> ## Documentation Index
> Fetch the complete documentation index at: https://docs.comfy.org/llms.txt
> Use this file to discover all available pages before exploring further.

# SAM3DBody_FaceExpression - ComfyUI Built-in Node Documentation

> This node adds facial expressions to a SAM3D body by detecting faces in an image with the MediaPipe Face Landmarker, matching each detected face to a tracked person, and mapping th

This node adds facial expressions to a SAM3D body by detecting faces in an image with the MediaPipe Face Landmarker, matching each detected face to a tracked person, and mapping the 52 ARKit blendshapes onto MHR's 72-axis expression parameters. It then re-runs the body model so the output mesh vertices and keypoints match the new expression.

## Inputs

| Parameter                  | Description                                                                                                                                                                                                        | Data Type          | Required | Range                                |
| -------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------ | -------- | ------------------------------------ |
| `sam3d_body_model`         | The SAM3D body model containing the face landmark detector used to detect faces and regenerate the body mesh.                                                                                                      | SAM3D\_BODY\_MODEL | Yes      | -                                    |
| `mhr_pose_data`            | Pose data containing per-frame tracked persons with bounding boxes, keypoints, and expression parameters. The node matches each detected face to a person and writes updated expression parameters into this data. | MHR\_POSE\_DATA    | Yes      | -                                    |
| `image`                    | Image frames used to detect faces. If the image batch has fewer frames than the pose data, the last frame is reused for the remaining frames.                                                                      | IMAGE              | Yes      | -                                    |
| `strength`                 | Global multiplier on all blendshapes. >1 exaggerates. Default: 1.0.                                                                                                                                                | FLOAT              | No       | 0.0 to 4.0 (step 0.05, default 1.0)  |
| `mouth_strength`           | Multiplier on mouth/jaw shapes. MediaPipe's jawOpen saturates near 1.0. Default: 1.0.                                                                                                                              | FLOAT              | No       | 0.0 to 4.0 (step 0.05, default 1.0)  |
| `eye_strength`             | Multiplier on eye shapes. MediaPipe rarely exceeds 0.5; 2-3x often needed. Default: 2.0.                                                                                                                           | FLOAT              | No       | 0.0 to 4.0 (step 0.05, default 2.0)  |
| `brow_strength`            | Multiplier on brow/cheek/sneer shapes. MediaPipe outputs \~0.1-0.3; 2-3x. Default: 2.0.                                                                                                                            | FLOAT              | No       | 0.0 to 4.0 (step 0.05, default 2.0)  |
| `input_threshold`          | Deadzone on MediaPipe's raw output (below = zero, above = linear remap). Default: 0.02.                                                                                                                            | FLOAT              | No       | 0.0 to 0.5 (step 0.01, default 0.02) |
| `blendshape_smooth_window` | Gaussian window on MediaPipe's per-frame signal before MHR mapping. MediaPipe's raw output swings 30-70% frame-to-frame on static faces. 1 = disabled. Use odd values. Default: 7.                                 | INT                | No       | 1 to 31 (step 2, default 7)          |

Note: A per-clip baseline subtraction is applied only when at least 30 frames in the clip contain detected persons. Detection gaps of up to 12 frames per person are filled by interpolation.

## Outputs

| Output Name     | Description                                                                                                                                                                    | Data Type       |
| --------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------- |
| `mhr_pose_data` | The updated pose data. Each tracked person's expression parameters are replaced with the mapped face expression, and the mesh vertices and keypoints are regenerated to match. | MHR\_POSE\_DATA |

> This documentation was AI-generated. If you find any errors or have suggestions for improvement, please feel free to contribute! [Edit on GitHub](https://github.com/Comfy-Org/embedded-docs/blob/main/comfyui_embedded_docs/docs/SAM3DBody_FaceExpression/en.md)

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