setValueAtTime

setValueAtTime is a method available on animation `KeyframeEffect` objects in web animations. It is used to directly set the value of a specific property at a particular time within the animation's timeline. This allows for precise control over how an animation progresses, enabling the creation of complex and dynamic visual effects.

When `setValueAtTime` is called, it modifies the `KeyframeEffect` to include a new keyframe at the specified time. This new keyframe dictates the value that the target property should hold at that exact moment. The animation will then interpolate between existing keyframes and this newly set value. This method is particularly useful for creating animations with abrupt changes or for synchronizing animations with other events.

The method takes two arguments: the time at which to set the value, typically in seconds, and the value itself. The type of the value must be compatible with the CSS property being animated. For example, if animating `opacity`, the value would be a number between 0 and 1. If animating `color`, it would be a valid CSS color string. `setValueAtTime` is part of the Web Animations API, which provides a powerful and flexible way to animate elements on the web.