public void Execute()
        {
            if (particleEffect == null)
            {
                particleEffect = new ParticleEffect(parent, app, particleEffectName, positionScale, velocityScale, attachmentPointName, orientation);
            }

            parent.Add(particleEffect);
            for (int i = app.SelectedObject.Count - 1; i >= 0; i--)
            {
                app.SelectedObject[i].Node.UnSelect();
            }
            if (particleEffect.Node != null)
            {
                particleEffect.Node.Select();
            }
        }