Body Tracking
Track a person's body pose, dense face mesh with blendshapes, hands, and gestures.
What it does
Body Tracking runs a single machine-learning model over an image to find a person: body pose, hands and face at once. The full set of pins is always present, body keypoints, left and right hand keypoints, face keypoints, a skeleton preview and per-point confidences, so downstream wiring survives a toggle being flipped. Regions that are switched off come through empty.
Dense Face gives a 478-point face mesh plus 52 expression blendshape coefficients, Dense Hands gives finer hand landmarks, and Gestures gives a per-hand gesture label. A One-Euro smoothing filter is on by default to settle per-frame jitter, and the skeleton preview draws over the image while the node is selected.
When to use it
A scene driven from a person on camera: puppeting a character, triggering effects from a pose, placing objects at a hand
Facial animation or expression data, from Dense Face and Blendshapes, as ARKit-style coefficients for a face rig
Hand gestures (open palm, fist, thumbs up, peace sign and similar) as a trigger, without a hand-built classifier
The face alone: Detector Source set to face-only, a lighter and more accurate face-only detector
| Parameter | Type | Default | What it does |
|---|---|---|---|
image | Raster | — | Image to track a person in (connect Camera Input) |
enabled | Boolean | true | Enable tracking |
detector_source | String | "whole_person" | Detector source — whole-person RTMW pose, or a face-only detector (BlazeFace ROI). One of: whole_person, face_only. |
model_quality | String | "balanced" | Model tier — falls back to the balanced model if the selected tier isn't installed. One of: fast, balanced, accurate. |
confidence_threshold | Number | 0.300 | Body confidence threshold (also the fallback for feet) |
hand_confidence | Number | 0.200 | Hand confidence threshold — usually lower than body (hands are smaller / more occluded) |
face_confidence | Number | 0.200 | Face confidence threshold — usually lower than body |
min_detection_confidence | Number | 0.500 | Minimum detection confidence (face-only source) |
min_tracking_confidence | Number | 0.500 | Minimum tracking confidence (face-only source) |
dense_face | Boolean | false | Upgrade the face region to a dense 478-point FaceMesh |
blendshapes | Boolean | true | Output the 52 ARKit expression blendshape coefficients (only fires when Dense Face is on) |
dense_hands | Boolean | false | Upgrade the hand regions to dense hand-landmarker keypoints |
gestures | Boolean | false | Classify a canned gesture label per hand |
smoothing | Boolean | true | Temporally smooth landmarks (One-Euro filter) to remove per-frame jitter |
smoothing_min_cutoff | Number | 1 | Smoothing min cutoff — lower is smoother but adds lag at rest |
smoothing_beta | Number | 0.500 | Smoothing speed coefficient (beta) — higher reduces lag during fast motion |
line_width | Number | 3 | Line thickness for skeleton bones |
joint_radius | Number | 6 | Radius of joint circles |
point_size | Number | 2 | Radius of dense-mesh preview points |
color | Color | rgba(0.00, 1.00, 0.00, 1.00) | Color for skeleton lines and joints |
preview_regions | String | "all" | Which skeleton regions to show in preview. One of: body, hands, face, all. |
opacity | Number | 1 | Layer opacity (0 = transparent, 1 = opaque). Editable, wirable, keyframable. |
Gotchas
Blendshapes only fire when Dense Face is also on. Blendshapes alone, with Dense Face off, outputs nothing.
Hand and face confidence thresholds default lower than the body threshold, because hands and faces are smaller and are occluded more easily. When gestures or face data drop out, lower Hand/Face Confidence rather than the main Confidence Threshold.
Lower Smoothing Min Cutoff for calmer tracking at rest, at the cost of more lag on quick movement. Raise Smoothing Beta to claw that lag back during fast motion.
If a Model Quality tier is not installed, the balanced model is used instead with no other sign of it. Check results when expecting the accurate tier.
Worked example
Add Body Tracking and wire a Camera or Image into its input.
Leave Detector Source on whole-person and Enabled on. A skeleton preview draws over the image.
Turn on Dense Face and Blendshapes to get facial expression coefficients for a face rig.
Turn on Dense Hands and Gestures to get finer hand tracking plus a canned gesture label per hand.
If tracking looks jittery at rest or laggy in motion, adjust Smoothing Min Cutoff and Smoothing Beta to taste.