CCLiquid renders my screen black
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I am using cocos2d-iphone, latest non-beta version.

Recently I found this: http://www.cocos2d-iphone.org/wiki/doku.php/prog_guide:effects, and I was interested in CCLiquid or CCWaves for some water effects in my game.

However, when I apply CCLiquid action on my CCSprite, everything but the sprite itself is rendered black. Well, not exactly. When I increased the amplitude of the action, I noticed that it was actually a black background the size of the screen generated directly below my CCSprite (and such background was also being "waved").

Even though this is not a 3D action (no 3D suffix at least), I decided to follow the tip on that page and put this on my delegate:

    [[CCDirector sharedDirector] setDepthBufferFormat:kDepthBuffer16];

But `kDepthBuffer16` is not recognized anyway.

Any ideas?