The other thing redeemer, is in order to optimize for say, Radeon series cards, you have to know the secret handshake with the dirvers. While, yes, every card (pretty much) is able to render Direct3d and OpenGl, things like vertex shading, photon mapping, volumetric shadows, are not not NOT inherent opengl function, erego, the secret handshake necessary to not only begin thinking of optimization, but to even get advanced OpenGl function in the first place. I'd say Dr. Evil knows a bit more than someone like you.
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