# Spring Interp Quaternion Clamped

The **Spring Interp Quaternion Clamped** node applies clamped spring interpolation to a quaternion rotation. It smoothly rotates toward a target while clamping the rotation offset to specified twist/swing limits.

The key advantage over the standard Spring Interp node is that the interpolation path is also guaranteed to stay within the clamp limits. For example, if your maximum twist is 170° and you need to go from −170° to +170°, it will rotate the long way around (through 0°) rather than taking the short path (through ±180°).

The interpolation happens in <span class="fr-term" tabindex="0" data-tooltip-key="world-space"><strong>world space</strong></span> to avoid issues with the rig's global transform changing between frames.

## Usage

1. Add the **Spring Interp Quaternion Clamped** node to your Control Rig graph
2. Connect the base **Global Rotation** (e.g., the current parent rotation before applying offset)
3. Connect the **Local Offset** (e.g., the extra rotation needed to aim at a target)
4. Configure **Clamp Settings** for twist/swing limits
5. Configure **Smoothing** for the spring interpolation
6. Use the **Result** output (smoothed and clamped quaternion in <span class="fr-term" tabindex="0" data-tooltip-key="global-space">global space</span>)


## Output Pins

| Pin | Type | Description |
|-----|------|-------------|
| Result | Rotation | The smoothed result rotation in <span class="fr-term" tabindex="0" data-tooltip-key="global-space">global space</span> |

## Input Pins

| Pin | Type | Description |
|-----|------|-------------|
| Global Rotation | Rotation | The base rotation in <span class="fr-term" tabindex="0" data-tooltip-key="global-space">global space</span> (e.g., current parent rotation before applying offset) |
| Local Offset | Rotation | The rotation offset to apply in local space (e.g., extra rotation needed to aim at target) |
| Clamp Settings | [Rotation Clamp Settings](rotation-clamping.md) | Settings for clamping the local offset |
| Smoothing | [Smoothing Settings](smoothing.md) | Settings for smoothing/damping the rotation over time |

## Clamp Settings

Clamp Settings limit the local offset before and during the spring solve, so the interpolated path stays inside the allowed range instead of briefly overshooting through a forbidden pose.

See [Rotation Clamping](rotation-clamping.md) for the field breakdown.

## Smoothing

Smoothing controls how fast the result rotates toward the clamped target. Disable it when you want the result to snap directly to the clamped rotation.

See [Smoothing](smoothing.md) for the field breakdown.