stretchFactor
A multiplier for stretching particle images along their direction of motion. Animatable.
Declaration
var stretchFactor: CGFloat { get set }Discussion
Use this property to create visual effects that show streaks of motion, such as fireworks. If the orientationMode property value is SCNParticleOrientationMode.free, a non-default stretch factor stretches particle images in the y-axis direction of each particle’s local coordinate space.
The default value is 0.0, specifying that particle images maintain their original aspect ratio.
You can animate changes to this property’s value. See Animating SceneKit Content.