I'm not sure, but I expect that they use a plain because it's possible to use a plain
<some shader techniques required a fairly dense detailed mesh, fresnel only needs a plain> - like they can generate it with code, maybe even to a specified size, but really in DBProX10 we should be able to use any shape, so what you've been doing should translate over nicely. Using a mesh for example and adjusting the vertices every loop to create waves should be doable.
With DX10 there is no need for extra cameras, because the textures can be rendered along with the main scene, so the performance will be far better than DX9. The problem with cameras is they are dependant on your frame rate, so if your getting 500fps then adding fresnel water is not biggie, if your getting 50fps then adding fresnel water is a very bad idea. FPSC runs at 30fps, if your PC struggles to keep up, then your running at 10fps. A FPS needs to run at >25fps, otherwise it's too slow to aim effectively and quickly becomes something to post about on the forums.
What we all want is these cool water effects and bloom and volumetric particles without ending up with a dull and slow game because of it. Even people who are complaining want that, they just don't know it yet. Wait till we get to see FPSCx10 in action, then it won't be such a tech demo argument. With lots of enemies and shaders on the go, well people will just want it and hopefully accept that DX9 can't compete on that level, regardless of hardware. Hopefully we'll see a video in the next newsletter.
