The Tweener

The Tweener makes a new pose between two keys by dragging sideways. Instead of posing every joint of an in-between by hand, you slide toward the pose before or after, or push your pose further. After this page you can use its four types and know why it sometimes refuses to start.

Try the four types

Blue has keys on frames 1, 4 and 13, and the playhead is on frame 4. Onion skin shows the key before in red and the key after in blue.

Make an in-between pose

1. Move the playhead to a frame between two keys of the figure’s layer, in the timeline.
2. Select the figure. You can click figures while the Tweener is on; Shift-click adds or removes figures.
3. Click the Tweener in the tool bar on the left of the stage. Click its small arrow (or right-click it) to choose a type. The button takes the colour of the type: purple Breakdown, blue Blend to Neighbor, orange Push, green Relax.
4. Drag sideways anywhere on the stage and watch the pose change. The amount shows at the bottom of the stage. About 300 pixels is 100%; hold Shift for ten times finer steps.
5. Let go to keep it: the pose becomes a key on the playhead’s frame (or replaces the key already there). Press Esc or right-click before letting go to cancel.
6. Scrub before and after the frame and play it. Undo if you need another try.

A click without dragging changes nothing and adds nothing to undo. The Tweener has no keyboard shortcut of its own; with its button focused, ↓ or → opens the types and ↑/↓ pick one.

The four types

“Plain in-between” means the pose a Linear move would have on this frame. On frame 4 of a move from frame 1 to frame 13 that is a quarter of the way, not the middle. Breakdown at 50% is always the middle pose, whatever the frame.

Example, an arm swing: keys on frames 1 and 13. On frame 4, a Breakdown at 30% gives a pose close to the start. Bend the elbow by hand for some drag, then use Push to make that bend a bit stronger, or Relax if it looks too much.

When the Tweener refuses

It needs a key before and after the playhead on the figure’s own layer. A key on the playhead’s frame doesn’t count as one of them, so you can re-tween a key that sits between two others. It says no when:

• the playhead is on the first or last key, or outside the keys (there is nothing on one side);
• a neighbouring key is a blank, or the figure isn’t in it, or it is built differently there (another rig or attachment);
• the layer is hidden or locked.

Each layer uses its own keys, so two selected figures on different layers can have different neighbours. A key on an unrelated layer is never a neighbour. The Tweener works on up to 256 figures at once.

Pose, timing and easing

The Tweener only makes poses; it doesn’t move keys or change their easing. Where you put the new key changes the spacing: the same 30% pose on frame 3 or on frame 9 gives two different motions. When the speed feels wrong, look at the timing in the timeline and the easing. For the shape of an arc, use motion paths; for silhouettes, onion skin.

Questions

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