drag()
Creates a field that slows any object in its area of effect with a force proportional to the object’s velocity.
Declaration
class func drag() -> SCNPhysicsFieldReturn Value
A physics field object. To use the field in a scene, attach it to the physicsField property of an SCNNode object.
Discussion
Like the damping and angularDamping properties of a physics body, drag fields can simulate effects such as fluid friction or air resistance. Unlike those properties, drag fields can simulate different intensities of fluid friction in different areas of your scene. For example, you can use a drag field to represent underwater areas.
The default falloffExponent value for a drag field is 0.0, indicating that the field’s effect is constant throughout its area of effect.