# Jaw Bone Lip Sync ### Overview The **Jaw Bone Target** (CrystalLipSyncJawBoneTarget**)** component is a lightweight alternative to the standard `CrystalLipSyncBlendshapeTarget`. Instead of driving SkinnedMeshRenderer blendshapes, it **rotates a jaw bone** to open and close the mouth.
This is ideal for characters that have no blendshapes at all ... the jaw simply opens wider for loud vowels and closes during silence, giving a convincing "talking" appearance at minimal cost. {% hint style="info" %} The Jaw Bone Target reads from the same `CrystalLipSyncController` as the Blendshape Target. All audio analysis, viseme classification, and smoothing features work identically ... only the output method differs. {% endhint %} *** ### When to use it | Scenario | Use Jaw Bone Target? | | ------------------------------------------------------- | --------------------------------------------------------------------------- | | **Low-poly characters** (mobile, retro, voxel) | **Yes** ... no blendshapes needed | | **Stylised / comic characters** with simple geometry | **Yes** ... one rotating bone is enough | | **Procedurally generated characters** with a rigged jaw | **Yes** ... assign the bone at runtime | | **VR hands / avatars** with a jaw bone but no face mesh | **Yes** | | **Robots / puppets** with a hinged jaw | **Yes** ... perfect mechanical open/close | | **Realistic characters** with full face blendshapes | **No** ... use `CrystalLipSyncBlendshapeTarget` instead | | **Characters with ARKit / FACS blendshapes** | **No** ... blendshape mapping gives far better results | | **Characters needing distinct vowel/consonant shapes** | **No** ... jaw-only cannot distinguish lip rounding, bilabial closure, etc. | {% hint style="warning" %} Jaw Bone lip sync produces **open/close only**. It cannot distinguish between different mouth shapes (e.g., "AH" vs "OO" vs "EE" all produce the same jaw-open). For characters where the camera is close to the face, blendshape lip sync will always look significantly better. {% endhint %} *** ### Setup #### Option A ... Setup Wizard (recommended) 1. Open **Tools → Crystal LipSync → Setup Wizard** 2. Drag your character into the **Character GameObject** field 3. If no viseme blendshapes are found, the wizard automatically suggests **Jaw Bone** mode 4. You can also manually switch the **Lip Sync Target** dropdown to `JawBone` 5. Click **Setup Character** The wizard will: * Add an `AudioSource` and `CrystalLipSyncController` (as usual) * Add a `CrystalLipSyncJawBoneTarget` instead of a `BlendshapeTarget` * Auto-detect the jaw bone in the hierarchy #### Option B ... Manual setup 1. Ensure your character has a `CrystalLipSyncController` with an AudioSource assigned 2. Add the **CrystalLipSyncJawBoneTarget** component (Add Component → CrystalLipSync → Jaw Bone Target) 3. Assign the **Controller** reference 4. Assign the **Jaw Bone** transform (or click **Auto-Detect Jaw Bone**) 5. Adjust the **Axis**, **Max Angle**, and **Invert Direction** to match your rig *** ### Settings | Setting | Default | Description | | --------------------- | -------- | ------------------------------------------------------------------------------------------------------------ | | **Controller** | ... | The `CrystalLipSyncController` that provides viseme weights and volume data. | | **Jaw Bone** | ... | The Transform to rotate. Typically the first child of the head bone (named `Jaw`, `Chin`, `Mandible`, etc.). | | **Axis** | `X` | Which local axis the jaw rotates on. Most humanoid rigs use X or Z. | | **Max Angle** | `15°` | Maximum rotation when the jaw is fully open. Typical range: 10°...25°. | | **Invert Direction** | `false` | Flip the rotation direction if the jaw opens the wrong way. | | **Drive Mode** | `Viseme` | What drives the jaw opening ... see below. | | **Smoothing Speed** | `20` | How quickly the jaw responds to changes. Higher = snappier. | | **Intensity** | `1.0` | Global multiplier for jaw opening (0...1). | | **Volume Multiplier** | `40` | Scales raw audio RMS (which is very small) up to a usable range. Only used in Volume or Combined mode. | *** ### Drive Modes | Mode | Source | Quality | Use case | | ------------ | ----------------------------- | -------- | ---------------------------------------------------------------------------- | | **Viseme** | AA (open vowel) viseme weight | Best | Default ... uses the full FFT analysis pipeline to detect open-mouth sounds | | **Volume** | Raw audio RMS amplitude | Basic | Simplest open/close; every sound opens the jaw proportionally to loudness | | **Combined** | Max of Viseme and Volume | Balanced | Uses whichever signal is stronger; catches both speech and non-speech sounds | {% hint style="info" %} **Viseme mode** is recommended for speech. It only opens the jaw for actual open-vowel sounds (AA), so the mouth stays closed for consonants like "M", "B", "S". **Volume mode** opens the jaw for any loud sound, including music, footsteps, or environmental noise playing through the same AudioSource. {% endhint %} *** ### Auto-Detection The **Auto-Detect Jaw Bone** button (and the Setup Wizard) searches the character's bone hierarchy for transforms with names containing: * `jaw`, `chin`, `mandible` * `mouth_bone`, `bn_jaw`, `bip_jaw`, `def_jaw`, `bone_jaw` It prefers bones with `lower` or `bot` in the name and avoids bones named `upper` or `lip`. If auto-detection fails, assign the jaw bone manually by dragging it from the hierarchy. *** ### Works with Text Lip Sync The Jaw Bone Target also works with `CrystalTextLipSync` for text-driven lip sync (no audio needed). When `CrystalTextLipSync` writes viseme weights into the controller, the Jaw Bone Target reads the AA weight and opens the jaw accordingly. This means the Jaw Bone Target works with: * **Audio lip sync** (real-time FFT from AudioSource) * **Text lip sync** (from CrystalTextLipSync) * **Microphone lip sync** (from CrystalMicrophoneLipSync) * **Any integration** (Game Creator 2, PixelCrushers Dialogue System, etc.) *** ### Editor Preview The custom inspector includes: * **Auto-Detect Jaw Bone** button ... finds the jaw bone in the hierarchy * **Live Debug View** (Play Mode) ... shows a progress bar of the current jaw opening * **Test Pose slider** (Edit Mode) ... preview the jaw rotation range without entering Play Mode *** ### Troubleshooting #### Jaw doesn't move 1. Check that **Controller** and **Jaw Bone** are assigned in the inspector 2. Verify the controller's **AudioSource** has audio playing 3. Try **Volume** drive mode to confirm the bone rotates at all 4. Check that **Max Angle** is high enough to be visible (try 20°) #### Jaw opens in the wrong direction * Toggle **Invert Direction** in the inspector * If still wrong, try a different **Axis** (X / Y / Z) #### Jaw snaps open/closed too fast * Reduce **Smoothing Speed** (try 10...15) #### Jaw barely opens * Increase **Max Angle** (try 20...30°) * Increase **Intensity** (try 1.0) * If using Volume mode, increase **Volume Multiplier** #### Jaw opens for non-speech sounds * Switch from **Volume** to **Viseme** drive mode ... it only responds to detected open-vowel sounds *** ### FAQ {% hint style="info" %} **Q: Can I use both Jaw Bone Target and Blendshape Target on the same character?**\ A: Technically yes, but it rarely makes sense. If your character has blendshapes, use the Blendshape Target ... it produces far better results. The Jaw Bone Target is designed for characters *without* blendshapes. {% endhint %} {% hint style="info" %} **Q: Does this work with Humanoid rigs?**\ A: Yes. The component runs in `LateUpdate` after the Animator, so it overrides the Animator's jaw rotation correctly. Just make sure the jaw bone isn't locked by an Animation Override layer. {% endhint %} {% hint style="info" %} **Q: What if my character has no jaw bone at all?**\ A: You can use any transform as the "jaw bone" ... for example, the lower half of a split-face mesh, a puppet's lower jaw piece, or any hinged object. The component just rotates whatever transform you assign. {% endhint %} {% hint style="info" %} **Q: Is there any performance difference?**\ A: The Jaw Bone Target is slightly cheaper than the Blendshape Target ... it's a single `Quaternion.Euler` + assignment vs iterating 15 blendshape weights. Both are negligible. {% endhint %}