Shifty Geezer said:
What I feel does need improving is moving graphics. It'd be much more realistic to lose the mocap animations and replace them with physics based IK skeleton animations.
The problem of completely simulating human motion has not been solved yet to a level that would be acceptable to the general audience. There's been procedural, footstep-based animation in character studio for 3ds max since 1996 or something, but it always looked horrible.
So while you may have something that looks right from a scientific viewpoint, it would still lack the emotion, the acting, that is added by either the mocap actor or the animator. You want an enemy to look menacing, powerful, you want your hero to sneak? All those things are the result of small touches that sometimes even have to be unrealistic to sell the animation to the audience. It's why we call both acting and animation an art, and science has not yet managed to proove that it can match the skills of a talented artist.
It is very evident to us in the production of CGI that as you start to apply algorithmic corrections to mocap data, it will start to loose it's realism, it's character, it's extra touch. This is why motion editing is usually performed by humans as well, and it's better to have guys with animation experience and talent to get good results. The computer still does not know how a confident walk cycle looks... unless you want to do robots only, and even those robots would lack any character.
The short answer is that you shouldn't expect more than the ragdoll physics that you've seen so far. Maybe fitting the feet on the ground with IK as well, but that's all - the animation cycles should still be created with mocap or keyframing.
It'd be much better to have faces modelled and animated on a muscle based system rather than using keyframed models.
Facial animation is even more reliant on artistic talents, in order to express emotions and thoughts. Thus, forcing the animator to think in muscle movements instead of expressions would limit their abilities - although this could be improved to a level by abstracting the controls (hiding the individual muscle movements by grouping them into expressions). But the bigger problem is that simulating something is always much more complicated and time consuming then manually creating the desired result.
Also, a simulation model is usually very slow, certainly slower than it's alternatives. You want to have it running at an interactive framerate, partially to allow fast feedback to the animator and partially because it should run in the game
To give an indication, the creatures in Hellboy used a muscle simulation system for the skinning of the body. Running a 10-30 second shot's simulation usually required a whole night's calculations on a large renderfarm of PCs. You'd need at least two orders of magnitudes of increase in computing power to be able to simulate just one of these creatures in real time.
Some game devs tend to mention that they're doing some kind of muscle simulation. In reality it's that they add a few extra bones into a character rig that try to act as muscles, with their movement manually tweaked by an artist to help with the trickier deformations.
For example, you could add an extra bone to 'simulate' the secondary movement of a woman's breast, but we all know that it doesn't have anything to do with true simulation as there aren't any bones in there