Portal nodes are used to enable visibility between [Room]s.
[Portal]s are a special type of [MeshInstance] that allow the portal culling system to 'see' from one room to the next. They often correspond to doors and windows in level geometry. By only allowing [Camera]s to see through portals, this allows the system to cull out all the objects in rooms that cannot be seen through portals. This is a form of [b]occlusion culling[/b], and can greatly increase performance. There are some limitations to the form of portals: They must be single sided convex polygons, and usually you would orientate their front faces [b]outward[/b] from the [Room] they are placed in. The vertices should be positioned on a single plane (although their positioning does not have to be perfect). There is no need to place an opposite portal in an adjacent room, links are made two-way automatically.
Sets individual points. [b]Note:[/b] This function will not resize the point array. Set [member points] to set the number of points.
- This is a shortcut for setting the linked [Room] in the name of the [Portal] (the name is used during conversion).
- The points defining the shape of the [Portal] polygon (which should be convex). These are defined in 2D, with [code]0,0[/code] being the origin of the [Portal] node's [member Spatial.global_transform]. [b]Note:[/b] These raw points are sanitized for winding order internally.
- Visibility through [Portal]s can be turned on and off at runtime - this is useful for having closable doors.
- Some objects are so big that they may be present in more than one [Room] ('sprawling'). As we often don't want objects that *just* breach the edges to be assigned to neighbouring rooms, you can assign an extra margin through the [Portal] to allow objects to breach without sprawling.
- Portals default to being two way - see through in both directions, however you can make them one way, visible from the source room only.
- In most cases you will want to use the default [Portal] margin in your portals (this is set in the [RoomManager]). If you want to override this default, set this value to [code]false[/code], and the local [member portal_margin] will take effect.