Animation
From Joystiq:
Who says mo-cap is the technical capturing of data to create realistic, fluid motion in gaming that’s devoid of soul?
Anyone who knows anything about how to properly animate a skeleton? Seriously, compare Polar Express to any film made by Pixar (even the original Toy Story. I’m that confident about this). The difference is mind-boggling. Pixar even went so far as to put a disclaimer at the end of Ratatoullie stating that absolutely no motion capture or other production shortcuts were used in the making of the movie. Animation is inherently art, and while you can use motion capture as a basis for your intentions if you’re under some serious time constraints, there is nothing motion capture can do that a trained animator can’t do better. Nothing.
Now, as I said, if you’re under pressure to get all the character animation in a game done in an extremely short time frame (especially when you’re aiming for realistic and unique movements, like in sports games, where each player has their own way of moving), you’re likely going to need to fall back on motion capture just because studying that many people’s movements is a lot more time consuming than just having them come in and strap into a mo-cap suit. However, if Polar Express has taught us anything, it’s that un-altered motion capture is creepy. Just watching the in-game footage that’s spliced rather spastic-ly into the end of the video embedded in the linked article, the players look pretty good, and move rather well, but they just strike me as slightly undead. It’s the Uncanny Valley all over again, but while most people tend to focus on the visual appearance of these creepy specimens themselves, the way they move is just as important. Motion capture seems to be a really good way of quickly moving from the null end of the Uncanny Valley graph straight into the deepest part of the trough; it’s what the artists and animators do with that raw footage that ultimately determines whether their characters manage to crawl back out of that pit, but putting your full faith in the motion capture to solve all of your problems is a really bad idea.
So to answer Joystiq’s query in a less sarcastic manner, the people who have only seen un-edited mo-cap are likely to assert wholeheartedly that it’s quite devoid of soul. Well-utilized raw mo-cap footage, on the other hand, may be indistinguishable enough from hand-animated motion that for all intents and purposes, you could either suck the rest of the soul out of it and hit the wrong end of your target, or you can punch it up a notch and hopefully strike the sweet spot of realism/stylization and interest/creepiness.