trigger_proximity

trigger_proximity is a brush entity available in all Source games. It measures the distance of an entity within the trigger volume from a given point (and within a given radius). The NearestEntityDistance output will be 0 when the entity is at the center point, and 1 when the entity is at the radius.

In code, it is represented by theCTriggerProximityclass, defined in thetrigger.cppfile.

Note:This entity cannot reliably detect when an entity exits the radius, which makes it only useful for detecting when one entity approaches another. This is due to the NearestEntityDistance output only firing while the entity is inside the radius, and that it sends a parameter of only 0 or 1, depending on if the entity is near the center (0) or at the edge (1). These are the only times that the parameter changes. Use the OnEndTouch output of trigger_multiple instead to detect when the entity moves away.

Tip:The main use of this entity is to detect proximity to a dynamic entity that can rotate, since the detection area is a consistent sphere. Spherical parented triggers are possible, but spherical brushes are not recommended.

Note:This entity does NOT work well in MP maps. It will function, but it will then break all other triggers in the map if you have multiple players in the map. Solo will show all the triggers working correctly though.

Keyvalues

Point to Measure From ([todo internal name (i)]) <targetname>

The name of the target entity, the origin of which is the point to measure another entity's distance from.

Radius to measure within ([todo internal name (i)]) <string>

The radius to which the distance should be mapped. Entities outside the radius will be ignored.

BaseTrigger Expand

Filter Name (filtername) <filter> A filter entity to test potential activators against. Start Disabled (StartDisabled) <boolean> Stay dormant until activated (with theEnableinput).

Flags

BaseTrigger Expand

Everything (not including physics debris) : [64] Clients (Survivors, Special Infected, Tanks ) : [1] Only clients in vehicles : [32] Only clients *not* in vehicles : [512] Disallow Bots (removed since ) : [4096] NPCs (Common Infected, Witches ) : [2] Only player ally NPCs : [16] Only NPCs in vehicles (respects player ally flag) : [2048] Physics Objects (not including physics debris) : [8] Physics debris (include also physics debris) : [1024] Pushables (Passes entities with classname func_pushable) : [4]  Deprecated. Equivalent to using Everything + filter_activator_class that filters func_pushable.

Inputs

BaseTrigger Expand

Toggle Toggles this trigger between enabled and disabled states. Enable Enable trigger Disable Disable trigger TouchTest  (in all games since ) Triggers either the OnTouching or OnNotTouching outputs for whether anything is touching this entity. Bug:Sleeping prop_physics will never fire "OnTouching". Also applies to entities using prop_physics as base.  (tested in: ) StartTouch  (in all games since ) !FGD Behave as if the !caller entity had just entered the trigger volume. Accepts non-physical entities. EndTouch  (in all games since ) !FGD Behave as if !caller had just exited the trigger volume. DisableAndEndTouch  (only in ) Disables this trigger and calls EndTouch on all currently-touching entities.

Outputs

NearestEntityDistance <integer>

Fired continuously when entities are touching the trigger volume.
The output parameter is the distance from the Point to Measure From to the nearest entity that passed the trigger filters.
The distance is mapped to the radius distance, so it will be 0 when the entity is on the point, and 1 when the entity is at the edge of the radius.

BaseTrigger Expand

OnStartTouch Fired when a valid entity starts touching this trigger. !activator is whatever touches the trigger. Bug:Spamming crouch jumps in a trigger can randomly fire OnStartTouch. Confirm:Is it a Multiplayer issue only?   [todo tested in ?] OnStartTouchAll Fired when a valid entity starts touching this trigger, and no other entities are touching it. If there are any other entities touching the trigger when a new one begins to touch, only OnStartTouch will fire. OnEndTouch Fired when a valid entity stops touching this trigger. Warning:This includes entities which are deleted while inside the trigger. In this case !activator will be invalid. Warning:Will also fire if sent Disable input or an entity teleports outside of the trigger area. Warning:OnEndTouch can fire before OnStartTouch under certain circumstances where both are fired on the same tick and each have the same delay. Fix:Add a slight delay to OnEndTouch. Bug:Spamming crouch jump in a trigger can randomly fire OnEndTouch. Confirm:Is it a Multiplayer issue only?   [todo tested in ?] OnEndTouchAll Fired when all valid entities stop touching this trigger. OnTouching  (in all games since ) Fired if something is currently touching this trigger when TouchTest is fired. OnNotTouching  (in all games since ) Fired if nothing is currently touching this trigger when TouchTest is fired.