Create 3D particles

Two emitter pattern styles in the Shape pop-up menu have 3D options: Box and Sphere. The Box and Sphere shape options are available only when the 3D checkbox is selected in the Emitter Inspector.

Although the Rectangle, Circle, Line, Wave, Image, and Geometry emitter shapes have no inherent 3D parameters, they can be moved and rotated in 3D space. Additionally, the Line and Wave emitter shapes have quasi-3D properties: Their start and end points can be moved into Z space (depth).

Canvas showing particles from a 2D line emitter adjusted in 3D space

And when you nest an emitter in a 3D group, you can use Simulation behaviors to pull particles out of their X and Y planes, into Z space.

Turn an existing 2D particle system into 3D particles

After adding an emitter to a project, select the 3D checkbox in the Emitter Inspector.
For information about adding an emitter, see Add preset particles or create custom particles.
If your project does not contain a camera, click the New Camera button in the toolbar.
If your project is a 2D project, a dialog appears asking if you want to switch your 2D groups to 3D.
Click Switch to 3D.
A camera is added to the project, and your layers are turned into 3D layers.
In the 3D view tools (in the upper-right corner of the Canvas), drag in the Orbit tool (the center tool).
As the camera rotates, you can see that the particles are emitted in X, Y, and Z space (all three dimensions).
Tip: Use Simulation behaviors to create animated particles in 3D space that interact with other objects in the project. For example, use Orbit Around to create particles that circle around a target object. For more information, see Simulation behaviors overview.
Optional: If you want the particles to face the camera as it rotates around the emitter, select the Face Camera checkbox in the Emitter Inspector.

Create a 3D box or sphere particle emitter

After adding an emitter to a project, select the 3D checkbox in the Emitter Inspector.
For information, see Emitter controls.
In the Emitter Inspector, click the Shape pop-up menu, then choose Box or Sphere.

Particles emanate from a box or sphere pattern, in 3D space.

Make particles intersect with other layers

Particles can intersect with other rotated layers in 3D space.

In the Emitter Inspector, click the Render Particles pop-up menu, then choose In Global 3D (Better).
In the following image on the left, with Global 3D selected, particles intersect with other objects in the project that are transformed in 3D space. In the image on the right, with Local 3D selected, particles do not intersect with other objects.