Game Animation Tutorial 1: quick walk cycle in Character Studio (Page 2)

Now that his feet are bound to world space, you can select his vertical center of mass like you learned before (or by selecting the Bip01 object) and move him down in space slightly so his knees are somewhat bent. Here's a picture to illustrate.
Don't worry about how much you're bending them… it'll soon change. Next, select your right foot and move it in front of your character so the knee is almost straight. Select the opposite foot and move it behind the character till its knee is almost straight. You've just created his first step.
Now you need to make his legs do the opposite of each other halfway through the animation. Move your time slider to frame 12. Double click the thigh of your front leg. This will select the entire hierarchy for you. In the Keyframming rollout, click on the Copy Posture button (the white one with the v in it). Now click on the Paste Opposite button right below it. This will give the opposite leg the exact pose of the one you copied the posture for. Return to frame 0. Select the opposite leg, which should be the back leg and copy it's posture. Return to frame 12 and paste opposite again. Now both legs shuffle like the beginnings of a walk.

Return to frame 0 once again. Now you're going to copy his entire pose. If you click and hold on the copy posture button, more copy options will appear. The one you're looking for has a picture of a person on it, and it's called Copy Pose. Once it's selected, click on it. If that button is unelectable, it's because you don't have a Biped bone selected. Now that your pose has been copied, go to frame 24 and click on paste. Now when you press play, his animation will loop, but his feet are going through the ground. That's an easy fix. Whenever you paste a keyframe, it automatically does so without IK blending. Simply go back to your keyframes and set sliding keys for both new keys on both feet. Now you're feet will slide along the ground.


Next, return to frame 0 and select the foot of the back leg. Lock this foot in place by clicking on the appropriate Anchor Foot button to the right of the paste buttons in the Keyframing rollout. Move to frame 2. Notice your back foot didn't animate… that's because it's anchored. Set a sliding key for this foot and unlock it by deselecting the Anchor Foot button. Now, while still on frame 2, rotate your foot forward by about 25 degrees and move it back to where the knee looks almost fully extended. If your foot is not rotating from the ball of his foot, then before you rotate, select the Select Pivot button in the IK Key Info window and choose the blue dot on the ball of his foot. If you don't have pivot points at all, it's because you're next keyframe isn't a sliding frame… Make sure you're feet are always using IK blending for your own sanity.

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