Loop fade in and out question?

Hello! I ran across two example files, one from Nivrams website (big thanks to Nivram on all these great examples) called Random Stars. Another one from Danny using a fade in/fade out example.

I thought it would be neat if I could edit Nivram's star example and see if I could make the stars twinkle, or fade in and out but running into some trouble. I tried to do a loop and noticed it wasn't working, then simplified it down to a "press space bar" and noticed the stars aren't coming back into view. Does anyone know what I'm doing wrong? Is it possible to loop this fade in/out example to make a twinkling star effect?

I uploaded an example.

Thanks everyone for your thoughts! :)

I'm not sure what you mean by twinkling exactly, but your spacebar event is disabling the group that is making the stars disappear while only making them slightly reappear(the -1 is out of 128). So to keep them disappearing you need to reactivate the transparency group. I just made their transparency random and change based on a timer. Attachment 15489

Bobjuzz, thank you so much - this is exactly what I was trying to achieve. That makes sense to me now, I wasn't understanding the transparency code apparently. This definitely looks like twinkling stars :) Love it!