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keyframe_rope is a point entity available in all Source games. It is a node entity that marks a point in a rope. Typically, the first node in the rope is a move_rope entity, followed by 1 or more keyframe_ropes. However, the two are identical in code and freely interchangeable.

Tip.png Tip: Holding Shift while moving a properly named keyframe_rope will create a new keyframe_rope entity that is automatically connected to the previous keyframe. Also, deleting a keyframe_rope within a connected series will update the other entities to re-connect to the next entity in the series.


Position Interpolator <choices> !FGD
Curve Type. Currently only type 2 (Rope) is fully supported.
  • 0 : Linear
  • 1 : Catmull-Rom Spline
  • 2 : Rope
Note.png Note: This is only in the FGD for move_rope, but is functional on both entities.
UseWind <boolean> (in all games since Alien Swarm) !FGD
When set to yes, the rope sways with the settings specified in the env_wind entity. Replaces "Disable Wind" in games post Alien Swarm.


Name (targetname) <string>
The targetname that other entities refer to this entity by.
Entity Scripts (vscripts) <scriptlist> (in all games since 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 (thinkfunction) <string> (in all games since 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.png Note: Try to avoid expensive operations in this function, as it may cause performance problems.


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.


Next KeyFrame <targetname>
Name of the next keyframe along this keyframe path.
Speed (units per second) <integer>
KeyFrame moving speed.


Slack <integer>
How much extra length the rope has (by default it has the length between its two endpoints in the editor).
Type <choices>
Rope type.
  • 0 : Rope
  • 1 : Semi-rigid
  • 2 : Rigid
Subdivision <integer>
Number of subdivisions between each rope segment. Maximum value is 8. Higher values make smoother ropes, but are slower to render.
Barbed <boolean>
Test effect that makes the rope look sharper and more barbed.
Width (1-64) <string>
Width of the rope. Decimal values lower than 1 may also be used.
Texture Scale <string>
This changes the texture resolution. The default resolution is 4 pixels per inch. Larger values stretch the texture and smaller values scrunch it up.
Collide with world <boolean>
If set, the rope collides with world. Ropes never collide with anything else.
Start Dangling <boolean>
If set, the rope starts out detached from its target endpoint.
Breakable <boolean>
If set, the rope can be detached from either endpoint when shot.
Note.png Note: If collide with world is set, the rope will not appear to break if the endpoint touches world geometry. This includes touching vertices and edges of brushes as well as being placed inside them.
Rope Material <material>
The material to use when rendering the rope.
Note.png Note: Source will not render ropes using the cable/chain.vmt material.
Disable Wind <boolean>
If set, the rope will no longer act as though it's being affected by wind.


Minimum DX Level (mindxlevel) <choices>
The entity will not exist if the engine is running outside the given range of DirectX Versions. Replaced by SystemLevelChoice from Left 4 Dead Left 4 Dead onwards.
Warning.png Warning: If these are used, the object may break when the user switches their DirectX settings.
Maximum DX Level (maxdxlevel) <choices>



  • 1 : Auto Resize
Allows the rope to "stretch" as the entity moves.



Removes this entity from the world.
Removes this entity and its children from the world.
Note.png Note: Entities already remove orphaned children upon being removed, but this input removes all children on the same frame, being marginally faster than Kill.
AddOutput <string>
Adds a keyvalue/output to this entity. It can be potentially very dangerous, use with care.
KV Format: <key> <value>
I/O Format: <output name> <targetname>:<inputname>:<parameter>:<delay>:<max times to fire, -1 means infinite>
FireUser1 to FireUser4
Fire the OnUser outputs; see User Inputs and Outputs.
Use  !FGD
Same as a player invoking +use; may not do anything depending on the entity. Can also be invoked by firing an output that does not specify an input.
RunScriptFile <script> (in all games since 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.
RunScriptCode <string> (in all games since 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.png Bug: In Left 4 Dead 2, the code is executed in the script scope of the entity that fires the output, not the one receiving the input.
Warning.png 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.
CallScriptFunction <string> (in all games since Left 4 Dead 2) !FGD
Execute a VScript function in the scope of the receiving entity.
SetLocalOrigin <coordinates> (in all games since 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.
SetLocalAngles <angles> (in all games since Alien Swarm) !FGD
Set this entity's angles.


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


SetScrollSpeed <float>
Set the speed at which the texture scrolls.
SetForce <string>
Apply a force instantaneously to the rope. The parameter should be a vector containing the force to be applied (X Y Z).
Break the rope, if it's marked to do so.



OnUser1 to OnUser4
These outputs each fire in response to the firing of the like-numbered FireUser1 to FireUser4 Input; see User Inputs and Outputs.
OnKilled  (only in Left 4 Dead Left 4 Dead 2)
This output fires when the entity is killed and removed from the game.