The shape of the region of space where the system spawns new particles.
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 3.0+
To randomize the locations where new particles spawn, assign a geometry to this property. This geometry defines the shape of the space where new particles may spawn, and the
birth properties define locations within and directions relative to the shape. For example, assigning a sphere geometry causes particles to spawn at random locations along the surface of the sphere (or within the volume of the sphere, according to the
The default value is
nil, specifying that all new particles emit from a single point. For particle systems attached to a node, this point is the origin of the node’s coordinate system. For particle systems attached directly to a scene using the
add method, use that method's
transform parameter to specify the emission point.