Portal

Portal nodes are used to enable visibility between Rooms.

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 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 occlusion culling, 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 outward 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.

• linked_room

This is a shortcut for setting the linked Room in the name of the Portal (the name is used during conversion).

• points

The points defining the shape of the Portal polygon (which should be convex).

These are defined in 2D, with 0,0 being the origin of the Portal node’s Spatial.global_transform.

Note: These raw points are sanitized for winding order internally.

• portal_margin

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.

• two_way

Portals default to being two way - see through in both directions, however you can make them one way, visible from the source room only.

• bool use_default_margin

In most cases you will want to use the default Portal margin in your portals (this is set in the ).

If you want to override this default, set this value to false, and the local portal_margin will take effect.

Sets individual points. Primarily for use by the editor.