public static SectionDefinition CreateHorizontalSectionDefinition()

{
  // Note: call within QueuedTask.Run()
  {
    if (voxelLayer.Visualization != VoxelVisualization.Surface)
      voxelLayer.SetVisualization(VoxelVisualization.Surface);
    voxelLayer.SetSectionContainerExpanded(true);
    voxelLayer.SetSectionContainerVisibility(true);

    //Create a section that cuts the volume in two on the horizontal plane

    //Use the SelectedVariableProfile to get the sections
    //via its associated volume
    var volume = voxelLayer.SelectedVariableProfile.Volume;
    var volumeSize = volume.GetVolumeSize();

    //Or use normal (0, 0, 1) or (0, 0, -1)...
    var horz_section = SectionDefinition.CreateHorizontalSectionDefinition();

    horz_section.Name = "Horizontal Section";
    horz_section.IsVisible = true;
    horz_section.VoxelPosition = new Coordinate3D(volumeSize.X / 2, volumeSize.Y / 2, volumeSize.Z / 2);

    volume.CreateSection(horz_section);
  }
}