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The QC command $sequence defines a skeletal animation. It can be used either on its own, or, to make use of Source's more advanced skeletal animation features, in conjunction with one or several $animations.

Note:All models that have any polygons must have at least one $sequence. If you don't actually want any movement, it's easiest to re-use your reference SMD. Models that solely use $includemodel do not require any $sequences.
To do: What happens if no $sequences exist in the $includemodel?


$sequence has two modes. One directly accesses a single skeletal animation (SMD or DMX), while the other needs intermediate $animations.

Note:a DMX skeletal animation may only be used if the game that the model is being compiled for has dmxconvert. a list of games which have dmxconvert can be found on this page: DMX
Note:A $sequence can only see $animations that come above it in the QC file.
$sequence <name> <skeletal animation SMD/DMX> <simple options>
$sequence <name> {		// opening brace must be on the same line as the command
	<$animation name(s)>
	<advanced options>
	<simple options>


$modelname		"weapons/shell.mdl"
$cdmaterials		"models/weapons/"
$body		shell	"shell-ref.smd"
$sequence idle	"shell-idle.smd"
$animation a_strokechin "strokechin.smd" subtract idle 0

$sequence strokechin {
$sequence run_holding_all {
	a_runS a_runSE a_runE a_runNE a_runN_SMG a_runNW a_runW a_runSW a_runS

	blendwidth 9
	blend move_yaw -180 180
	addlayer layer_run_holding
	node "running"



The name of the animation. Will appear in HLMV, Hammer, etc.
frames <start frame> <end frame>
Specifies the length of frames to use from the provided animation. The length will be moved back to 0, e.g. frames 80 110 would be recognized as a length of 0-30.

Warning: Anything relying on specific frame numbers (such as Animation Events) is not re-mapped.

To do: Write a better explanation.
origin <x> <y> <z>
Adjusts the position of the animation within its own local space.
rotate <x> <y> <z>
Adjusts the rotation of the animation within its own local space.
To do: Documentation
scale <float|scale>
Multiplies the size of the skeleton in this sequence. Negative values are accepted.
reverse (New with Counter-Strike: Global Offensive)
Reverses the animation.
<string|Skeletal animation SMD>
Path to the $sequence's source SMD. By including this, you tell studiomdl that you are using the simple version of the command.
Has three effects:
  • Causes the sequence to repeat endlessly until stopped.
  • Prevents the sequence from restarting if triggered while already playing.
  • Causes studiomdl to perform some cleanup between the first and last frames.
To do: Documentation
Prevents the $sequence from being listed in user interfaces. Useful for sequences which serve only as layers of others.
fps <float|frames per second>
Override the speed at which the animation plays. Note that these are animation frames - not screen frames! To do: Performance implications; sparse keyframes = CPU load, dense keyframes = memory load?
<string|motion extract axis>
Movement animations are easier to create if the model actually moves forwards, but for playback in-game it must "walk on the spot". This command resolves the issue by stripping root bone translation from an animation. Accepted axes are:
  • X, Y, and Z
  • LX, LY and LZ - the root bone moves along the axis until the animation is half complete, then moves back to its original position.
    Tip:You can extract motion from any combination of axes. Just put a space between each one.
This command is also available on $animations.
activity <string|name> <float|weight>
Links the sequence to an activity. The name should be one recognised by the target NPC's code. Weight modifies how likely this particular sequence is to be picked when the activity is called; if a $sequence has a weight twice that of another, it is twice as likely to be used. If an activity name starts with "ACT_" then the activity keyword can be removed. When ACT_ is seen, it is implicitly an activity.
Tip:If there is only one sequence tied to the activity, use a weight of -1.
Makes the $sequence play at all times, on top of any other animations, no matter what the model is doing. Good for blended breathing animations and other automated motion. If a model has multiple autoplay $sequences, they’re layered in the order that they appear in the QC. Warning: Don't use this for an animation that might be played normally, or you'll end up with it playing twice and the motion doubling up.
addlayer <string|other $sequence name>
Play another sequence (probably delta-ed) at the same time as this one. The animations begin and end together. The other $sequence doesn't have to be above the current one.
blendlayer <string|other $sequence name> <int|startframe> <int|peakframe> <int|tailframe> <int|endframe> [spline] [xfade]
Similar to addlayer, but the new $sequence only plays over specified frames.
  • peakframe is when the animation reaches 100% intensity, and tailframe is when it starts to fade away.
  • The spline option converts the linear start-peak and tail-end fades of the $sequence to a spline curve.
  • To do: Behaviour of xfade.
Remove all blending when transitioning to this animation. This is useful for reaction animations that are the result of sudden and violent changes in the model's state, such as a creature flinching or a weapon firing.
Ignore the $sequence's fps and time it with the global system clock instead. Useful when adding layers that shouldn't play at the same rate as their parent $sequence.
fadein <float|seconds>
Override how long this animation spends fading in. Default is 0.2.
fadeout <float|seconds>
Override how long this animation spends fading out. Default is 0.2.
weightlist <string|weightlist name>
Selects a $weightlist to apply to this sequence.
localhierarchy "<bone name>" "<parent bone name>"
Changes a bone's parent for this animation only. "" can be used to remove the parent of a bone.
Note:This does not affect animations during transitions, making snap necessary.
To do: Documentation


In addition to all simple options:

Tells Source that the $animations referenced in this sequence have all been subtracted. The $sequence will be played on top of whatever sequences are currently playing, rather than overriding them. Warning: Using this with an $animation that hasn't been subtracted has bad results!
The compliment to the "presubtract" command, this tells the animation compositing system to add the current bone setup on top of a different frame of reference instead of overriding each bones’ animation based on the typical cross-fade weighting scheme.
blend <string|name> <float|min value> <float|max value>
blendwidth <int|width>
See Blend sequence.
See $ikchain

Freezes the bone specified in an $ikchain

See $ikchain


node (name)
Tags the sequence as belonging to a point on the sequence transition graph table. This is for animations which don’t change graph state, such as looping animations. Multiple sequences can be at the same entry in the graph table, at which point they won’t need transition animations to move between each other.
Alternatively, you can have them at different points and expressly skip transitions (see $skiptransition). Sequences with no declaration are assumed at the root node and the transition graph assumes any sequence can move from the root node or to the root node without a intermediate transition.
transition (from) (to)
This specifies that the animation enters from one point on the node graph and exits at another point. This is used to play transitional sequences such as walk_to_stand, run_to_crouch, etc.
rtransition (name1) (name2)
Same as transition, but flags the sequence as able to be run in reverse order. This was used by the tentacle in HL1 but I don’t recommend it be used except in special cases.
exitphase (phase)
When transitioning between looping animations, such as "stand_to_run", this tells the movement system where to start the next sequence, assuming it’s looping. It’s also assumed that you’ve made all the sequences that share the next node to be phase matched (see startloop).
$skiptransition (name1) (name2) [(name3) ...]
This adds a rule to the transition graph to allow direct movement between all the named nodes. This is useful for transitions between unique named nodes that that may not require any specific intermediate animation. This is how to avoid the transition graph from forcing "walk" to "run" to instead be a "walk" to "stand" to "run" transition.
keyvalues { [stuff] }
Add a keyvalue block (see $keyvalues) to a specific sequence. This is used for setting up gestures for Faceposer.


Events are available when using $animations. See Animation Events.