phys_constraintsystem

phys_constraintsystem is a point entity available in all Source games. If you have a collection of objects connected by constraints, you may encounter vibration or jiggling. This is because each constraint is solved without regard for any others until you introduce a phys_constraintsystem.

To implement a phys_constraintsystem create one and give it a name, then select the constraints you want to group together and set it as their "Constraint System Manager".

A constraintsystem also allows you to control the number of iterations performed on the constraints, allowing you to allocate more CPU to get the solution tighter. This will help when objects of dissimilar mass are connected, as if a large-mass object is in violation of the constraint it will take more iterations for it to move to a non-violating position/orientation. Ragdolls create a constraint system internally to solve these issues.

Keyvalues

Additional System Iterations <integer>

Adding iterations makes the interactions among constraints in a system tighter. It will not compensate for errors due to collision, but will help in cases where objects of disparate mass are constrained to each other.

Targetname:

Name (targetname) <string>

The targetname that other entities refer to this entity by.

Entity Scripts (vscripts) <scriptlist> (in all games since )

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 )

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.

Inputs

Targetname:

Kill

Removes this entity from the world.

KillHierarchy

Removes this entity and its children from the world.

 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 )

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 )

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.

CallScriptFunction <string> (in all games since ) !FGD

Execute a VScript function in the scope of the receiving entity.

SetLocalOrigin <coordinates> (in all games since ) !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 ) !FGD

Set this entity's angles.

Outputs

Targetname:

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 )

This output fires when the entity is killed and removed from the game.