[James]

thnaks for the lession ...I got more idea about how the order of screen pixel painting now....
so it just like a loop ABCABCABC.....in a ring.....this is the troublesome always appears in programming.....I've experience that b4 as well.....:

sometimes I found that Yellow Tang's tail become black when it's turning.....but the foreground and background light are all completely on......and sometimes Golden Butterflyfish too...
guess it's for the same reason?


btw,I found another strange effect on starfish.....
I turned on the wireframe mode when my starfish in on the glass...a few seconds later....the starfish suddenly "teleport" itself off the glass and start floating down....it all happens in wireframe mode.....then I switch back to normal mode...and the starfish really floating down to the bottom....
then I go check into the control panel.....
the starfish allow on glass is still checked......
I wonder why......