At the recent motion capture shoot we decided to recapture the female locomotion. This includes walk, jog, and sprint, as these are the speeds you can move in the game. The previous data we captured for the female was a bit off. We simply were not happy with how it looked. The new data is much cleaner and looks more fluid and natural. The gif below is a looped gif, so there's a brief hiccup in the locomotion. That was a symptom of the gif, not the raw data. It will be perfect in-game.
The trickier parts for locomotion relates to starts/stops and blends. Let me explain. When you press forward on the thumbstick (on a controller) and the character was standing still, then should begin moving forward. If you barely press forward, they walk, if you push harder they jog. If you click in on the thumbstick, they sprint. But when we capture these movements they are independent. We ask the actor to walk and we capture that. Then we ask them to jog and we capture that. Lastly they run and we capture that. Then we cut the data down to just one cycle each. If it's a walk, one cycle would be each leg moving forward, and that's all we need. Same for jog and sprint. Once you have those cycles you have to then think about starts and stops. So with the same data, we pull the frames from when they first began the locomotion (walk, jog, and sprint) and we pull that frame. Same for when they stop. Next we pull the few frames that are just between the moments of starting and then top speed. Again we pull blends from all 3 cycles (walk, jog and sprint).
female_run_cycle.gif 538.77KB 9 downloads
With that said what you end up with is three starts, three stops, three blends and three speed cycles. Each only a few frames each. This allows the player to move the thumbstick and see the character react appropriately on-screen. It's a very time consuming process and it takes a real artist to get it right. If your data is off by one frame, it throws the whole cycle off. You'll get unnatural movement. Next you have to think about timing the frames to match foot speed. If this is off, you get "foot sliding". This is an effect that looks like the character is skating. If the timing of the locomotion is slower than the foot speed (think of it like miles per hour), then you get foot sliding. Same issue if the locomotion is too fast. It's very delicate. Artists/engineers are working in centiseconds within a frame.
So the next time you play a game and you notice your character walking, running, etc. Now you have a brief background on what it takes to make that look correct.