Editing Linked portal (section)

==Terminology==
Linked portals have their own specific sub-set of terminology used to describe certain aspects and behaviors.

===Sector portal plane===
Unlike the basic portal types, which were rendered and could cover height variances (much like the doom sky), linked portals form an actual map structure. The '''Portal Plane''' refers to an X/Y plane that bisects the sector(s) that contain the portal. The z-position of the portal is fixed, and should be the same height on both sides of the linked portal.

===Linedef portal plane===
There are also line-to-line portals, whose plane is vertical. They need to be placed on 2-sided linedefs with a buffer sector behind them. The buffer sector will never be seen in the game, but it's needed to provide a safe space behind the portal linedef for any actor to be able to pass through without being blocked by stray BSP partition lines which may appear in the void, were it not for a buffer sector.

===Beyond the Plane===
Map architecture is said to be beyond the portal plane when its vertical height is equal to or beyond the portal height--that is, at or above a ceiling portal plane or at or below a floor portal plane. When map architecture is beyond a portal plane, the portal will display at the height of the plane.

===Inside the plane===
Map architecture is said to be inside the portal plane when its vertical height is not beyond the portal plane--that is, below a ceiling portal or above a floor portal. Any architecture that is inside the portal plane will render normally and will obscure rendering of the portal.