The latest Pixar adventure, The Incredibles, opens today, and is getting good reviews so far. I expect it to be every bit as fun as the other Pixar masterpieces (Toy Story; Monsters, Inc.; Finding Nemo). There have been tremendous advances in CGI technology and software since the first movie came out, and Dreamworks has pulled out some doozies too (the Shrek movies).
And yet, something major is still missing from CGI. It’s gravity.
No matter how complex they manage to get the muscle movements, light, wind, textures and detail, the eye misses the micro-movements that gravity creates: the slight downward movement of a body as it strains against gravity to jump; the small ripples through a mass as it lands. No matter how incredibly detailed a body is, it still looks as though it doesn’t weigh anything, and the brain notices in spite of itself.
Pixar has fudged this in the past by animating characters for whom this wouldn’t matter—for example, toys, which you expect to be plastic and lightweight, and that’s how they look. They moved on to monsters, which didn’t have to look real either. And then, once they got the algorithms for water down, they went to fish, which float and swim. Now that they’re bringing out an all-human feature, they buy themselves a little time by making them superheroes, for whom the laws of gravity and motion don’t necessarily apply.
I always love the animating skill and richness of the Pixar movies. But my eye always misses something, and the characters will always look especially cartoonish to me. Ice Age, in my opinion, dealt with this really well by going with it and making the characters very exaggerated and cartoonish on purpose. I think the animators will have to continue working around this problem until they solve it (which may take a lot more computing power than is possible today). In the meantime, though, we can enjoy the animation for what it is: not an imitation of reality, but a welcome surreality.
I highly recommend it. It will quickly be added to my by on dvd list when I can get it. 
Thanks for giving me an explanation for what I’m seeing. I’ve always been the guy that looks at this stuff and can’t get away from that little itching feeling that something’s not right.