info_radial_link_controller

info_radial_link_controller is a point entity available in all Source games. It automatically severs node connections that pass through its radius. If it moves, it will restore those connections.

It is useful when parented to large movable objects (physical props like cars), as it will make the AI circumvent the parent object rather than bump into it cluelessly.

Its radius should therefore be set to correspond with the parent object's dimensions.

For example, this setup was used in Half-Life 2: Episode One (where the entity was first added), parented to various cars in the Lowlife chapter.

In code, it is represented by theCAI_RadialLinkControllerclass, defined in theai_dynamiclink.cppfile.

Keyvalues

Radius (radius) <float>

Range at which node connections will be affected.

Name (targetname) <string>

The name that other entities refer to this entity by, via Inputs/Outputs or other keyvalues (e.g. parentname or target).
Also displayed in Hammer's 2D views and Entity Report.

See also:  Generic Keyvalues, Inputs and Outputs available to all entities

Parentname:

Parent (parentname) <targetname>

Specifies a movement parent. An entity will maintain its initial offset from its parent. An attachment point can be added to the end of the name, separated by a comma.

Inputs

Parentname:

SetParent <string>

Move with this entity. See Entity Hierarchy (parenting).

SetParentAttachment <string>

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.

SetParentAttachmentMaintainOffset <string>

As above, but without teleporting. The entity retains its position relative to the attachment at the time of the input being received.

ClearParent

Removes this entity from the the movement hierarchy, leaving it free to move independently.