contactNormal
The normal vector, in scene coordinate space, of a collision between a particle and a geometry in the scene.
Declaration
static let contactNormal: SCNParticleSystem.ParticlePropertyDiscussion
The contact normal property only applies to collision handler blocks (see the handle(_:forProperties:handler:) method and SCNParticleEvent.collision constant). Its value is a three-component vector (an array of three float values).