From Valve Developer Community
logic_relay is a point entity available in all Source games. It is a message forwarder. It can be used to fire many outputs at once from just one input, or, by being disabled, to break an I/O chain. It can also be very helpful for organization and keeping you from having to edit MANY instances of the same outputs, as opposed to just one.
- Entity Scripts
<scriptlist>(New with 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
<string>(New with 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.
- Start Disabled (StartDisabled)
- Stay dormant until activated (probably with the
- 1: Only trigger once
- 2: Allow fast retrigger (otherwise there is a minimum delay of 0.001 seconds)
- Allows the relay to fire the OnTrigger outputs after being disabled.
- Prevents the relay from firing OnTrigger outputs in response to Trigger inputs.
- Trigger the relay, causing its OnTrigger output to fire if it is enabled.
- Toggle the relay between enabled and disabled.
- Cancel any events fired by this relay that are currently pending in the I/O event queue.
- Allows a slow trigger to fire again. (See the second flag)
- Removes this entity and any entities parented to it from the world.
- Functions the same as
Kill, although this entity and any entities parented to it are killed on the same frame, being marginally faster than
- Evaluates a keyvalue/output on this entity. It can be potentially very dangerous, use with care.
<output name> <targetname>:<inputname>:<parameter>:<delay>:<max times to fire, -1 means infinite>
- Fire the
OnUseroutputs; see User Inputs and Outputs.
- Same as a player invoking +use; may not do anything. Can also be invoked by creating an output that does not specify an input.
This input is not included in Valve's FGDs.
<script>(New with 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.
<string>(New with 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 , 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.
<string>(New with Left 4 Dead 2) !FGD
- Execute a VScript function in the scope of the receiving entity.
<coordinates>(New with 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.
<angles>(New with Alien Swarm) !FGD
- Set this entity's angles.
- Fired when the relay is spawned. If the relay is set to only trigger once, it will delete itself after firing this output.
- Fired when the relay is triggered. If the relay is set to only trigger once, it will delete itself after firing this output.
- These Outputs each fire in response to the firing of the like-numbered
FireUser4Input; see User Inputs and Outputs.
OnKilled(Only in the Left 4 Dead series)
- This Output fires when the entity is killed and removed from the game.