From Valve Developer Community
info_lighting_relative is a point entity available in all Source games. It is used in d1_trainstation_01, inside the train car Gordon encounters G-Man. It can be used on any model entity. Use the !FGD LightingOriginHack keyvalue to set the entity's initial lighting origin and the !FGD SetLightingOriginHack input to set a new lighting origin. This method of lighting most commonly used with prop_dynamic enables you to select a different light origin without affecting the light environment around the model (See Video Demo Below). Great for lighting up trees with many lights or doing manual light correction.
- Lighting Landmark
- Entity at which the reference origin is contained. If empty, the info_lighting_relative's origin will be used.
- The targetname that other entities refer to this entity by.
- 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.
- Removes this entity from the world.
- Removes this entity and all its children from the world.
- 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: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. Note:This input is missing from some games FGD files.
<origin>(New with Alien Swarm) !FGD
- Set this entity's origin in the map. Note:This input is missing from some games FGD files.
<angles>(New with Alien Swarm) !FGD
- Set this entity's angles in the map. Note:This input is missing from some games FGD files.
- Move with this entity. See Entity Hierarchy (parenting).
- Change this entity to attach to a specific attachment point on its parent. The entity will teleport so that the position of its root bone matches that of the attachment. Entities must be parented before being sent this input.
- As above, but without teleporting. The entity retains its position relative to the attachment at the time of the input being received.
- Removes this entity from the the movement hierarchy, leaving it free to move independently.
- These Outputs each fire in response to the firing of the like-numbered
FireUser4Input; see User Inputs and Outputs.
(New with Left 4 Dead)
- This Output fires when the entity is killed and removed from the game.
[https://www.youtube.com/watch?v=JVtIS-Rssjc Video by gtamike_TSGK
[http://gamebanana.com/prefabs/7242 Relative Lighting Tutorial by Bud Doug Lee