Is it possible using a great tiled background that apply the additive effect only on a figure (eg. a star)?
For example I've used two tiled background.
The first addition effect is used to tile the first sprite
The second addition effect instead is used to tile the second sprite.
The layout background colour is Grey-50.
This is the effect.
<img src="http://img534.imageshack.us/img534/8782/distorted.png">
The sprite 2 is distorted correctly
The sprite 1 would be distorted to the first tiled background only, instead the sprite is distorted both tiled background
The gray background wouldn't be distorted nor to the first tiled background neither to the second, instead is fully distorted.
This is the source:
http://www.box.net/shared/sfa47yxn6g
Sorry for my bad English.