UnrealEd

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UnrealEd

UnrealEd 3.0 viewing the Unreal Tournament 2004 map "Facing Worlds 3".
Developer:	?
Latest release:	3.0 / ?
OS:	?
Use:	level editor
License:	?
Website:	?

UnrealEd (UEd for short) is the level editor used to create levels for Unreal. It can also be used for other games in the Unreal series, and games based on the Unreal engine, such as Deus Ex, although it has changed along with the engine for later games. Non-Unreal games use their own version of basically the same program. One of the first companies to do this with first person shooters, all Unreal games on the PC had the level editor included for free, and some third party Unreal engine games did the same with an edited and specialized version. This extended the longevity of the games. Amateur level designers could now create their own levels for the game, providing a near endless amount of additional content for the game. In addition, the built-in scripting language called UnrealScript allowed for editors to customize game content.

UnrealEd has a customizable user interface, but the most common is the quad viewports with the top view in the top left, then, moving clockwise, the front view, the side view, and the perspective view. It has a row of buttons along the top pertaining to various options such as save, open, and rebuild, and a series of buttons to the left of the viewports which access editing functions.

1 Versions
2 Basic premise
3 Building designers adopt UnrealEd
4 External links

[edit] Versions

The logo of the latest version of UnrealEd

With the various Unreal games, UnrealEd itself has seen many different versions. Unreal shipped with UnrealEd 1.0, which displayed most of the editing tools on a single large left bar adjacent to the four viewports. This version was extremely buggy, particularly while rebuilding maps.

Unreal Tournament also shipped with UnrealEd 1.0, and UnrealEd 2.0 being added in a later game patch. The editor underwent a major visual change from the previously colourful buttons to a more subdued green scheme. New tools and features were added (such as search capabilities and a new 2D Shape Editor), and it also underwent a significant stability upgrade, and though the editor still had its share of strange crashes, it wasn't nearly as particular as UEd 1.0.

Bundled with Unreal Tournament 2003 was UnrealEd 3.0, which further increased stability. It maintained the green colours, and looks virtually identical to UEd 2.0. The editor added a static mesh browser to support static meshes (known as "hardware brushes" during development), and combined the various browsers into a single browser with tabs to switch between textures, meshes, actors, etc.. This is the current version of UnrealEd.

Future versions of UnrealEd will be fully backwards compatible with content developed under previous versions.

[edit] Basic premise

UnrealEd operates on the concept of brushes. Brushes can be primitive shapes (such as cubes, spheres & cones), pre-defined shapes (such as staircases), or custom shapes (such as prisms and other Polyhedrons). Using CSG operations, complex rooms and objects can be created by adding, subtracting and intersecting brushes to and from one another. Additive brushes can be solids, semisolids or nonsolids.

UnrealEd treats the world as a giant mass. In order to create space, brushes are subtracted from the mass, thereby hollowing out space to walk in. Conversely, the addition of mass creates solid space within the hollowed space. A level is built with a mixture of subtracted and added brushes. The solid, semisolid, or nonsolid denotation of an added brush imbues distinct qualities to the brush: levels may then be created that have complex features and properties. Brushes may also intersect or deintersect, along with being added or subtracted from the 3D virtual space.

In addition, brushes may be movable or special brushes: such a denotation gives game designers, level designers, and level editors the ability to create moving objects within a game. These special types of brushes may be used to create waterfalls, elevators, flying carpets, doors, drawbridges, and many other types of dynamic objects. Zones can be denoted within the various brushes -- after the brush has "sculpted" an area of space within the virtual 3D environment (or level) -- effectively creating wet zones, sky zones, dry zones, or fog zones. In this way, lakes or pools can be created, interiors of buildings or exterior terrain and landscapes. Day or night may be created, through the use of "skyboxes" and other tools in the editor. Weather may be assigned to various levels or zones, allowing such features as snow, rain, or clear weather.

The basic process of CSG operations within UnrealEd is markedly different from other computer game editors that treat the world as a giant space, such as Quake and Quake 2 game level editors. In those and similar game editors, brushes are initially added to the vacant space within the game's 3D environment in order to create virtual terrain and architecture within the level currently being edited. Both subtractive-based computer game editors (such as UnrealEd) or additive-based computer game editors (such as Qoole) may each produce stunning 3D computer graphics for the gameplayer. Yet, each type of editor functions in nearly diametrically-opposed manners. Each type of level editor has its own advantages and disadvantages. The subtractive-based computer game editor, such as UnrealEd, was developed after the additive-based computer game editor, such as Qoole -- or earlier manifestations of such level editors.

In UnrealEd, brushes are used to compile a level into a BSP Tree for rendering and collision detection. Unfortunately, as levels become more complicated they are prone to BSP errors, resulting in visual and collision anomalies. There are several types of BSP errors: BSP holes and hall of mirrors are two common forms. BSP errors can be very difficult to correct. This is partially why the use of Static Meshes was introduced in the Unreal 2 Engine.

Static Meshes are prerendered geometry, created in software such as Maya or 3D Studio Max, that can be imported and positioned within levels. Although a level's foundation and basic layout is still built using brushes, Static Meshes can be used to create complex, intricate architecture that brushes are too coarse to emulate. Because Static Meshes are loaded into memory only once, even if used multiple times throughout a level, they are a more efficient way of using computer resources. Along with the fact that they can be considered as prefabs, Unreal Tournament 2007 will feature static meshes almost exclusively.

[edit] Building designers adopt UnrealEd

In an effort to provide realtime walkthroughs of their proposed buildings, with gravity and impact detection, building designers have begun to build models inside Unrealed to test out their ideas. By allowing the public to pretest a building, a better result can evolve prior to construction. One problem persists however, which is the conversion of element sizes from design programs such as Autocad and 3DSmax into UnrealEd.