Tutorials
Controls on a null
Turn a machine of gears from one keyed dial, each at its own speed, and change all their colors at once, with controls on a rig and Link to Control.
This page is also a lesson inside Phoenix: choose and start Controls on a null, and Phoenix points at each control as you go. It takes about 10 minutes.
To follow along here instead, download the starting document, controls-null.fla, and open it with .
A control is a setting with a name, kept on an instance of its own, for other instances to follow with Link to Control. Put the controls for a scene on one marker, often called a null, and you change many things from one place.
The Gears layer holds four gears named big1, small1, big2 and small2. The Rig layer is a guide layer, so it is never drawn in the movie; it holds a red crosshair named rig.
1. Select the rig
Press V for the Selection tool and click the red crosshair at the top left.
2. Open the Behaviors panel
Choose Window > Behaviors if it is not showing. It lists what is on the selection and the settings of each.
3. Add Angle Control
Click Add Behavior and choose Angle Control. Nothing moves: a control only holds a value, for others to follow.
4. Name it
Set Control name to Turn and press Enter. The gears will find the control by this name.
5. Key the angle
The playhead is on frame 1 and Angle (degrees) is 0. Click the dot beside it to key it on this frame: it becomes a filled diamond.
A keyed setting changes over time: Phoenix goes smoothly from each key to the next.
6. Go to the end
Click frame 96 in the timeline's ruler, or choose Control > Go To End.
7. Two turns
Set Angle (degrees) to 720. Because it is keyed, this makes a second key here: from frame 1 to 96 the control turns twice round.
8. Select the gears
Click the big gear on the left, then Shift-click the other three, so all four gears are selected.
9. Add Link to Control
Click Add Behavior and choose Link to Control. It goes on all four gears at once, and what you set now is set on all four.
10. Point it at the rig
Set Controls on to rig: choose it from the list, or click Pick and then the red crosshair.
11. Choose the control
Set Control name to Turn and press Enter. Change my is Same, so an angle turns each gear.
12. Play it
Press Enter, or click the play button in the timeline header. All four gears turn with the rig's angle, but they turn the same way, and their teeth run through each other.
13. Turn the small ones back
Press Enter again to stop. Click an empty part of the stage, then click the small gear in the middle and Shift-click the small one at the bottom.
Set Amount (percent) to -200. A small gear has half the teeth, so it turns twice as fast, and the minus turns it the other way.
14. Play it
Press Enter, or click the play button in the timeline header. Now the gears mesh. To change how the whole machine runs, you key only the rig: an ease, a pause, a turn back.
15. Add a color control
Press Enter again to stop. Click the red crosshair to select the rig, click Add Behavior and choose Color Control.
16. Name it
Set Control name to Accent and press Enter. Its color is orange to begin with.
17. Link the gears again
Select all four gears again, click Add Behavior and choose Link to Control. It goes below the first one, and the panel shows its settings.
18. Tint them
Set Controls on to rig, Control name to Accent, and Change my to Tint. Then set Amount (percent) to 50, so the gears keep some of their shading. They all turn orange.
19. Change the color
Click the red crosshair, click Color Control in the list, and set Color (#RRGGBB) to #2E9BFF. Every gear turns blue at once.
What you did
You drove a machine from one null: a keyed angle turns every gear at its own speed, and one color tints them all.
A Slider Control can size or fade things, a Point Control move them, and a Checkbox Control show or hide a set of them together. Key a control, and everything linked to it changes over time.
For everything this tutorial touches on, see Controls on a null.