> For the complete documentation index, see [llms.txt](https://docs.convai.com/api-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.convai.com/api-docs/plugins-and-integrations/convai-unity-sdk/embodiment/body-language.md). # Body language Find guides for adding ambient posture, breathing, weight shifts, and small reactive movements that keep a Convai character's body alive between animations. Body Language is the Convai embodiment module that gives a character continuous, ambient nonverbal behavior: breathing, weight shifts, small gestures, and reactive flinches that never stop between authored actions. Body Animation plays authored clips — a walk cycle, a wave — and Body Language never owns a clip; it only adds small procedural motion on top of whatever the character is already doing. One component, `ConvaiBodyLanguageController`, drives all of it. *** ### What body language gives a character | Behavior | What it looks like | | ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Breathing | The chest and shoulders expand and contract on a continuous cycle, with occasional sharper intakes on interruption, a settling sigh, and a deeper breath before the character starts speaking. | | Weight shifts and sway | The character periodically transfers its weight between feet and drifts gently on the spot, the way a standing body constantly micro-balances rather than holding perfectly still. | | Gesticulation | While speaking, small head beats and posture pulses ride the character's speech rhythm, and its hands stay subtly alive between authored gestures instead of sitting rigid. | | Listening posture | While listening, the character leans in slightly and settles into stillness, with an occasional attentive head tilt. | | Fidgets | While idle or thinking, a slow lateral weight shift keeps the character from looking frozen. | | Reactions | A sudden emotion spike — surprise, amusement — can trigger a one-shot startle flinch or an amused bounce. | Add `ConvaiBodyLanguageController` to a character through **Convai > Embodiment > Body Language** and it works immediately on the SDK's built-in tuning — no profile asset is required to see breathing and weight shifts in Play mode. *** ### How it differs from body animation Body Animation and Body Language both move the character's skeleton, but they solve different problems and never fight over the same motion: | | Body Animation | Body Language | | ------------------- | -------------------------------------------------------------------- | ----------------------------------------------------------------------------- | | What it plays | Authored clips: idles, walk cycles, talk overlays, actions, pointing | No clips at all — continuous procedural motion computed every tick | | What it owns | The character's locomotion and any deliberate, recognizable motion | Ambient life layered on top: breathing, weight shift, posture, small gestures | | How the two combine | Plays its clip through the `PlayableGraph` as usual | Adds small, swing-only deltas on top of whatever Body Animation already posed | A character can carry either module alone, or both together. When both are present, Body Language reduces itself rather than overriding Body Animation — see [How body language works](/api-docs/plugins-and-integrations/convai-unity-sdk/embodiment/body-language/how-body-language-works.md) for the suppression rule that makes this coexistence reliable. *** ### Where to start {% content-ref url="/pages/MJQ5YSw828fv9gI3iju4" %} [Body language quick start](/api-docs/plugins-and-integrations/convai-unity-sdk/embodiment/body-language/quick-start.md) {% endcontent-ref %} *** ### Explore body language
How body language works
The behavior directors that produce this motion, and how it yields to scripted gestures.		How body language works
Body language quick start
Add the component to a character and see breathing, weight shift, and idle life running.		Body language quick start
Tune expressiveness
Make a character subtle or theatrical with the ExpressivenessPreset dial and per-behavior gains.		Tune expressiveness
Trigger gestures and reactions
Request a scripted head gesture, a semantic gesture cue, or a one-shot reaction from code.		Trigger gestures and reactions
Body language profile reference
Every ConvaiBodyLanguageProfile field, grouped by section, with defaults.		Body language profile reference
Body language scripting reference
The ConvaiBodyLanguageController public API: readings, handles, and enums.		Body language scripting reference
Troubleshoot body language
No motion, motion fighting a scripted animation, and refused gesture requests.		Troubleshoot body language
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