Edit attributes of an emitter

The attributes of the emitter control the initial position, direction, quantity, and speed of the emitted particles. You can set the emitter options before you create the emitter, or you can create a default emitter and set the attributes after the emitter is created.

To set emitter options before creating the emitter

Select Particles > Create Emitter > or Particles > Emit from Object > .
The options window appears.
Set the options described in Set emitter attributes by typing entries.
Changes you make to the options window affect emitters you create after the changes.
Create the emitter.

To edit emitter attributes after creating the emitter

Select the emitter you want to edit.
Do one of the following:
- Display the Attribute Editor or use the Channel Box to set the attributes as described in Set emitter attributes by typing entries.
- You can edit the most commonly used emitter attributes with the workspace manipulators. See Change emitter attributes with workspace manipulators.
  TipYou can key the emitter position or parent the emitter to a moving object the same as for any other object. See the Animation guide for information on setting keys.
  If you see clumps of particles or irregular emission direction when you animate the motion of an emitter, try the following remedies to smooth the emission:
  
  Make sure the Playback Speed is set to Play every frame in the Playback Speed pulldown in the Time Slider category in the Window > Settings/Preferences > Preferences window.
  
  Increase the Rate or Max Distance setting in the emitter.
  
  Select Solvers > Edit Oversampling of Cache Settings to increase the Over Samples value.

Set emitter attributes by typing entries

You can set the following attributes in the options window, Attribute Editor, or Channel Box:

Change emitter attributes with workspace manipulators

You can use manipulators in the workspace to edit several emitter attributes:

Rate
Direction (directional point emitters only)
Spread (directional point, curve, and surface emitters only)
Speed
Normal Speed (curve and surface emitters only)
Tangent Speed (curve and surface emitters only)
Max Distance and Min Distance

The manipulators offer an interactive alternative to typing entries in the Attribute Editor.

To use a manipulator on an attribute

Select the emitter.
Select the Show Manipulator Tool from the Tool Box.
A yellow attribute manipulator appears next to the emitter object. Dolly towards the manipulator to get a clearer view. Initially the attribute manipulator controls the Rate setting. An attribute toggle also appears near the emitter. It controls which attribute you can manipulate.
Drag the dot next to the Rate to change its value.
Click the attribute toggle to display a different attribute.
Each time you click the attribute toggle, you display a different attribute manipulator. The manipulator is an icon (often a dot) you typically drag to change its value. Details specific to attributes are in Use manipulator icons. The color of the manipulator and attribute toggle indicates which is active. Yellow is active, blue is inactive.

After clicking the attribute toggle a number of times, you’ll see a display mode where all the manipulator icons are displayed without the attribute names. When you click an icon in this mode, the attribute name appears next to it. You can then manipulate the attribute. Click the attribute one more time and you’ll see the first manipulator displayed in the cycle—the Rate attribute.

Use manipulator icons

Most attribute manipulators work the same way. Drag the icon away from the emitter icon to increase the value. Drag toward the emitter icon to decrease the value. Attribute manipulators that require different manipulation techniques are described in the following topics.

NoteIn some instances, the line that represents an attribute is a relative value. For example, if you drag a Rate value to a number over 100, the line snaps back to a fixed position. This occurs so that you can drag the value as high as desired without losing sight of the manipulator in the workspace. Some lines and curves represent accurate measurements, for example, Max Distance.

Note also that the Max Distance and Min Distance dots indicate a range of emission. The two dots originally are superimposed. To improve your view of the dots, drag a dot until the two dots are visible.

Direction X, Y, Z

Click inside the blue box. A manipulator identical to the Move tool appears. Drag the center to move in all directions, or drag one of the arrows to move with directional constraint. This manipulator appears only for directional point emitters.

Spread

Drag the dot icon roughly perpendicular to the emission direction. This displays a cone that indicates the Spread angle. When you drag the dot, a line appears in the workspace indicating the direction you can drag.