Expression Controls draw nothing. Each holds one animatable value that expressions can read, so you can build rigs with named controls. They are in the Effects ▸ Expression Controls submenu.
On a null layer, the Effects section sits above Transform and opens by default, since nulls usually exist to carry controls.
The controls
| Control | Parameter | Value | Default | Expression |
|---|---|---|---|---|
| Slider Control | Slider | A number, −1,000,000 to 1,000,000 | 0 | effect("Slider Control")("Slider") |
| Angle Control | Angle | Degrees | 0 | effect("Angle Control")("Angle") |
| Checkbox Control | Checkbox | On/off, read as 1 or 0 | Off | effect("Checkbox Control")("Checkbox") |
| Point Control | Point | An X, Y point | 0, 0 | effect("Point Control")("Point") |
| Color Control | Color | A color, read as [r, g, b, a] from 0 to 1 | Red | effect("Color Control")("Color") |
How to use them
- Select a layer (often a null) and choose a control from Effects ▸ Expression Controls.
- Double-click its name in the Effects section to rename it, for example "Speed".
- Refer to it by that name in an expression:
effect("Speed")("Slider").
Tips
- Expressions find effects by name, so rename before writing expressions. Renamed controls from After Effects keep their names on import.