Model Part Transformation (Data Type)

A single edit to one named part of a biped model, used by the Modify Model Parts power type.

By default the edit snaps on and off with the power. Add duration to make it ease in and out instead, or keyframes to make it animate — see Animating a part.

Fields#

Field	Type	Default	Description
model_part	String	—	The part to edit. One of head, hat, body, right_arm, left_arm, right_leg, left_leg. Matching ignores case and separators (right_arm = rightArm = rightarm). On players the matching skin-overlay layer is edited together with the base part.
type	String	—	Which property to change. See the table below.
value	Float	—	The amount. Its meaning depends on type (see below). Required unless keyframes is set, in which case it is ignored.
override_animation	Boolean	false	For pitch/yaw/roll only: if true, the value becomes the absolute rotation and the vanilla animation for that axis is ignored (“locked”). If false, it is added on top of the animation.
keyframes	Array of Model Part Keyframe	[]	A timeline of values. When set, this replaces value and the part animates instead of holding still. The clock starts at 0 the moment the power becomes active.
loop	Boolean	false	If true, the keyframe timeline repeats forever. If false, it plays once and holds the last keyframe’s value.
duration	Float	0	Ticks to fade the whole transformation in when the power becomes active. 0 applies it instantly, which is the original behaviour.
fade_out_duration	Float	duration	Ticks to fade the transformation back out when the power stops applying. Set it separately for an asymmetric fade (snap in, ease out).
easing	Easing	linear	The curve used for the fade in and out, and the default curve for any keyframe that does not name its own.

type values#

type	Effect of the value
pitch	Rotation around the X axis, in radians. Additive, or absolute when override_animation is true.
yaw	Rotation around the Y axis, in radians. Additive, or absolute when override_animation is true.
roll	Rotation around the Z axis, in radians. Additive, or absolute when override_animation is true.
x_scale	Added to the part’s base X scale (base is 1.0, so 0.5 → 1.5, -1.0 → 0.0).
y_scale	Added to the part’s base Y scale.
z_scale	Added to the part’s base Z scale.
pivot_x	Added to the part’s X pivot (position) offset.
pivot_y	Added to the part’s Y pivot offset.
pivot_z	Added to the part’s Z pivot offset.
visible	Sets visibility: 0 hides the part (and its children), any other value shows it. override_animation is ignored.
hidden	Sets the “skip draw” flag: non-0 skips drawing this part’s own cubes while still drawing its children. override_animation is ignored.

Animating a part#

Two independent controls, and they combine:

• duration / fade_out_duration / easing blend the transformation in and out. Think of it as a strength dial from 0 to 1: at 0 the part is untouched, at 1 the edit is fully applied. Rotations with override_animation blend from the vanilla animation towards your value; everything else scales down proportionally.
• keyframes / loop decide what the value is at each moment. The clock starts at 0 when the power becomes active and is measured in ticks.

visible and hidden cannot be half-applied. They flip once the fade passes the halfway mark, in both directions.

Interrupting a fade does not pop: if the power comes back before the fade-out finishes, the fade-in resumes from wherever it got to. Re-activating a power does restart its keyframe timeline from 0.

Examples#

A pose that eases on instead of snapping:

{
  "model_part": "right_arm",
  "type": "pitch",
  "value": -1.5708,
  "override_animation": true,
  "duration": 8,
  "fade_out_duration": 4,
  "easing": "ease_out_back"
}

Over 8 ticks the arm rotates from wherever the walk animation has it to straight forward (−90°), overshooting a little at the end. When the power stops applying it returns over 4 ticks.

A looping animation in a single transformation:

{
  "model_part": "head",
  "type": "roll",
  "loop": true,
  "easing": "catmullrom",
  "keyframes": [
    { "time": 0,  "value": 0 },
    { "time": 15, "value": 0.2 },
    { "time": 30, "value": 0 },
    { "time": 45, "value": -0.2 },
    { "time": 60, "value": 0 }
  ]
}

The head sways side to side on a 3-second cycle, on top of whatever the vanilla animation is doing.

A blink, using step so the value never lands between visible and invisible:

{
  "model_part": "hat",
  "type": "visible",
  "loop": true,
  "keyframes": [
    { "time": 0,  "value": 1 },
    { "time": 55, "value": 0, "easing": "step" },
    { "time": 58, "value": 1, "easing": "step" }
  ]
}