When you change the position or timing of active footsteps, the biped's animation changes accordingly, causing the biped to step into the footsteps in their new positions with the new timing.
Deactivating footsteps temporarily suspends changes to animation when footsteps are changed. When you move deactivated footsteps or change their timing, the biped still continues to do the same motion it did before footsteps were deactivated.
Footsteps should be deactivated when you make substantial changes to footstep timing or placement.
Footsteps are deactivated by selecting footsteps and clicking 
(Deactivate Footsteps) on the Footstep Operations rollout.
After making changes to the footsteps, click 
(Create Keys For Inactive Footsteps) in the Footstep Operations rollout. This will recreate keys for the biped and cause it to follow the footsteps.
Active footsteps are pale in color, while inactive footsteps are brightly colored. This coloring appears both on footstep icons in viewports and on footstep keys in the Dope Sheet.
When to Deactivate Footsteps
There are many situations where you will want or need to deactivate footsteps after activating them.
- When you move or rotate active footsteps substantially, you might find that the original keys generated are no longer appropriate for your animation. If this happens, deactivate footsteps, move the footsteps into the correct locations, and activate footsteps again.
- When changing footstep timing in the Curve Editor's Dope Sheet mode, you might receive an error message stating that what you are trying to do violates one of the rules of biped key placement. If this occurs, deactivate footsteps, make timing changes in the Dope Sheet, then activate footsteps again
- If you have a large number of active footsteps in the scene, moving footsteps and making timing changes can cause delays as all keys are adapted and updated. You might find your work is faster if you deactivate footsteps while making your changes.
- If you have activated footsteps then changed the default animation, then find you want to return to the default animation, you can deactivate footsteps and activate them again to recreate the default animation.
Activation/Deactivation Workflow
The fastest workflow with footsteps is to deactivate footsteps and make changes, reactivate footsteps and play the animation to check your work, and repeat this process until the footstep timing and placement are correct. However, deactivating and reactivating footsteps replaces any biped keys with the default animation for the current footstep pattern and timing.
For this reason, it is recommended that you work with footsteps exclusively first, ignoring the upper body animation, and deactivate and reactivate footsteps as needed. When the motion of the feet is perfect or near-perfect, only then should you adjust the biped animation manually. Otherwise, you will lose all your manual animation work every time you deactivate and reactivate footsteps.
Rules for Inactive Footsteps
When you click deactivate footsteps, only selected footsteps are deactivated. If you haven't made any changes to the default animation, it is recommended that you deactivate all footsteps. However, if you've changed or added animation keys to part of the animation, you might want to deactivate only a portion of the footsteps.
When some but not all footsteps are currently deactivated, limitations are imposed on the changes you can make to footsteps:
- You cannot set, delete, move, or edit keys in any way; footstep tracks are disabled in the Dope Sheet.
- You can create footsteps only when the new footsteps are among and adjacent to existing inactive footsteps.
- You can delete only inactive footsteps, and at least one inactive footstep must remain.
- You cannot deactivate a set of nonsequential footsteps.
Procedures
To deactivate footsteps:
Select the footsteps to deactivate.The footsteps you select must be in sequence; you cannot deactivate a nonsequential set of footsteps.
- On the Footstep Operations rollout, click (Deactivate Selected Footsteps).
The footsteps are deactivated. Viewports and the Dope Sheet display them in bright colors again.