to Volume
    //e.g. for creating slices
    voxelLayer.SetVisualization(VoxelVisualization.Volume);

    //Change the visualization to Surface
    //e.g. to create isosurfaces and sections
    voxelLayer.SetVisualization(VoxelVisualization.Surface);
  }
}

{
  //Visualization must be surface or CanCreateIsosurface will return
  //false
  if (voxelLayer.Visualization != VoxelVisualization.Surface)
    voxelLayer.SetVisualization(VoxelVisualization.Surface);

  //Get the variable profile on which to create the iso surface
  var variable = voxelLayer.SelectedVariableProfile;
  //or use ...voxelLayer.GetVariableProfiles().First(....

  // o Visualization must be Surface
  // o Variable profile must be continuous
  // o Variable MaxNumberofIsoSurfaces must not have been reached...
  if (variable.CanCreateIsosurface)
  {
    //Do the create
  }
}

{
  // Note: call within QueuedTask.Run()
  {
    //Visualization must be surface
    if (voxelLayer.Visualization != VoxelVisualization.Surface)
      voxelLayer.SetVisualization(VoxelVisualization.Surface);

    //Get the variable profile on which to create the iso surface
    var variable = voxelLayer.SelectedVariableProfile;

    // o Visualization must be Surface
    // o Variable profile must be continuous
    // o Variable MaxNumberofIsoSurfaces must not have been reached...
    if (variable.CanCreateIsosurface)
    {
      //Note: calling create if variable.CanCreateIsosurface == false
      //will trigger an InvalidOperationException

      //Specify a voxel value for the iso surface

      var min = variable.Statistics.MinimumValue;
      var max = variable.Statistics.MaximumValue;
      var mid = (max + min) / 2;

      //color range (i.e. values that are being rendered)
      var renderer = variable.Renderer as CIMVoxelStretchRenderer;
      var color_min = renderer.ColorRangeMin;
      var color_max = renderer.ColorRangeMax;

      //keep the surface within the current color range (or it
      //won't render)
      if (mid < color_min)
      {
        mid = renderer.ColorRangeMin;
      }
      else if (mid > color_max)
      {
        mid = renderer.ColorRangeMax;
      }

      //Create the iso surface
      var suffix = Math.Truncate(mid * 100) / 100;
      variable.CreateIsosurface(new IsosurfaceDefinition()
      {
        Name = $"Surface {suffix}",
        Value = mid,
        IsVisible = true
      });
    }
  }
}