Open a Live2D avatar’s Idle section to configure idle motions, tracking-loss behavior, and automatic breathing.
Idle Animation
Idle Animation, located in the Idle section, is enabled by default: it loops an underlying motion whenever no other motion is playing.
The Motion setting beneath it specifies which motion to loop. The default Idle Group randomly plays motions from the model's native Idle group (the standard Cubism engine behavior). Alternatively, you can select a specific motion to loop continuously.
The idle animation plays at the lowest priority: any one-shot motion overrides it, and face tracking writes over its parameters. When higher-priority motions finish, control blends smoothly back into the idle animation over its configured fade-out time.
If a selected idle motion is no longer present after switching or reloading models, the system automatically falls back to random playback from the Idle group.
When Tracking Is Lost
Also located in the Idle section, this setting controls how tracked parameters behave when face tracking is interrupted:
| Option | Behaviour |
|---|---|
| Keep Last Pose | Freeze on the last frame received until tracking resumes (default) |
| Return to Idle | Smoothly blend to the idle animation values over ~0.3 s, and blend back when tracking resumes |
Live2D models offer two additional advanced settings: Tracking-Lost Motion specifies a model motion that replaces the idle animation once tracking has been lost for a set duration, returning when tracking resumes; Delay determines the wait time before triggering this motion (0 to 60 seconds, default 3 seconds). Both options remain hidden until a tracking-lost motion is selected.
VRM avatars also include the When Tracking Is Lost setting, but without custom lost-motion options—see VRM Idle Behaviour.
Auto Breath
Auto Breath, found in the Idle section, is the Cubism engine's built-in procedural breathing motion. It can be toggled per model instance and is enabled by default. Depth scales the motion amplitude: 1 corresponds to the standard Cubism sample depth, up to a maximum of 2.
The breathing algorithm drives more than just ParamBreath: it also gently sways ParamAngle* and ParamBodyAngleX, layering subtle head and body motion on top of tracking. Because VTube Studio only animates the specific parameter configured in .vtube.json, models tuned for VTube Studio may exhibit more movement in Persona. Lower the depth or disable the toggle if desired.
Turning off Auto Breath stops the breathing motion while preserving the configured depth setting for when it is re-enabled.
Last updated on October 11, 2026