你想使用入口系统时，都需要在场景树中包含特殊的节点，叫做 RoomManager。RoomManager 负责系统的运行维护，特别是将你的房间中的对象转换为房间图，在运行时用于进行遮挡剔除和其他任务。
This conversion must take place every time you want to activate the system. It does not store the room graph in your project (for flexibility and to save memory). You can either trigger it by pressing the Convert Rooms button in the editor toolbar (which also has a keyboard shortcut) or by calling the
rooms_convert() method in the RoomManager. The latter method will be what you use in-game. Note that for safety, best practice is to call
rooms_clear() before unloading or changing levels.
If you convert the level while the editor is running, the portal culling system will take over from the normal Godot frustum culling, potentially interfering with editor features. To get around this, you can turn portal culling on and off using either the View Portal Culling toggle in the View menu on the editor toolbar (which also has a keyboard shortcut) or the Active setting in the RoomManager node.
To use the RoomManager, you have to tell it where the rooms are in your scene tree, or, more specifically, where the RoomList node is. This RoomList is the parent of your rooms - see below. If the RoomList is not set, conversion will fail, and you will see a warning dialog box.
Before we create any rooms, we must first create a node to be the parent of all the static objects, rooms, roomgroups, and so on in our level. This node is referred to as the the
The roomlist is not a special node type – it can just be a regular Spatial.
You will need to assign the roomlist node in the RoomManager so that it knows where to find the rooms.
Why do we use a specific branch of the scene tree and not the scene root? The answer is that there are many internal details of the system which are easier to manage if the rooms are placed on their own branch.
Often you will end up completely replacing the roomlist branch at runtime in your game as you load and unload levels.
Rooms are a way of spatially partitioning your level into areas that make sense in terms of level design. Rooms often quite literally are rooms (like in a building). Ultimately though, as far as the engine is concerned, a room represents a non-overlapping convex volume in which you typically place most of your objects that fall within that area.
A room doesn't need to correspond to a literal room. It could, for example, also be a canyon in an outdoor area or a smaller part of a concave room. With a little imagination, you can use the system in almost any scenario.
Rooms are defined as convex volumes (or convex hulls) because it's trivial to mathematically determine whether a point is within a convex hull. A simple plane check will tell you the distance of a point from a plane. If a point is behind all the planes bounding the convex hull, then by definition it is inside the room. This makes all kinds of things easier in the internals of the system, such as checking which room a camera is within.
If you accidentally create overlapping rooms, the editor will warn you when you convert the rooms, indicating any overlapping zones in red.
The system does attempt to cope with overlapping rooms as best as possible by making the current room "sticky". Each object remembers which room it was in during the previous frame and stays within it as long as it does not move outside the convex hull room bound. This can result in some hysteresis in these overlapping zones.
There is one exception, however, for internal rooms. You do not have to worry about these to start with.
Room 是一种节点类型，可以像其他类型一样添加到场景树。将对象添加为 Room 节点的子级，以放置在房间内。
因为定义房间边界是系统最重要的方面，因此在 Godot 提供三种方法来定义房间的形状：
Manually edit the points that define the convex hull in the room inspector or drag the points around using the editor gizmo (see 编辑房间点).
Provide a manual bound. This is a MeshInstance in the room that has geometry in the shape of the desired bound, with a name with the postfix
-bound. This is something you might choose to do if you create your levels in Blender or similar (see 在 Blender 中创建房间系统（或者其他建模工具）).
While the first option can be all that is required, particularly with simple rooms or for pre-production, using manual bounds gives you ultimate control at the expense of a small amount of editing. You can also combine the two approaches, perhaps using automatic bounds for most rooms but manually editing problem areas.
If you create some rooms, place objects within them, then convert the level in the editor, you will see the objects in the rooms appearing and showing as you move between rooms. There is one problem, however! Although you can see the objects within the room that the camera is in, you can't see to any neighbouring rooms! For that we need portals.
Portals are special convex polygons that you position over the openings between rooms in order to allow the system to see between them. You can create a portal node directly in the editor. The default portal has 4 points and behaves much like a
plane MeshInstance. You can add or remove points using the inspector. A portal requires at least 3 points to work - this is because it needs to form a polygon rather than a point or line.
To save editing effort, only one Portal is required between each pair of Rooms. You do not need to (and indeed should not) create two Portals that overlap in opposite directions. Portals default to being two-way, but you can make them one-way in the Portal inspector.
By now you should be able to create a couple of rooms, add some nodes such as MeshInstances within the rooms, and add a portal between the rooms. Try converting the rooms in the editor and see if you can now view the objects in neighbouring rooms through the portal.