Working with Timeline
The Unity Timeline has several Tracks that it can implement and we have already covered the Animation Track already. Activation Track is rather quite simple track to understand, just like how you can manually script objects to be activated and deactivated, with the the Unity Timeline, you are able to replicate the same function without any code.
Using the Activation Track:
Just like how to add in Animation Tracks, there are two methods in adding an Activation Track. You either click the + icon on the top left of the Timeline Window, or drag and drop the desired game object into the Timeline to trigger an drop down menu and select Activation Track.
Understanding Activation Track:
When you create an Activation Track it will be presented just like any other track. You are able to drag it across the timeline and create multiple instances of the same track along the timeline.
Wherever the Activation track isn’t active, then the object will not be enabled. An example can be seen below where only when the scrubber starts going over the Activated Track is when the wooden sphere shows. And when the track stops, the object is disabled.
Applications of this in games:
Activations Track are useful for animations that require to create illusions of objects disappearing. Examples include, if an character is picking up and object and placing it into an pocket or bag, or if an character is eating an object. We can have precise timed animations thanks to the timeline and activations tracks.
Activation Tracks can also create flickering illusions such has lamps or candles which need to have a certain sequence to their flickering.