vortex()
Creates a field whose forces circulate around an axis.
Declaration
class func vortex() -> SCNPhysicsFieldReturn Value
A physics field object. To use the field in a scene, attach it to the physicsField property of an SCNNode object.
Discussion
The force on an object in a vortex field is tangential to the line from the object’s position to the field’s axis and proportional to the object’s mass. (The field’s axis is a line that is parallel to its direction vector and that passes through its center. For details, see the offset property.) For example, when a vortex field’s area of effect contains many objects, the resulting scene resembles a tornado: The objects simultaneously revolve around and fly away from the field’s center.
By default, a vortex circulates counterclockwise relative to its direction vector. To make it circulate clockwise, set the field’s strength property to a negative value.
The default falloffExponent value for a vortex field is 0.0, indicating that the field’s effect is constant throughout its area of effect.