begin()
Begins a new transaction for the current thread.
Declaration
class func begin()Discussion
The new transaction is nested within the thread’s current transaction, if there is one.
The first time you modify the scene graph during a pass through the run loop, SceneKit automatically creates a transaction and makes it the current transaction. (SceneKit commits that transaction when the next iteration of the run loops begins.) If you call this method to create a custom transaction before modifying the scene graph, your custom transaction becomes the current transaction.