> Cascades sounds interesting. I'd certainly like to watch it. However, it 
> requires a more expensive GPU and a more expensive OS before it will even 
> consider running, so that's kind of the end of that.

You can watch it on YouTube, you might even be able to find a higher 
resolution version somewhere on the net.

http://youtube.com/watch?v=_tDK2hfxiw0

> Yes. And that is why POV-Ray can do things that a GPU can't. POV-Ray isn't 
> *trying* to be real-time. ;-)

So POV should strive to use more recent algorithms then, not just stick with 
ones that were around 20 year ago.

> I could add things like isosurfaces to the list.

You do realise that the big rock in the Cascades demo is an isosurface?

> (Have you ever seen a game where the water *actually ripples* rather than 
> just surface normal tricks?)

Yes, Crysis for one, plus there's some flight sim which is regularly cited 
in papers about this.  The method used is "vertex texture lookup", whereby 
the position of a vertex can be modified by a texture.  It is available from 
Vertex Shader 3 onwards (ie all cards less than a year or two old).  This 
means a heightfield can essentially be rendered on the GPU with little or no 
effort from the CPU.  If you're doing your water simulation on the GPU 
anyway, this saves a huge amount of bandwidth between the CPU and GPU.

> Just don't try to tell me a GPU can do everything POV-Ray can. ;-)

I'm not, I'm just saying that it can do *most* of what POV can, in a 
fraction of the time.  ANd when people do start to use POV for animations, 
they chop out all the graphical goodies anyway to make it render in less 
than a year...

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