From VFXPedia

Working With Splines In The Timeline

The timeline also shows any splines that are attached to a tool. When the splines are collapsed, they are drawn over the tool's timeline bar. Clicking on the plus sign beside the tool's name in the menu will expand the display so that each spline has its own bar in the timeline.

Keyframes for the splines are normally represented as vertical bars rather than points to make them easier to manipulate.

Changing Keyframe Time

To change the timing of a spline's keyframe, use on of the following methods:

With The Mouse

Click-drag on the keyframe to position it to a new time. Multiple keyframes can also be moved in this fashion by box-selecting or Ctrl-clicking on the desired keyframes. There is no restriction to moving keyframes from a single spline. Keyframes from several splines can be selected and moved together.

The exact position of the dragged keyframe in time is displayed to the right of the spline toolbar when dragging, as well as in the status bar.

With The Toolbar

The time edit box in the Toolbar allows a new position in time to be entered for the selected keyframe or keyframes. Clicking on the Time button will switch it to time offset mode. Clicking again will set it to time scale mode. Both modes can be used to adjust the timing of multiple keyframes at once.

With The Spreadsheet

When the name of the tool is selected in the tool menu, the keyframes will be shown in the Spreadsheet view. The timing of each keyframe can then be edited directly in the spreadsheet.

See the documentation for the spreadsheet later in this chapter for additional details.

Duplicating Spline Keyframes

Keyframes and multiple keyframe selections can be duplicated. Select the keyframe(s) to be duplicated and, while holding down the Ctrl key, drag the spline segment to a position without keyframes. The cursor will change from the forbidden symbol to a sub selection cursor. The keyframes can be dropped without over-writing existing keyframes.

Time Stretching

Time Stretching allows a selected spline, or segment on that spline, to be proportionally stretched or squashed. To enable spline stretching, select this option from the context menu or click on the Time Stretching button in the toolbar.

If more than one keyframe is selected on the spline, the outer keyframes will be surrounded by two vertical purple bars. If no keyframes are selected, click-drag a rectangle to set the boundaries of the bars. The time stretcher can affect more than one spline at a time.

Click-drag on the purple vertical bars to stretch or shrink the timing of the spline segments within the bars. Move these bars back and forth to stretch or squash the spline segment in time.

To disable the time stretching mode, click on the toolbar button again or re-select Time Stretching from the context menu.

Showing Keyframe Values

Clicking on the Val button in the timeline ruler will reveal text boxes beneath each keypoint on a spline bar, showing the spline's current value. Click in the text box to edit the value.