From Valve Developer Community
Revision as of 23:32, 9 February 2019 by Ficool2 (talk | contribs)

Jump to: navigation, search
Not to be confused with GameUI.
game_ui is a point entity available in all Source games. It redirects important player key presses to a series of outputs, and can be used to make the player control vehicles built in a map. It can be activated with I/O, or by the player looking at it.
Note:You must have one instance of game_ui per player in multiplayer.
To do: What happens if you don't...?
Note:Bots can use this entity and fire its outputs.


FieldOfView <float>
How close to the entity the player's crosshair must be for it to take control. When the player leaves the active zone, they regain control.
  • 1.0 = straight ahead
  • 0.0 = +/- 90 degrees
  • -1.0 = all directions


Name (targetname) <string>
The targetname that other entities refer to this entity by.
Entity Scripts (vscripts) <scriptlist> (in all games since <Left 4 Dead 2>)
Space delimited list of VScript files (without file extension) that are executed after all entities have spawned. The scripts are all executed in the same script scope, later ones overwriting any identical variables and functions.
Script think function (thinkfunction) <string> (in all games since <Left 4 Dead 2>)
Name of a function in this entity's script which will be called automatically every 100 milliseconds (ten times a second) for the duration of the script. It can be used to create timers or to simulate autonomous behavior. The return value (if present) will set the time until the next call.
Note:Try to avoid expensive operations in this function, as it may cause performance problems.


  • Freeze Player - The player cannot move (they can still crouch though)
  • Hide Weapon - Disables all the player's weapons
Note:This will cause the player to go into their reference (T) pose.
  • +Use Deactivates
  • Jump Deactivates


The !activator will gain control upon this input being fired.
The entity will only test FieldOfView if it is active.

Warning: Deactivating an already-inactive game_ui crashes the game!.

To do: Which games is this an issue in? Only tested on <Team Fortress 2>, where it crashes.


Removes this entity from the world.
Removes this entity and its children from the world.
Note:Entities already remove orphaned children upon being removed, but this input removes all children on the same frame, being marginally faster than Kill.
AddOutput <string>
Adds a keyvalue/output to this entity. It can be potentially very dangerous, use with care.
KV Format: <key> <value>
I/O Format: <output name> <targetname>:<inputname>:<parameter>:<delay>:<max times to fire, -1 means infinite>
FireUser1 to FireUser4
Fire the OnUser outputs; see User Inputs and Outputs.
Use  !FGD
Same as a player invoking +use; may not do anything depending on the entity. Can also be invoked by firing an output that does not specify an input.
RunScriptFile <script> (in all games since <Left 4 Dead 2>)
Execute a VScript file from disk, without file extension. The script contents are merged with the script scope of the receiving entity.
RunScriptCode <string> (in all games since <Left 4 Dead 2>)
Execute a string of VScript source code in the scope of the entity receiving the input. String quotation may be needed when fired via console.
Bug: In <Left 4 Dead 2>, the code is executed in the script scope of the entity that fires the output, not the one receiving the input.
Warning: Never try to pass string parameters to a script function with this input. It will corrupt the VMF structure because of the nested quotation marks, which then must be removed manually with a text editor.
CallScriptFunction <string> (in all games since <Left 4 Dead 2>) !FGD
Execute a VScript function in the scope of the receiving entity.
SetLocalOrigin <coordinates> (in all games since <Alien Swarm>) !FGD
Send this entity to a spot in the map. If the entity is parented to something, it will be offset from the parent by this amount.
SetLocalAngles <angles> (in all games since <Alien Swarm>) !FGD
Set this entity's angles.


The player is always the !activator.

Fired when the entity starts or stops controlling the player's input.
UnpressedMoveLeft (New with Half-Life 2: Episode Two / Source 2007)
Fired on +moveleft/-moveleft
UnpressedMoveRight (New with Half-Life 2: Episode Two / Source 2007)
Fired on +moveright/-moveright
UnpressedForward (New with Half-Life 2: Episode Two / Source 2007)
Fired on +forward/-forward
UnpressedBack (New with Half-Life 2: Episode Two / Source 2007)
Fired on +back/-back
UnpressedAttack (New with Half-Life 2: Episode Two / Source 2007)
Fired on +attack/-attack
UnpressedAttack2 (New with Half-Life 2: Episode Two / Source 2007)
Fired on +attack2/-attack2
XAxis <float>
YAxis <float>
Fired whenever the X/Y axis of the player's input changes. Only useful for analogue gamepad input.
  • -1.0 = +moveleft / +back at 100% speed
  • 0 = no movement in this axis
  • +1.0 = +moveright / +forward at 100% speed
AttackAxis <float>
Attack2Axis <float>
An output that fires whenever the state of the player's "attack" key changes. Only useful for analogue gamepad input.
  • 1.0 = bumper is 100% depressed
  • 0 = bumper is at rest


OnUser1 to OnUser4
These outputs each fire in response to the firing of the like-numbered FireUser1 to FireUser4 Input; see User Inputs and Outputs.
OnKilled  (only in <Left 4 Dead><Left 4 Dead 2>)
This output fires when the entity is killed and removed from the game.