godot/doc/classes/Portal.xml
lawnjelly eb6f98ec55 Portal occlusion culling
Adds support for occlusion culling via rooms and portals.
2021-07-14 11:43:23 +01:00

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XML

<?xml version="1.0" encoding="UTF-8" ?>
<class name="Portal" inherits="Spatial" version="3.4">
<brief_description>
Portal nodes are used to enable visibility between [Room]s.
</brief_description>
<description>
[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.
</description>
<tutorials>
</tutorials>
<methods>
</methods>
<members>
<member name="linked_room" type="NodePath" setter="set_linked_room" getter="get_linked_room" default="NodePath(&quot;&quot;)">
This is a shortcut for setting the linked [Room] in the name of the [Portal] (the name is used during conversion).
</member>
<member name="points" type="PoolVector2Array" setter="set_points" getter="get_points" default="PoolVector2Array( 1, -1, 1, 1, -1, 1, -1, -1 )">
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 [code]global_transform[/code].
[code]Note:[/code] These raw points are sanitized for winding order internally.
</member>
<member name="portal_active" type="bool" setter="set_portal_active" getter="get_portal_active" default="true">
Visibility through [Portal]s can be turned on and off at runtime - this is useful for having closable doors.
</member>
<member name="portal_margin" type="float" setter="set_portal_margin" getter="get_portal_margin" default="1.0">
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.
</member>
<member name="two_way" type="bool" setter="set_two_way" getter="is_two_way" default="true">
Portals default to being two way - see through in both directions, however you can make them one way, visible from the source room only.
</member>
<member name="use_default_margin" type="bool" setter="set_use_default_margin" getter="get_use_default_margin" default="true">
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 [code]portal_margin[/code] will take effect.
</member>
</members>
<constants>
</constants>
</class>