The most basic form of communication for objects. Scripts operate by listening for specific messages. Messages are sent by the game engine when an event occurs, or by a script to be received by another script. Each message can be accompanied by three generic parameters. Messages that are generated by the engine can also have extended parameters specific to the type of message.
A group of one or more properties with pre-set values. Instead of adding several properties to an object, and setting all of their values, a single metaproperty can be used. This makes it easy to quickly change the behaviour of one or more objects, and also makes it easy to remove or modify that behaviour. Also facilitates changes in object behaviour via scripted events.
The sequence of stages which the UI passes through when the game is played. Each stage is a menu screen, animation, or game mode.
SS2 doesn’t use a mission loop, or not the same kind of loop at least.
An object that can move and carry objects that are resting on it. The direction of movement is determined by marker objects. Moving terrain objects must have an OBB physics model.
A dynamic component of the game database. Objects have data associated with them as properties, and are associated with other objects using links. The meta-property type of link is used to establish a hierarchical relationship between all objects, and enables properties to be inherited. The object hierarchy is arranged with abstract objects, or archetypes, as parent nodes, and concrete objects as leaves. (Except that concrete room objects may also be parent nodes.) Each object is uniquely identified by a numeric ID. Abstract objects have negative IDs, and concrete objects have positive IDs. (Zero is an invalid object ID.)
Objects include both physical entities in the world, and non-physical objects that only interact with the game engine. In the editor, concrete objects mostly appear as object brushes, but are also associated with room brushes and flow brushes. Abstract objects are not associated with any brush.
A physics model for objects with flat sides. The object is a rectangular solid with a fixed rotational orientation. An OBB object will not freely rotate, and does not collide with terrain.