Instance Property


The range, in units per second, of randomized initial particle speeds. Animatable.


@property(nonatomic) CGFloat particleVelocityVariation;


Setting a nonzero value for this property randomizes the effect of the particleVelocity property. SceneKit randomly adjusts the initial speed of each particle by up to half the particleVelocityVariation value. For example, if the particleVelocity value is 10.0 units per second and the particleVelocityVariation value is 5.0 units per second, newly spawned particles have random velocities between 7.5 and 12.5 units per second.

The default value is 0.0 units per second, specifying no randomization.

You can animate changes to this property’s value. See Animating SceneKit Content.

See Also

Managing Particle Motion


The rotation angle, in degrees, of newly spawned particles. Animatable.


The range, in degrees of randomized initial particle angles. Animatable.


The initial speed, in units per second, for newly spawned particles. Animatable.


The initial spin rate, in degrees per second, of newly spawned particles. Animatable.


The range, in degrees per second, of randomized initial angular velocities for particles. Animatable.


The duration, in seconds, for which each particle is rendered before being removed from the scene. Animatable.


The range, in seconds, of randomized particle life spans. Animatable.