Model Part Keyframe (Data Type)

One point on a Model Part Transformation’s timeline: the value the part should have reached at a given time.

Fields#

Field	Type	Default	Purpose
time	Float	—	When this keyframe is reached, in ticks from the start of the animation. Fractional values are allowed.
value	Float	—	The value at this instant, meaning the same thing as the transformation’s type (radians, scale offset, pivot offset, …).
easing	Easing	the transformation’s easing	The curve used to travel into this keyframe from the previous one. The first keyframe’s easing is never used.

Keyframes are sorted by time when the power loads, so the order you write them in does not matter.

How the timeline is read#

• Before the first keyframe’s time, the value is held at the first keyframe’s value.
• After the last keyframe’s time, the value is held at the last keyframe’s value — unless the transformation sets "loop": true, in which case the timeline wraps back to the start and repeats forever.
• With "easing": "step" a keyframe holds the previous value and snaps at the last moment, which is what you want for visible and hidden.
• With "easing": "catmullrom" the segment curves smoothly through the neighbouring keyframes instead of running straight between two of them. On a looping timeline the neighbours wrap around, so the loop stays smooth at the seam.

Example#

[
  { "time": 0,  "value": 0 },
  { "time": 4,  "value": -1.9, "easing": "ease_out_cubic" },
  { "time": 10, "value": -1.9 },
  { "time": 16, "value": 0,    "easing": "ease_in_out_quad" }
]

Swings to −1.9 rad over 4 ticks with a hard-out curve, holds the pose for 6 ticks, then eases back to rest over 6 more.