$jointconstrain: Difference between revisions

Latest revision as of 21:23, 18 July 2025

$jointconstrain is a QC command available in all Source games. It is a parameter of $collisionjoints. It is used to set the limit of a named bone's movement relative to its parentbone in a jointed collision model.

Syntax

$jointconstrain <bone_name> <axis> <allow_option> <min_angle> <max_angle> <friction>

where

<bone_name>

is the name of the 'child' bone as opposed to the 'parent' bone of the joint.

<axis>

specifies either the X, Y, or Z axis of rotation.

<allow_option>

can be one of three values:

Free : ensures the joint can move between a <min_angle> of -360 and a <max_angle> of 360, with a selectable <friction>. Ignores user specified <min_angle> and <max_angle> values.
Fixed : ensures the joint does not move at all. <min_angle>, <max_angle> and <friction> values are effectively locked to "0".
Limit : ensures the joint is completely customizable. The user must specify <min_angle>, <max_angle> and <friction> values.

<min_angle>: specifies the minimum angle of rotation about <axis> in degrees. (No lower than -360).
<max_angle>: specifies the maximum angle of rotation about <axis> in degrees. (No higher than 360).
<friction>: specifies the Friction value
Todo: scale? integer?
.

Example

For example, the right-hip joint of a valvebiped is defined by constraining the movement of valvebiped.bip01_r_thigh in relation to its parent bone (which would be valvebiped.bip01_pelvis). Notice we need a separate $jointconstraint for each axis of rotation.

$collisionjoints "phymodel.smd" {
	$mass 70.0
	$inertia 10.00
	$damping 0.01
	$rotdamping 1.50
	$rootbone "valvebiped.bip01_pelvis"
	$jointmerge "ValveBiped.Bip01_Pelvis" "ValveBiped.Bip01_Spine1"

 	$jointconstrain "valvebiped.bip01_r_thigh" x limit -12.00 12.00 0.00  // from -12 to 12 degrees in the X-axis - twist knee left/right
 	$jointconstrain "valvebiped.bip01_r_thigh" y limit  -8.00 75.00 0.00  // from -08 to 75 degrees in the Y-axis - spread knees
 	$jointconstrain "valvebiped.bip01_r_thigh" z limit -97.00 32.00 0.00  // from -97 to 32 degrees in the Z-axis - raise knee
	
	//etc
	}

Warning:These axes of rotation are always local, respective to the orientation of each bone. This means that, for instance, what the X axis is for one model's joint may be different for another.

@@ Line 1: / Line 1: @@
-The [[QC Command]] [[$jointconstrain]] is used to set the limit of a joint's movement when compiling the [[$collisionmodel]].
+{{This is a|name=$jointconstrain|QC command}} It is a parameter of [[$collisionjoints]]. It is used to set the limit of a named [[bone]]'s movement relative to its parentbone in a [[jointed collision model]].
 == Syntax ==
   $jointconstrain <bone_name> <axis> <allow_option> <min_angle> <max_angle> <friction>
 where
-; <bone_name> : {{todo|is the name of the 'child' bone as opposed to the 'parent' bone of the joint? - see example}}.
+; <bone_name> : is the name of the 'child' bone as opposed to the 'parent' bone of the joint.
 ; <axis> : specifies either the X, Y, or Z axis of rotation.
 ; <allow_option> : can be one of three values:
@@ Line 12: / Line 12: @@
 ; <min_angle> : specifies the minimum angle of rotation about <axis> in degrees. (No lower than -360).
 ; <max_angle> : specifies  the maximum angle of rotation about <axis> in degrees. (No higher than 360).
-; <friction> : specifies the Friction value {{todo|scale? integer?}}.
+; <friction> : specifies the Friction value {{TODO|scale? integer?}}.
 === Example ===
-For example, to constrain the movement of ''joint_spine'' within a range of 20 to 100 degrees on the X-axis, with a friction of 0.20:
+For example, the right-hip joint of a valvebiped is defined by constraining the movement of ''valvebiped.bip01_r_thigh'' in relation to its parent bone (which would be ''valvebiped.bip01_pelvis''). Notice we need a separate $jointconstraint for each axis of rotation.
- $jointconstrain "joint_spine" x limit 20.00 100.00 0.20.
+ [[$collisionjoints]] "phymodel.smd" {
+ 	$mass 70.0
+ 	$inertia 10.00
+ 	$damping 0.01
+ 	$rotdamping 1.50
+ 	$rootbone "valvebiped.bip01_pelvis"
+ 	$jointmerge "ValveBiped.Bip01_Pelvis" "ValveBiped.Bip01_Spine1"
+  	'''$jointconstrain "valvebiped.bip01_r_thigh" x limit -12.00 12.00 0.00'''  // from -12 to 12 degrees in the X-axis - twist knee left/right
+  	'''$jointconstrain "valvebiped.bip01_r_thigh" y limit  -8.00 75.00 0.00'''  // from -08 to 75 degrees in the Y-axis - spread knees
+  	'''$jointconstrain "valvebiped.bip01_r_thigh" z limit -97.00 32.00 0.00'''  // from -97 to 32 degrees in the Z-axis - raise knee
+ 	//etc
+ 	}
+: {{warning|These axes of rotation are always local, respective to the orientation of each bone. This means that, for instance, what the X axis is for one model's joint may be different for another.}}
-[[Category:QC Commands]]

$jointconstrain: Difference between revisions

Latest revision as of 21:23, 18 July 2025

Syntax

Example

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