How to access the scene

• The document currently open is a resource shared by the UI, the rendering core, and the python scripting system.
• In order to gain safe access to it, you must lock it up first.
• Most operations affecting the DAG, its nodes, attributes, connections, etc... may require that you notify the app to let the render engine be aware of the changes made.

In pseudo-code:

lock = MK_api.scoped_lock()
if ( lock.is_safe() ):
  dag = lock.get_dag()
  # ...
  # Safely RD/WR the DAG here...
  # ...
  reload_all()  # Optionally call this if changes were made.
lock.unlock()   # Call this to release the scene/DAG.