Instance Property

particleVelocity

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

Declaration

@property(nonatomic) CGFloat particleVelocity;

Discussion

Particles begin moving at this speed in the direction determined by the birthDirection or emittingDirection property. Their directions and speeds may change thereafter according to the acceleration property or physics effects (see the affectedByGravity, affectedByPhysicsFields, and colliderNodes properties). You can randomize the speed of newly spawned particles with the particleAngularVelocityVariation property.

Particle speed is measured in units (of the local coordinate space containing the particle system) per second.

The default value is 0.0 units per second, specifying that newly emitted particles are stationary until otherwise influenced.

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

See Also

Managing Particle Motion

particleAngle

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

particleAngleVariation

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

particleVelocityVariation

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

particleAngularVelocity

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

particleAngularVelocityVariation

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

particleLifeSpan

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

particleLifeSpanVariation

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