func_lookdoor
func_lookdoor
is a brush entity available in the Half-Life 2 series. It's a door that moves, either when looked by a targeted object or when a target object comes near the door. Behavior can be either based on viewing direction or proximity alone, or on a combination of both.

SetPosition
input and Start Position keyvalue do not perform any bounds checking, so values less than 0 and greater than 1 can be used. Negative values will move in the opposite direction to the movement direction, and values greater than 1 will move it in multiples of the set Move Distance. Moving past the opened/closed position does not trigger the OnFullyOpen
and OnFullyClosed
outputs.
func_movelinear
, momentary_door
, func_lookdoor
, func_water_analog
. A func_door
can be used as a workaround.Code Fix: See here for a code fix.


move_rope
or keyframe_rope
will cause the entities to disappear. Clarification required if the rope entities are deleted or are simply not rendered.This entity is also in the code for . Its functionality is not guaranteed.
In code, it is represented by class
CLookDoor
, defined in look_door.cpp
.
Contents
Flags
!FGDFuncMoveLinear:
- 8: Not Solid

LookDoor:
- 8192: LookDoor Threshold
- 16384: LookDoor Invert - Make the door behave oppositely. Player has to be outside Proximity Distance, and not looking at the door within Field of View.
- 32768: LookDoor From Open
Keyvalues
- Target (target)
<targetname>
!FGD - Thing (probably a
player
) that we will check for LOS to the door. - Proximity Distance (ProximityDistance)
<float>
- If non-zero, how close target must be for door to move.
- Proximity Offset (ProximityOffset)
<float>
- Offset from the target object.
- Field of View (FieldOfView)
<float>
- If non-zero, how far away from the door the target can look while still triggering it.
FuncMoveLinear:
- Move Direction (Pitch Yaw Roll) (movedir)
<angle>
- The direction the entity will move in.
- Start Position (startposition)
<float>
- Position of brush when spawned, where 0 is the starting position and 1 is starting position + (move direction * move distance).
- Speed (speed)
<integer>
- The speed that the brush moves, in inches per second.
- Move Distance (movedistance)
<float>
- The distance from the starting point that the brush should move, in inches.
- Block Damage (blockdamage)
<float>
- The amount of damage to do to any entity that blocks the brushes, per frame.

trigger_teleport
using noclip
, though it will have effect again if the the player goes through a trigger_teleport without noclip.- Sound played when the brush starts moving. (startsound)
<sound>
- The sound to play when the brush starts moving.
- Sound played when the brush stops moving. (stopsound)
<sound>
- The sound to play when the brush stops moving.
Visible Brush:
- Minimum Light (_minlight)
<float>
- Minimum amount of light to hit this brush. 0 is none, 1 is normal, and 2 is doubled.
- Damage Filter Name (damagefilter)
<targetname>
- When this entity receives damage, it will filter by this entity.
- Render Mode (rendermode)
<choices>
- Set a non-standard rendering mode on this entity.
ᅠ
ᅠ
- Render FX (renderfx)
<choices>
- Preset pattern of appearance effects.
ᅠ
ᅠ
- To do: 18-21, 25
- Render FX / Transparency (0 - 255) (renderamt)
<integer>
- Transparency amount, requires a Render Mode other than Normal. 0 is invisible, 255 is fully visible.
- Render Color (R G B) (rendercolor)
<color255>
- Color tint.
- Shadow Cast Distance (shadowcastdist)
<integer>
!FGD - Sets how far the entity casts dynamic shadows. 0 means default distance from the
shadow_control
entity. - Shadows (vrad_brush_cast_shadows)
<integer>
!FGD - Determines if this entity will cast lightmap shadows.
- 0: No shadows
- 1: Cast shadows
- Disable Shadows (disableshadows)
<boolean>
- Prevent the entity from creating cheap render-to-texture shadows. Does not affect shadow mapping.
- Disable Receiving Shadows (disablereceiveshadows)
<boolean>
- Prevent the entity from receiving shadows on itself.
- Texture Frame (texframeindex)
<integer>
!FGD - The frame number for any animated textures on this entity.
Base:
- Classname
(classname)
<string>
- The classname defines the type of entity. Classnames can be changed using
AddOutput
, which will influence how the engine deals with the entity in certain circumstances. - Name
(targetname)
<string>
- The name that other entities refer to this entity by.
- Global Entity Name
(globalname)
<string>
- Name by which this entity is linked to another entity in a different map. When the player transitions to a new map, entities in the new map with globalnames matching entities in the previous map will have the previous map's state copied over their state.
- 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. Every entity can be parented, even point entities. Entities which are parented will be forced to transition to the next map, such as from a
trigger_transition
. Some entities which aren't intended to be parented may not function correctly.phys_constraint
can be used as a workaround to parenting. - Origin (X Y Z)
(origin)
<coordinates>
- The position of this entity's center in the world. Rotating entities typically rotate around their origin.
- Pitch Yaw Roll (X Y Z)
(angles)
<angle>
- This entity's orientation in the world. Pitch is rotation around the Y axis, yaw is the rotation around the Z axis, roll is the rotation around the X axis.
Note: This works on brush entities, although Hammer doesn't show the new angles.
- Flags
(spawnflags)
<integer>
- Toggles features of an entity, its specific number is determined by the combination of flags added.
- Response Contexts
(ResponseContext)
<string>
- Pre-defined response system contexts for this entity. Format is
key:value,key:value,...
. Contexts may be filtered. - Effects
(effects)
<integer>
!FGD - Combination of effect flags to use.
- Local Time
(ltime)
<float>
!FGD - The local time of the entity, independent of the global clock. Used mainly for physics calculations.
- Next Think
(nextthink)
<float>
!FGD - Amount of time before the entity thinks again.
- Hammer ID
(hammerid)
<integer>
!FGD - The entity's Hammer ID. Mainly used by plugins and debugging commands, such as
ent_keyvalue
. Can be manually assigned with the "hammerid" or "id" keyvalue. Entities spawned at run-time are not assigned any Hammer ID.
Inputs
InvertOn
- Enabled inverted behavior.
InvertOff
- Turn door behavior back to the normal method.
FuncMoveLinear:
Open
- Move the brush to the end position (starting position + (move direction * move distance)).
Close
- Move the brush to the starting position.
SetPosition
<float>
- Move the brush to a specific position, where 0 is the starting position and 1 is the starting position + (move direction * move distance).
SetSpeed
<float>
- Set the speed and update immediately.
Visible Brush:
Alpha
<integer>
- Sets the entity's transparency to a number from 0 (invisible) to 255 (fully visible). Requires the entity to have its Render Mode (rendermode) set to a number other than
0
. AlternativeSorting
<boolean>
- Swaps the rendering order of the entity. Used to attempt to fix sorting problems when rendering, for example an object rendering in front of translucent materials.
Color
<color255>
- Sets an RGB color for the entity.
SetDamageFilter
<targetname>
- Sets a filter for this entity for when it receives damage.
EnableDamageForces
- Allows the entity to be pushed by damage done to it (usually force amount correlates with the damage done).
DisableDamageForces
- Prevents the entity from being pushed by damage done to it.
EnableShadow
- Allows the entity to draw a render target shadow.
DisableShadow
- Prevents the entity from drawing a render target shadow.
Base:
Kill
- Removes this entity and any entities parented to it from the world.
KillHierarchy
- Functions the same as
Kill
, although this entity and any entities parented to it are killed on the same frame, being marginally faster thanKill
. 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.
AddOutput
<string>
- Evaluates a keyvalue/output on this entity.
Format:<key> <value>
Format:<output name> <targetname>:<inputname>:<parameter>:<delay>:<max times to fire, -1 means infinite>
FireUser1
toFireUser4
- Fire the
OnUser
outputs; see User Inputs and Outputs. Use
!FGD- 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. DispatchEffect
<string>
(removed in) !FGD
- Dispatches a special effect from the entity's origin. Removed and replaced entirely by the particle system since
.
DispatchResponse
<string>
!FGD- Dispatches a response to the entity. See Response and Concept.
AddContext
<string>
- Adds to the entity's list of response contexts. Format is
<key>:<value>
. RemoveContext
<string>
- Remove a context from this entity's list. The name should match the key of an existing context.
ClearContext
<string>
- Removes all contexts from this entity's list.
Outputs
FuncMoveLinear:
OnFullyOpen
- Fired when the brush reaches the end position (starting position + (move direction * move distance)).
OnFullyClosed
- Fired when the brush reaches the starting position.
Base:
OnUser1
toOnUser4
- These outputs each fire in response to the firing of the like-numbered
FireUser1
toFireUser4
Input; see User Inputs and Outputs.