I'd also be interested in how post-processing fits in with this. Like if you've got weather effects, film grain, tone mapping, etc, I would have thought the model would do better working on the image before those processes.
> I'd also be interested in how post-processing fits in with this.
I think screenspace effects like film grain and tonemapping are excluded in the same way UI elements are rendered separately from the game.
WoW goes to lengths to hide its depth buffer.