Creating Walk and Run Cycles with Biped

Now that you have a feel for keyframe animation, it's time to get a little more complex. A simple walk cycle seems easy enough—just put one foot in front of the other—but you need to remember to swing the opposite arm, and there's a lot of secondary motion involved in a walk cycle that makes the walk believable, like swinging of the hips and raising and lowering of the shoulders.

Another key benefit to using Max's biped is that it understands all these complex secondary motions and can reproduce them while walking, running, and jumping using preset controls.

To make a biped follow a walk cycle, you need to define the number of steps that you want to take and then click within the scene to place the right and left footprints that the character will follow. The biped then knows all the motions to include to animate the character following the footsteps.

1. Select the Hicks character and open the Motion panel. Click the Load File button, and open the Hicks biped.bip file that you saved in Chapter 7. This loads a fresh copy of the biped without keys.

2. Click the Footsteps Mode button, and then click the Create Multiple Footsteps button to open a dialog box where you can specify the number of footsteps to take. Select to take eight steps and to start with the right foot. Then click the OK button to close the dialog box. The footprints are added to the scene in front of the Hicks character (see Figure 8.6).

3. Click on the Create Keys for Inactive Footsteps button to have Max calculate all the keys necessary to create the walking motion. This causes Hicks to snap to the default footsteps directly underneath him at frame 1. Drag the time slider to see Hicks walk calmly from footstep to footstep (see Figure 8.7).

Create Keys for Inactive Footsteps button

Footsteps Mode button

Create Multiple Footsteps button

Create Keys for Inactive Footsteps button

Footsteps Mode button

Create Multiple Footsteps button

Figure 8.6 Footsteps are added to the scene directly in front of the Hicks character.

Figure 8.7

After you calculate the keys, Hicks follows the footsteps with all the necessary motions.

Figure 8.7

After you calculate the keys, Hicks follows the footsteps with all the necessary motions.

If you want to change the direction that Hicks walks, just rotate the footsteps, and the biped makes the adjustments to follow the changed footsteps. You also have options to make the biped run and jump.

To make the biped run, you need to activate the Run button in the Footstep mode. With this button active, the Walk Settings dialog box changes to a Run dialog box (see Figure 8.8).

Figure 8.8

The Run Settings dialog box lets you define the number of footsteps and the stride width and height for each step.

Figure 8.8

The Run Settings dialog box lets you define the number of footsteps and the stride width and height for each step.

When you enable the Run button (or the Jump button), the biped changes the way it moves to match the footprints. For the run mode, the strides are longer and the body attains a higher vertical height between steps.

1. Select the Hicks character and open the Motion panel. Click the Load File button, and open the Hicks biped.bip file that you saved in Chapter 7. This loads a fresh copy of the biped without keys.

2. Click the Footsteps Mode button, and then select the Run button. After that, click the Create Multiple Footsteps button to open a dialog box where you can specify the number of footsteps to take. Select to take eight steps and to start with the right foot. Then click the OK button to close the dialog box. The footprints are added to the scene in front of the Hicks character (see Figure 8.9).

3. Click on the Create Keys for Inactive Footsteps button to have Max calculate all the keys necessary to create the running motion. This causes Hicks to snap to the default footsteps directly underneath him at frame 1. Drag the time slider to see Hicks run hectically.

Run button

Run button

Figure 8.9 Footsteps for the run cycle are added to the scene directly in front of the Hicks character

4. If you look closely at Hicks in the previous figure, you'll notice that his arms are tucked in too close to its body. To fix this, we need to spread his arms away from the body for each key. Select his upper arm bone and click the Symmetrical button. Then rotate his arm away from his body slightly. After that, select both forearm bones and bend them slightly. This puts Hicks in a much better position to run (see Figure 8.10).

0 0

Post a comment