I just want to throw this in:
"Photo realism" is an interesting term because, as we all know, photos don't move and the goal of the 3D mainly discussed here is about moving images. Very rapidly moving images. That is to say, the focus is on real-time 3D hardware and not 3D rendering such as Lightwave/Renderman where you put data in and ask for a single frame out; or a sequence of frames for offline animation as is often the case. So, with this in mind and accepting certain limitations when real-time is needed (let's say at least 30 fps), I would just like to inject the idea that it is detailed animation that will give the wow effect.
You can make a very statically detailed face and it will look good in a photo, but it may also look very strange in motion (at least when the viewer is considering the scene to be "in motion," but it may be perfectly still and odd looking). You might think of comments like "you look and act like a robot" with people who show very little emotion in their face. Emotion is dynamic, as in we relate to the face changing its form (eyebrows rising, lips curling, etc). If you always wore the exact same smile it would stop becoming recognized as your emotion (and then you'd be thrown into an asylum, but I digress...
) So, I think it's possible to make faces that are not very detailed upon close scrutiny of the static details, but that come through as being realistic and life-like in their detailed dynamics.
After all, you recognize this:
as a smiling face, but it looks nothing like one you might see in nature. Very little more is needed to make you believe it to be a living thing if it is artistically animated.
Ok, I don't know if this helped or hurt the discussion. Just wanted to toss that in there
