New instances of classic plugin classes are typically created using a static "Alloc" function. The initial values of this instance are defined in an "Init" function. When an instance is deleted, its "Free" function is called.
A static "Alloc" function creates a new instance of a plugin class. This "Alloc" function is referenced in the corresponding "Register" function (see General Plugin Information Manual).
Each class derived from NodeData can implement NodeData::Init(). This "Init" function is called every time when an instance of the plugin class is allocated. In this "Init" function one can define the default values of parameters and internal data instead of using a class constructor.
Each class derived from NodeData can implement NodeData::Free(). This function is called when an instance gets freed. Implement this function to free internal data.