velocity
The particle’s velocity vector in units (of scene coordinate space) per second.
Declaration
static let velocity: SCNParticleSystem.ParticlePropertyDiscussion
This property’s value is a three-component vector (an NSValue object containing an SCNVector3 value for particle property controllers, or an array of three float values for particle event or modifier blocks).
The particle system’s particleVelocity and particleVelocityVariation properties determine the initial speed of each particle.