path_corner is a point entity available in all Source games.
- A path_corner is a corner in a path, either for a func_train or an NPC. path_corners can be chained together to form complex routes. To create a path_corner chain simply shift+drag an existing path_corner. The values will automatically be filled in. To manually make a chain (or link one up in a circle), edit the Next stop target property.
- A path_corner_crash is identical to a path_corner, but can be enabled and disabled for a crash point; when an NPC is searching for a crash point, it will not search for generic path_corners
- The path_corner entity is !FGD for base.fgd, so it only will appear in Hammer for Half-Life 2
A path_corner can be a destination for an NPC. When told to, NPCs will stop other movement and walk steadily towards a path_corner. It is entirely scripted behavior. Note that the Train Speed and wait values do not affect NPCs.
To make an NPC move to a path_corner edit the Target Path Corner keyvalue, either in Hammer or through the I/O system. Alternatively, an NPC can be made to follow a path_corner chain by using the aiscripted_schedule or scripted_sequence entities.
- See also Assaults for an alternative way to create NPC routes without using path_corner.
Limitations and bugs
- A path_corner (or the first path_corner on a chain) must be within 576 units for NPCs to find it.
- See the apc_on_path and the npc_scanner_on_path prefabs for examples on usage.
- Download Example (VMF)
Note that the example map does not have any info_nodes. They are not needed to have an NPC follow a path.
- 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.
- <target_destination> Next stop target
- <float> Wait here (secs)
- <float> New train speed—Leave at zero to leave path follower's speed the same
- 1 : Wait for retrigger
- 2 : Teleport to THIS path_corner
- 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.
- <target_destination> Set target path_corner
- 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.
- Fires when a path follower passes this point. (activator is the train)