A plug-in can control its interactive creation process in two primary ways:

• a plug-in can control its interactive creation process by providing a mouse callback called by 3ds Max, and the plug-in will interpret the input and change its parameters accordingly.
• a plug-in instance can be created programmatically (by 3ds Max or other plug-ins) given that the plug-in type (specified by the super and class id) has been registered with Max, and the creator knows the super and class ids. The plug-in instance is created with the default values of its parameters, but the creator can modify them by getting to the plug-in's paramblock and modifying its parameters programmatically. The creator is responsible for hooking the up the created plug-in instance into the scene (ex: create a node for it, apply it to a node, if it's a material that was created, etc).