RED Portals and Rooms: Difference between revisions

Revision as of 17:53, 15 November 2020

Portal Rendering Basics

Red Faction uses portal rendering to determine what geometry and objects will be visible at any given time and therefore avoid instances where level assets that can't be seen by the player are still being rendered. By determining which geometry and objects are not currently visible, and not rendering those assets, significant performance improvements are achieved.

As a concept, this approach involves separating levels into sectors (referred to as rooms), which are connected to one another by small openings that the engine has been instructed to consider as portals. When the engine determines that a room behind a portal needs to be rendered (based on the player's current camera position and view direction), only the parts of that room that are visible through the portal are rendered, rather than the entire space. As a general practice, portals should be configured in any confined areas (doors, tunnels, windows, etc.) that connect two otherwise separate areas of a level. The use of portals in this way greatly simplifies the engine's task of determining visible areas and objects from any given point of view.

At a technical level, portals allow the engine to use each portal as a viewing frustrum for the area behind the portal.

Visualization

Rooms and portals can be visualized in RED and within the Red Faction game client itself.

Rooms

Door Rooms

Portals

Air Brush Portals

Solid Brush Portals

Portal Brushes

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 At a technical level, portals allow the engine to use each portal as a [https://en.wikipedia.org/wiki/Viewing_frustum viewing frustrum] for the area behind the portal.
+===Visualization===
+Rooms and portals can be visualized in [[RED]] and within the [[Red Faction]] game client itself.
 ==Rooms==
+<!--- [[RED Brushes#Portal Brushes|Portals]] and physical gaps in geometry (ie. 2 air brushes that are not attached to eachother in any way) are both used to separate levels into Rooms. Rooms are used to help the engine determine what it needs to render at any given time for a client, so are very valuable for framerate optimization. Additionally, room definition determines the boundaries of [[RED Objects#Room Effect|Room Effects]], [[RED Objects#EAX Effect|EAX Effects]], and airlocks.
+You can use the [[RED Functionality Overview#View Menu|View Menu]] option '''Show Rooms in Different Colors''' to easily see the individual rooms in your level.--->
 ===Door Rooms===