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Terminology

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Contributors: Please read the Terminology Style Guide. Also please don't add random UnrealScript variable names to this page, it's not intended for that. (Use the Search instead, please.)

A

Abstract class
a class which can't be added to a map or spawned in game and is thus only useful as a base class. See Class Syntax.
Accessed None
UnrealScript warning message, meaning that code attempted to retrieve or alter data via an invalid object reference (also see Log Warnings)
Active brush
another name for the red builder brush
Actor
object in three-dimensional virtual space
Algorithm
implementation, procedure, protocol, or sequence of rules or instructions, (usually for accomplishing a maths-oriented task) that specify the order and kind of arithmetic operations that are used on specified set of data, though technically, a cooking recipe is an example
Alpha Channel
Information contained within an image file that can be used to determine the intensity of different material properties such as opacity and specularity intensity among other things.
Alpha Map
An Unreal Tournament Map that is being tested by the mapper, and/or a few other, selected people.
Alpha version
unfinished software version, not yet feature-complete; not ready for public release.
Animation
Series of pre-generated, articulated graphic components that convey character motion or behavior, during a scene display, and are called by the animation subsystem in specific game situations
Anti-Aliasing
System of smoothing out jagged edges on the screen. Video card renders at a higher resolution and then tones it down to your current set resolution.
Anisotropic Filtering
System to improve quality of textures rendered at various angles.
Assertions
Code expression that usually evaluates to true or false. Utilized to ensure that components behave properly; typically, checks on execution conditions and performance
Array
Variable containing an ordered set of values of the same type, indexed by an integer
AI
Artificial Intelligence; in game development, AI is a code subsystem that controls the behavior of agents (or Bot (UT)s, see Bot Support), objects, and numerous actors; the AI is responsible for realistic, or, intelligent, behavior of opponents during gameplay
Attribute
synonymous to Property

B

Base class
higher level, generalized class; used to define characteristics common to all its subclasses. ScriptedPawn is the base class for Unreal I monsters, for example.
Beta version
unfinished software version, yet considered feature-complete, that's still in testing stage; not yet ready for public release
Bilinear Filtering
see Bilinear Filtering.
BMP
bitmap file format (with no or lossless compression)
Boolean
value that is either true or false
Bone
An object which describes the relationship of itself to other "bones." Bones usually have vertices attached which move with the bone, thus creating an animation without worrying about the placement of each vertex. See Skeletal Mesh
Bot
A computer-controlled player character
Botplay
The gameplay as specifically related to Bot Support
Brush
piece of geometry that builds the virtual space
BSP
Binary Space Partition; static data structure method used by game programmers to determine correct front-to-back polygon visibility, so that scenes are rendered realistically
BSP hole
building bug, yields unwanted invisible obstacles and players falling into geometry and dying

C

Canvas
the class in the Unreal engine that is responsible for drawing items directly onto a player's display. The most common use of the canvas is in the creation and modification of a HUD.
Casting
see Typecasting
Class
type of an object, an object's class defines how an object is implemented; derived from or instantiated by an object, from which it inherits clearly defined attributes. A class can contain: static data members, objects of another class, pointers and references to types and objects of the same or another class, declarations of another class, member functions, and friend classes. All Classes are listed in the Actor browser.
Client
any linked user (another remote computer terminal, or program, or even another class) of another server, or program, or class is said to be a client of that entity.
Compiler
software that parses a high-level language, and converts source code to a binary executable program, that will run on Windows, Unix, or some operating system.
Constructor
method that is automatically called when an object is created; responsible for initializing this object; see Creating Actors And Objects.
CSG
Constructive Solid Geometry, the general idea behind building geometry in UnrealED.

D

Declaration
code statement that doesn't produce executable code when compiled, but informs the compiler about new variables and functions (and their types, parameters, and so on)
Destructor
method that is automatically called when an object is destroyed; responsible for releasing resources (memory, sockets, other objects) used by this object; see destroying objects
DLL
Dynamic Link Library, file containing native executable code that is bound to another application (or UnrealScript) at runtime
DXT
some sort of texture compression mojo. See texture format.
Dynamics
Effects in the map that the map designer put in to make the map more pleasing to the eyes and ears. Examples are Movers, Emitters, and Sounds.

E

Emitter
an Actor responsible for creating a particle effect; there are two emitter classes in UT2003: Emitter and xEmitter
Engine
the underlying code framework which makes a complex computer program run.
Enumeration
ordered set of numeric constants whose values are automatically assigned during compilation (declared with the enum keyword)
Environment mapping
dynamic UV mapping of a skin on a mesh, depending on the viewer's relative position, producing a mirror-like effect.
Event
(1) an actor's or trigger's reaction to something, broadcast to actors with matching tags; (2) UnrealScript function called from native code.

F

Face
see Polygon
FinalBlend
a texture Modifier
Float
numerical value capable of storing numbers with digits after the decimal point (like 3.142)
Forward kinematics (FK)
A term used in skeletal animation, indicating that motion in a skeletal hierarchy (a set of connected bones) is transferred down the hierarchy. Example: rotation applied to a shoulder joint results in rotation of the bones below that joint in the skeletal chain : upper arm, forearm, hands, fingers or claws, etc. See also Inverse kinematics (IK).
FOV
Field Of Vision (or: Field Of View)
Function
piece of code with a defined entry point and one or more exit points
Function call
request for an object to carry out one of its operations. Code command within a program that jumps to a different portion of the code and returns to the statement following the call after executing that code (and may return a data value to it). The function return can be a value, a reference, or a pointer.
Function overriding
see Overriding
Function prototype
see Prototype

G

G16
16 bit grayscale texture. See texture format
Gameplay
the playability of a game or an element of a game or map; it's relative value in terms of play
Gametype
a way to implement a mod; specifies basic rules for playing the game (e.g. CTF: get enemy flag and touch your own with it); can be further modified through mutators
Garbage collection
automatic destruction of unreferenced objects (as in Java, Perl or UnrealScript)
Gimbal lock
occurs when rotations in successive axes make further rotations either impossible or produce undesired results.
Gibs
Body parts that fly everywhere when you blow somebody up.
Gold Version
Version released to the public after the Alpha and Beta versions.

H

Hidden variable
a variable defined in a class but not accessible in UnrealEd's Actor Properties Window. This is done with the variable syntax var instead of var().
Hierarchy
an ordering of things (such as objects, classes, people) in a tree-like structure, where things descend or depend on their superiors. Examples: a family tree, the military chain of command. Superseding values affect preceding values, but not vice versa.
HOM
Hall Of Mirrors effect, a rendering bug
HUD
Heads-Up Display, rendered on top of the in-game 3D viewport and displaying in-game data like frags, weapons, ammo and scores

I

Implementation
program code structure that accomplishes some task or sequence of functions (see also Interface)
Inheritance
relationship among classes wherein one class shares the structure and/or behavior defined in one or more other superclasses
Instantiation
creation of an object from a class, each object having a copy of its own (non-static) data members
Instigator
a Pawn which is considered responsible for the damage done by one actor to another; an Actor class property; often used for the InstigatedBy or EventInstigator parameters of Trigger() and TakeDamage() functions
Integer
numerical value, a whole number without decimals (like 10)
Interface
user's or client's perception of an object; object-oriented data abstraction is to provide a clean and efficient interface that allows the user to access the underlying implementation
Inverse kinematics (IK)
A term used in skeletal animation, indicating that motion in a skeletal hierarchy (a set of connected bones) is transferred up the hierarchy. Example: Positioning a hand bone at the end of a skeletal chain results in joints further up the chain (e.g., forearm and upper arm) being relocated as needed. See also Forward kinematics (FK).
Iterator
special function that allows iteration over all or a given subset of all objects, using a foreach loop

J

JumpSpot
a NavigationPoint actor indicating a good place for bots to jump to, not from. Also indicates a good point for translocation, double-jump, impact-jump, etc.

K

KillZ?
a Level Properties setting of the lowest altitude that a Pawn can exist. Lower than this altitude, the Pawn is killed. See also StallZ.

L

Lighting
A combination of the lights in the levels, and the light-maps that are overlayed onto walls, giving the impression of lights on those walls.
Linked List
List consisting of objects where each item has a reference (link) to the next one.
LOD
Level Of Detail. Allows high-end machines to display fancy detail (eg weather effects) and low-end machines to just show the essentials. Also allows details to be skipped at farther distances, improving performance. (which allows more details to be shown at closer distances) See, for example, Chain Of Events When Spawning Actors.
Log?
text file which the game writes as it executes.

M

Map Flow
Map layout design that promotes smooth, fast and exciting gameplay
Masked
color blending type; makes part of a Texture (UT) transparent (see color blending)
Material
rectangular image (bitmap) that can be applied to brush surfaces and meshes or directly drawn on a canvas; also see texture
Mesh
three-dimensional representation of an Actor in virtual space (like weapons, pickups, players)
Method
function (piece of code) that deals with objects of a given class; defined by the object's class
Mod
short for modification; modification of a game can add new rules or content and in UnrealEngine games (like Unreal or Unreal Tournament) a modification can be implemented as a Mutator, a gametype, a total conversion, a player model, a VoicePack?, an AnnouncerPack? and a few other ways
Modulated
color blending type; mid-gray is transparent, black and white are opaque (see color blending)
Mover
movable Brush (for doors, elevators and visual effects)
Mutator
a way to implement a mod in UnrealEngine games; mutators usually just change a certain aspect of the game, but there are also mutators with large scale modifications (e.g. weapon mods, competitive mods); mutators are stackable with other mutators to combine their modifications
MyLevel
a special name for a package. Using this tells UnrealEd to embed a resource in the current map file.

N

Name
unique specifier for an object or class (or something else) in UnrealScript; unlike strings, can't be modified like a string value and may not contain anything except letters, numbers and underscores
Native code
code that can be interpreted by a computer's processor without any intermediate steps. In Unreal, this is C++ code in DLL files.
Newbie
a person that's new to and hence unexperienced in something.
N00b
same as Newbie, but is contemptuous (is that a good word for them?) about being that. They are sometimes [poseurs].
Node
the polys that are seen in Zone/Portal view. They correspond to surface polygons split by BSP cuts. See polygon and node count.
Node count
a measure of how much rendering work the engine has to perform to display a view of a map. Also the total number of nodes in the name.
Null
Texture(s) that is missing or can not be found. These null textures are given a default texture used by the engine (The green bubbly texture).

O

Obfuscation
Creating code that works but is difficult to understand or work out what it actually does.
Object
abstraction that typically is assigned clearly specified characteristics; in other words, a chunk of data with a certain class associated to it; the class describes the data structure and contains the code that deals with objects of that class
OCD
Object Collision Detection
OOP
Object Oriented Programming
Overloading (a function)
redeclaring and reimplementing a function with the same name as an existing function, but a distinguishable set of parameters (like having two versions of a function, one of them working for float parameters, one of them for integer parameters)
Overriding (a method)
redeclaring and reimplementing a method in a subclass
Overwriting (a method)
see Overriding (a method)
Owner
Constant Actor declared in the Actor class, specifies who or what owns this object. Use native SetOwner( actor NewOwner ); to set the owner.

P

Package
a file containing resources for Unreal engine games (like code, decorations, sound, music, maps, or all of it)
Pathing or Bot Pathing
supporting bot navigation of a level (see Bot Support)
Palette
look-up table of colors used in a bitmap
Pawn
The parent class of all creatures and players in Unreal which are capable of high-level AI and player controls.
PCX
bitmap file format (with no or lossless compression)
Pivot
point about which a brush is rotated or scaled.
Pointer
variable that "points to" an object's memory location; in UnrealScript, all object variables are (typed) pointers, but there's also an unspecific pointer variable type that serves as a placeholder for C++ pointers in native code
Polycount
either number of polys currently drawn on screen by the engine, or the total number of polygons in the map.
Polygon
two-dimensional, flat, closed shape in three-dimensional space, like a brush surface. Currently Unreal Tournament only supports convex polygons.
Prefab
A collection of Actors, such as CSG brushes and/or lights that can be copied and used over and over again in a map. ( Useful for distributing map parts without sacrificing storage space since a .t3d (Unreal Text) file is much smaller than a .ut2 file )
Private (method or property)
not accessible from outside the class this method or property has been declared in (see Public (method or property))
Probe function
A function that can be enabled or disabled using the Enable and Disable methods. These functions are usually defined as "events" and are called by native engine code.
Property
individual item of an object's data; defined by the object's class
Prototype
number, order and types of function parameters
Projector
UT2003's replacement for the deprecated Decal class. Allows for projected shadows (ShadowProjector class) and other neat stuff.
Public (method or property)
accessible from outside the class this method or property has been declared in (see Private (method or property))

Q

Quad
a single grid element of terrain.
Quaternion
mathematical entity similar to a complex number. These can be used to represent 3D rotations in a way that eliminates the gimbal lock problem with non-l33t rotational matrices; popular with game programmers for this very reason

R

Ray tracing
Calculating the lighting in a level by tracing exactly where the light goes.
RBB
red builder brush
Rendering
subsystem that actually produces the visible scene that is displayed on the computer terminal for players to yell at; consumes the majority of CPU computing capacity
Replication
generic term for sending game-relevant data back and forth between a network server and its clients
RGB8
texture format with three channels (red, green, blue) and 8 bits per channel
RGBA8
texture format with four channels (red, green, blue, alpha) and 8 bits per channel

S

Shader
SHAS
"Sudden Heart Attack Syndrome". Dying for no apparent reason. Sudden cratering is usually caused by BSP holes (see 'BSP hole').
Sheet
a brush which does not enclose a 3D volume, usually because it's a single polygon.
Simulation
generic term for simulation or prediction (not authoritative) of game behaviour on network clients
Skeletal animation
mesh animation by having vertices attached to interlinked bones; see Animation
Skin
set of textures that are applied to a mesh (for instance, a Bot (UT), a player or a decoration)
Sky box
see page
Solidity
see page
Source (code)
original high-level computer language code, like C++ or Java, that is compiled into an executable program
Spawn
UnrealScript command for creating a new Actor
Spawndeath
an error condition during map Playtesting where the player character repeatedly dies, as if automatically suiciding.
StallZ
a Level Properties setting of the highest altitude a flying Vehicle can fly before it's thrust power is deactivated. See also KillZ?.
State
a concept in UnrealScript that allows actors to execute different code in different circumstances. For example, a Bot can be 'Fleeing', 'Attacking', etc. See State and also InitialState
State code
code that is outside of functions in a state block
Static Mesh
see page.
Structure
ordered arrangement of typed data items; similar to a class in UnrealScript, but can't be referenced (only copied) and doesn't have methods
String
value of text; for instance, a message somebody typed in
Subclass
class derived from another class (its base class, or superclass); inherits properties and methods from the superclass unless they're expressly overwritten
Surface
see page.
Syntax
the rule of arranging and ordering commands to form a code. UnrealScript grammar, if you will; see class syntax and function syntax

T

Texel
Texture pixel (as opposed to screen pixel)
Text Parsing
the act of using a routine or function of some sort to change symbols in a string variable to reflect the values of certain variables, e.g. replacing "%k" in a death message with the killer's name; see Message Placeholder
Texture
rectangular image (bitmap) that can be applied to brush surfaces and meshes or directly drawn on a canvas; special type of material
Total conversion
mod attempting to totally change the underlying game into a different game by providing all-new content (game types, user interface, weapons, maps, models, menus)
Trace
follows a straight line through the world, usually until it hits solid geometry. Usually used to determine where bullets hit.
Translucent
color blending type; black is transparent, white is opaque (see color blending)
Trigger
An actor in a level which, when touched, will activate some effect, or other event.
Typecasting
converting one type of variable to another (e.g. Float to Integer)

U

UC file
An UnrealScript source code file (Unreal Class), readable in any plain-text editor.
UAX
UT's and UT2003's sounds format.
Ucc
UnrealScript execution environment, ucc.exe in the System subdirectory
UMOD
Unreal Mod installer
UMX
UT's music format.
Unlit
(Texture (UT)) rendered without any lighting applied to it; yields a bright, uniform appearance
USA file
In Unreal 1, Unreal 2, and OldSkool for UT, a file created to save data from a singleplayer game in progress.
UT2MOD
UT2003's UMOD format
UU
Unreal units, used to measure and specify lengths within the engine's virtual space
UV mapping
two-dimensional application and alignment of a skin on a mesh

V

Variable
memory location with a symbolic name where a program can store information for future retrieval
Vertex
point in (normally two- or three-dimensional) space; point where polygon edges meet
Vertex animation
mesh animation by playing a set of different, fixed vertex arrangements (like stop-motion animation in movies); see Animation
Viewport
Window in UnrealEd which shows one view of the map that is loaded; a class in UnrealScript that represents the local player

W

Wiki
collaborative, open project on the web, gathering knowledge on a certain topic
WarpZone
special kind of zone. A WarpZone's portal renders what can be seen from the destination portal, and also teleports players and objects which enter it to the destination portal.

Z

Z-axis
The third axis in a 3D co-ordinate system. In FPS games, this also refers to things (architectural detail, enemies, etc) being above or below the player.
Zone
Portion of a map's space that is sectioned off, either to achieve special effects (gravity, water, etc.) or for engine optimization
Zone portal
Type of polygon (usually built with a sheet brush) which tells the engine where zone boundaries lie.

Related Topics

Some other pages that may help:

Discussion

Sweavo: I would have thought UScript's semantics would be better thought of as references rather than pointers, since it's not meaningful to increment a reference, whereas incrementing a pointer has some meaning, albeit ill-defined...? Also since non-native functions are executed in bytecode (aren't they?) then actual pointers (in the hardware sense) are not passed around in executing unrealscript are they? I imagined array indices.

IceCreamYou: I took the liberty of adding a link to my own Key Terms page... I can't guarantee there aren't a few errors, but it is a very complete list.


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