doubt about how to stop an expression in a point / keyframe

• Choose a suitable animation software or tool that allows for keyframe manipulation, ensuring it meets your project requirements and workflow.

• Familiarize yourself with the documentation and guidelines provided by the chosen software to understand keyframe management features and capabilities.

• Locate the specific keyframe in your timeline where you want to stop the expression, ensuring you have selected the correct layer or property.

• Implement the expression on the desired property using the software's scripting or expression feature, ensuring it functions as intended.

• Set a keyframe at the point where you want the expression to stop affecting the property, ensuring it captures the desired value.

• Disable or delete the expression at the keyframe where you want to halt its influence, allowing the property to maintain its last keyframed value.

• Test the animation playback to confirm that the expression stops at the intended keyframe without affecting subsequent animations.

• Adjust the timing and interpolation of the keyframes like tool to achieve a smooth transition between the expression and the static value.

• Utilize the software's preview features to visualize how the expression interacts with the keyframes in real-time.

• Monitor performance and ensure that the use of expressions does not impact the overall rendering time or playback quality.

• Consider implementing additional features like easing functions at the keyframe to enhance the visual impact of the transition.

• Stay informed about updates or new tools that can improve keyframe management and expression handling, leveraging resources like community forums or tutorials.

In general, you could do this with an if statement like this

if(time < 10){
// PUT YOUR ORIGINAL LOOP EXPRESSION HERE 
}
else {
value
}

Now the loop is only active for the first 10 seconds (due to the condition "time < 10") and after that the normal keyframes are used

In the special case of a walk cycle, you can use the iExpressions walk cycle (part of the iExpressions Physics Bundle).

Then the character walks automatically when you move the character or the ground and stops walking when it does not move anymore. And you can still keyframe it on top of this walk cycle easily.

See these tutorials:

Finally, Expression Timeline is a very flexible and general solution to start, stop and fade expressions:

Expression Timeline 2 - aescripts + aeplugins - aescripts.com