/// <summary>
 /// Adds a particle with a user-defined index for later manipulation
 /// </summary>
 public void AddParticle(Object3D part, int index)
 {
     // Store for later if Display isn't created yet
     if (Display == null)
     {
         initialParticles.Add(new Tuple <Object3D, int>(part, index));
     }
     else
     {
         Display.AddObject(part, index);
         particleDictionary.Add(index, part);
     }
 }