What is a Timeline in Unreal Engine?
The Timeline node is a unique Blueprint node in Unreal Engine that allow us to change a value over time.
For example, let’s say you want to change an object’s location in exactly two seconds. You can do it by using a Timeline.
Timelines can be useful for managing easy tasks, such as changing the position of objects or changing the color of lights in a scene. Using a Timeline node and some keyframes, you’ll be able to create output values like float numbers, vectors and colors.
How do I make a Timeline in Unreal Engine?
To create a Timeline node inside a Blueprint, simply right-click and type “Add Timeline…” in the search field.
When you create a Timeline in Unreal Engine, you can modify it by double-clicking on the timeline node.
After that, a new window will appear.
Be aware that Timelines cannot be used inside Widget Blueprints.
Timeline Inputs and Outputs
- Play: The Timeline will begin to play from its current position in time.
- Play from Start: The Timeline will start playing from the beginning, this is really useful for repeating animations.
- Stop: It will stop the timeline animation at the current time. It can be used to stop loops.
- Reverse: The Timeline will play backwards from its current position in time.
- Reverse from End: The Timeline will start playing in reverse, starting from the end and going backwards to the start.
- Set New Time: This input can be helpful if you want to start an animation from a particular point in time. It allows you to set the current time to a specific value using the “New Time” input.
- New Time: This float input is used along with the Set New Time input. It accepts a decimal value (called a float) that represents a point in time, measured in seconds, to which the Timeline will jump when the Set New Time input is executed.
- Update: As is plays, it will continue executing the blueprint scripting code.
- Finished: The blueprint won’t execute code until the timeline has finished playing. The Stop function does not trigger this.
- Direction: This output provides information on the Timeline direction, if it is playing forward or backward.
Custom Output Pins
Enter the Timeline and click “+Track” to add custom output pins.
- Float: Adds a new float track to the Timeline.
- Vector: Adds a new vector track (XYZ) to the Timeline.
- Event: By adding an event track, you can create a new execute output that triggers an event after a specific amount of time measured in seconds, or in specific keyframes.
- Color Track: Adds a new linear color track to the Timeline, for animating colors.
- Selected Curve Asset: Add an external curve to the Timeline. This button is only active if an external curve is selected in the Content Browser.
Timeline Editor in Unreal Engine
- Length: It is the maximum length of the curve or the Timeline in seconds. The default value it’s 5 seconds.
- Use last keyframe: If this option is turned off, the last keyframe of the animation will be skipped. This can be useful in preventing issues when an animation is looping.
- Autoplay: If enabled, this Timeline node will start playing as soon as the level begins and will not require any additional input to get started.
- Loop: When active, the Timeline animation will loop indefinitely unless stopped via the Stop input pin. If it’s not working, try to compile the Blueprint.
- Replicated: This option is for networking and online multiplayer, the Timeline animation will be replicated across clients.
- Ignore Time Dilation: If you’re using Time Dilation in your game, you can turn on this feature to ignore it.
- Tick Group: Select between “TG_PrePhysics“, “TG_DuringPhysics“, “TG_PostPhysics” and “TG_PostUpdateWork“.
- Reorder: Reorders tracks.
- Vector Track Selector: It allows to hide and lock the XYZ tracks.
- Zoom to Fit: Vertical and Horizontal.
- Time: Keyframe Time Value. Keyframe has to be selected.
- Value: Keyframe Value. Keyframe has to be selected.
- Keyframe: Press SHIFT + Left click on the line to create a keyframe, or just right-click and select “Add Key“. Then right-click on the Key, to select a key interpolation. Selected keys can be moved by just dragging it, and deleted by pressing the Delete key on the keyboard.
- Gradient: Gradient for Color Tracks.
Sliding Door Example
If you want to learn more about Timelines, check this tutorial for creating Sliding Doors in Unreal Engine.