$collisionjoints
Contents
$collisionjoints is a QC command available in all 
Source games. It is used to define a collision mesh made up of multiple independent parts, either for a ragdoll or for an animated object. If your model has no moving parts that need to collide, use $collisionmodel instead.
A ragdoll can have up to 32 separate parts (i.e. 32 bones can be simulated, 24 on older versions of Source). The limit for an animated model is 99 separate parts.
Tip:Use vcollide_wireframe 1 to view collision meshes in-game.
Warning:Each convex part will produce a phys_bone_follower entity on prop_dynamic (but not on prop_ragdoll), potentially using up large parts of the entity count and networking traffic. Using this for models that are to be repeated many times isn't a good idea!
Bug:$collisionjoints appears to have issues when only 1 joint is defined and used on a prop_dynamic. The position is broken and the joint does not animate. A workaround for this is to define a bone_followers section under $keyvalues, for example:
$keyvalues
{
bone_followers
{
"bone" "mycoolbone"
}
}
Syntax
$collisionjoints <collision mesh SMD/DMX> { <options> }
Options
- All
$collisionmodeloptions, except$concave 
Confirm:Is $masscenter allowed?- $concaveperjoint
- Permit concave collision geometry for individual bones.
- $rootbone <string|bone>
- Overrides the collision mesh's root bone.
- $jointskip <string|bone>
- Eliminates a joint in the skeleton that you don't want to use in collisions.
$jointmerge <string|bone1> <string|bone2>- Merges the vertex assignments for two joints.
$jointconstrain <string|bone> <axis> <allow_option> <min_angle> <max_angle> <friction>- Limits of the a bone's movement relative to its parent bone. See $jointconstrain for a full description.
$jointinertia <string|bone> <float|scale>- Per-bone
$inertia. $jointdamping <string|bone> <float|scale>- Per-bone
$damping. $jointrotdamping <string|bone> <float|scale>- Per-bone
$rotdamping. $jointmassbias <string|bone> <float|bias>- Mass is automatically distributed by volume, this lets you bias it per-bone.
$noselfcollisions- Disables collisions between bones in the same collision model for performance.
- Warning:Results in arms clipping through torsos and other weirdness if used improperly!
$jointcollide <string|bone1> <string|bone2>- If any
$jointcollidepairs are specified, only those joints collide with each other. - Bug:Does not work in Left 4 Dead or Left 4 Dead 2, instead disabling self collisions entirely. [todo tested in?]
$animatedfriction <float|FrictionTimeIn> <float|FrictionTimeOut> <float|FrictionTimeHold> <float|MinAnimatedFriction> <float|MaxAnimatedFriction>- Used to animate the amount of friction on joints over time. This can be used to make character death ragdolls tense up.
- Bug:Only works on C_ClientRagdoll entity, does not work on traditional player death ragdolls or serverside ragdolls. [todo tested in?]
Example
$collisionjoints "bip01_phys.smd"
{
$mass 115.0
$inertia 2.00
$damping 0.01
$rotdamping 0.40
$rootbone "bip01_pelvis"
$jointmerge "bip01_pelvis" "bip01_spine"
$jointmassbias "bip01_l_arm2" 2.00
$jointconstrain "bip01_l_arm2" x limit 0.00 0.00 0.00
$jointconstrain "bip01_l_arm2" y limit 0.00 0.00 0.00
$jointconstrain "bip01_l_arm2" z limit -120.00 4.00 0.20
$jointrotdamping "bip01_head" 5.00
$jointconstrain "bip01_head" x limit -20.00 20.00 0.00
$jointconstrain "bip01_head" y limit -25.00 25.00 0.04
$jointconstrain "bip01_head" z limit -13.00 30.00 0.04
}
