Motion Path
Generate an editable bezier path from an object's animated trajectory.
What it does
Motion Path samples an animated shape or null across a range of frames, fits a smooth bezier curve through its trajectory, and outputs an editable path. Drag its anchor points and handles like any bezier curve. The difference between the edit and the original sampled path comes back out as per-frame position deltas, ready to wire into an Add node to push the offset onto the object that generated it.
Frame Start and Frame End set the sampling window; leave both at 0 to auto-detect a range from the timeline. Fit Tolerance controls how tightly the curve hugs the raw trajectory, lower meaning more anchor points and a closer fit.
When to use it
Seeing and editing an object's motion as a curve rather than a keyframe list.
Nudging, smoothing, or restyling an existing animation without touching the original keyframes.
A trail or ribbon tracing where something has been.
Locking a hand-tuned path so it stops re-sampling when the upstream animation changes.
| Parameter | Type | Default |
|---|---|---|
source | Any | — |
frame_start | Number | 0 |
frame_end | Number | 0 |
fit_tolerance | Number | 1 |
edited_points_json | String | "" |
original_points_json | String | "" |
baked | Boolean | false |
extrapolate | Boolean | false |
resample | Boolean | false |
radius | Number | 1 |
color | Color | rgba(0.40, 0.80, 1.00, 1.00) |
strength | Number | 1 |
Gotchas
Bake locks the path against the source. While unbaked, the curve re-fits from the upstream animation on every change, so handle tweaks only stick once Bake is on.
Extrapolate controls what happens outside the sampled frame range. Off, the default, clamps the delta offsets to zero past the ends of the range. On lets the edited path keep influencing frames beyond it.
Resample re-fits the edited curve at the current Fit Tolerance and can reduce the point count. Use it to simplify an over-detailed curve after editing, rather than lowering tolerance and re-sampling from scratch.
Worked example
Wire an animated shape or null into Source.
Set Frame Start and Frame End to the range you want to trace (or leave both at 0 to auto-detect).
Lower Fit Tolerance if the curve is cutting corners on a fast motion.
Edit the anchor points and handles directly on the curve to reshape the path.
Turn on Bake to lock the edit in, then wire Delta Offsets into an Add node feeding the original object's position to apply your edit back onto it.