Keys and Curves

This document contains an overview of how to work with keys and curves within the Timeline editor in Blueprints.

Working with Keys

Each track can have any number of keys that define a time and value. The data is interpolated between these keys to calculate the value at any point during the Timeline.

Adding Keys

Keys are added by holding the Shift key and clicking in the gray bar.

Blueprint Timeline - Add Key

Editing Keys

The time and value of the key can be set by clicking on the key and entering the values into the time and value fields near the top of the track.

Blueprint Timeline - Key Values

Deleting Keys

Selected keys can be deleted by pressing the Delete key on the keyboard.

Moving Keys

To move a key along the timeline, select the key and then click and drag it. Multiple keys can be selected using the Ctrl key. Dragging horizontally updates the Time value of the key, while dragging vertically updates the Value.

Key Interpolation

By Right-clicking on a key, you can choose the interpolation type for a given key. Key interpolation only affects the curve between the key you interpolate for and the next key after that. For example, with all other keys set to Linear, and the center key (shown in orange) set to Cubic-Auto, this is how the track looks.

key_interpolation_example.png

The available interpolation types are as follows:

  • Auto

    Cubic-Auto.png

  • User

    Cubic-locked.png

  • Break

    Cubic-break.png

  • Linear

    Linear.png

  • Constant

    Clamped.png

External Curves

To the left of the main key area is a field where you can add an external curve asset from the Content Browser to that track. This is different than using the add_external_curve_button.png button, which creates a new track from a selected external curve.

External Curve Icon Description
external_curve_copy_button.png Use the curve selected in the Content Browser for this track.
external_curve_browse_button.png Browse in the Content Browser to select a curve for this track.
external_curve_internal_button.png Convert an imported external curve to an internal curve so that keys and curves can be edited.

However, you may also Right-click on any curve (with at least one key selected) and choose Create External Curve. This brings up a context window in which you can edit the path into which the curve asset will be saved. In doing this, you may then use this curve again on other timelines.

k2_timeline_createExternalCurve.png

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