Modify or animate a generator
You can modify an applied generator in the Inspector or HUD, or by using onscreen transform controls. You can animate generator parameters with keyframes or behaviors, and you can use a generator as the basis for a particle system. After you customize a generator, you can save it to the Library for future use.
While each generator is unique, there are a small set of controls that are shared between all generators. For more information, see Controls common to all image generators.
Modify a generator in the inspector
Modify a generator using onscreen controls
As with any other image layer in Motion, you can make basic transform adjustments to an applied generator (modifying size, distorting, changing the anchor point, and so on) using onscreen transform handles. Changes to these basic transform parameters are reflected in the Properties Inspector. Additionally, some generators have specific onscreen controls—usually to adjust the Center or Offset parameter—that you enable by selecting the Adjust Item tool in the toolbar. The Spiral Drawing generator has unique onscreen controls that simulate a stator (ring) and a rotor (gear) of a spiral-drawing tool. These changes are reflected in the Generator Inspector. For more information about the transform tools, see Transform layer properties in the Canvas.
Select a generator in Layers list, Timeline, or Canvas.
In the toolbar, click and hold the 2D transform tools pop-up menu, then choose the Adjust Item tool.
Note: If the generator has no onscreen controls, the Adjust Item tool is not available.
In the center of the Canvas, the Center onscreen control or the Offset onscreen control appears (depending on the generator).
In the Canvas, drag the Center control or the Offset control to a new position.
The Offset or Center parameter is adjusted accordingly in the Generator Inspector.
Tip: Always adjust transform-related generator parameters (such as center and angle) using onscreen controls (or the controls in the Generator Inspector) rather than via the Properties Inspector; the equivalent controls in the Properties Inspector cause the generator to be resampled, resulting in a lower-quality output.
For more information about the Offset and Center parameters, see the controls descriptions for Image Generators.
Animate a generator using keyframes
Although most generators create static images, you can animate the parameters of a generator to create a moving texture over time.
In the Layers list, Canvas, or Timeline, select the generator you want to animate.
Move the playhead to the frame where you want the animation to begin, then press A to turn on keyframe animation recording.
In the Generator Inspector or using the onscreen controls (if available), adjust a generator parameter.
A keyframe is added to the parameter.
Move the playhead to the frame where you want to create the next keyframe, then adjust the generator parameter again.
Play the project (press the Space bar).
The animated generator parameters create a moving, changing texture based on your keyframes. If you’re satisfied with the result, press A again to turn off keyframe recording.
Note: For more information on keyframing, see Keyframing overview.
Animate a generator using behaviors
As with all other objects in Motion, you can apply Basic Motion, Parameter, or Simulation behaviors to a generator. The following example applies the Random parameter behavior to randomize the opacity of the Star generator, creating a flickering star.
Add the Star generator to your project and display the Generator Inspector.
In the Generator Inspector, move the pointer over the right side of the Spike Opacity parameter row.
The Animation menu (a downward arrow) appears.
Click the Animation menu for the Spike Opacity parameter, then choose Add Parameter Behavior > Randomize.
The Randomize parameter behavior is applied to the Spike Opacity parameter, and the Behaviors Inspector is displayed so you can adjust the Randomize parameters.
In the Behaviors Inspector, drag the Amount slider to the right to increase the randomization effect.
In the transport controls (under the Canvas), click the Play button (or press the Space bar).
Because the Randomize parameter behavior is applied to the opacity of the star spikes, the star appears to flicker. When a Parameter behavior is applied to a parameter in a generator, a behavior icon (a gear) appears in the Generator Inspector in the row for the affected parameter. In this example, the behavior icon appears in the Spike Opacity parameter row.
To increase or decrease the effect of the flicker, adjust the Randomize parameters (in the Behaviors Inspector). To jump to the Randomize parameters from the Generator Inspector, control-click Spike Opacity parameter name, then choose Randomize from the shortcut menu.
For more information on using Parameter behaviors such as the Randomize behavior, see Randomize.
Use a generator as a particle cell source
As with other objects, generators can be used as a source for particle cells. The following example uses the Soft Gradient generator. To give your particle system more flexibility and reduce processing strain on your computer, scale the generator down in the Generator Inspector.
Add the Soft Gradient generator to your project.
In the HUD or Generator Inspector, reduce the Radius value.
This example uses a Radius value of 40.
Reduce the Width and Height values.
In the Canvas, the gradient and its bounding box are scaled down.
With the generator still selected, do one of the following:
In the toolbar, click the Make Particles button.
After you add an emitter to the project, the new Emitter object is selected In the Layers list; a duplicate of the source object (the Soft Gradient generator) becomes an emitter cell for the new particle system; and the original source object (the Soft Gradient generator) is disabled.
In the Canvas, the emitter bounding box appears. You can transform the bounding box using the onscreen controls or controls in the Inspector. The particle appears in the Canvas in the same location as the original object. Although it appears as if the particle is selected, it is the bounding box for the emitter that is selected.
Press the Space bar to play the project.
Soft gradient particles are emitted.
You can change the particle color, emitter shape, scale, emission angle, birth rate, and so on in the Emitter Inspector or HUD. For more information on working with particles, see Particles overview.