Image Trace

Convert images to vector paths by tracing edges.

What it does

Image Trace converts a raster image into vector shapes. Contours are walked at a chosen brightness threshold, simplified, and fitted with smooth curves. A 3D object can be wired into Image instead: its silhouette is rendered from a camera and that is traced.

Silhouette mode produces one outline at a single threshold. Multi Threshold slices the image into brightness bands and traces each band, giving a posterised stack of shapes for stencils and screen-print separations.

When to use it

ParameterTypeDefault
imageOneOf([FieldOf(Raster), CollectionOf(Geometry)])
cameraOneOf([Camera3D])
modeString"Silhouette"
thresholdNumber0.500
levelsNumber4
invertBooleanfalse
smoothnessNumber0.500
min_areaNumber10
three_dBooleanfalse
max_trace_resolutionNumber1400
async_traceBooleanfalse
strengthNumber1

Gotchas

With nothing wired into Image, the output is an empty shape rather than an error. Check the input connection first.

Tracing runs on the GPU with a resolution ceiling: Max Trace Resolution, default 1400, hard limit around 1448. Larger sources are downsampled automatically before tracing, so very large ones lose fine detail. Lower Smoothness, or trace a cropped or scaled-down version, for more precision.

3D unprojection, the option to output world-space curves, appears only when the Image input is a 3D object. Wiring an object in switches the node to silhouette-from-camera mode.

Enable Async Trace on large images. Tracing moves to a background thread and the result fills in when ready, so the graph stays responsive. Leave it off on small images for immediate feedback while dragging Threshold or Smoothness.

Worked example

  1. Add an Image Trace node and wire an image into Image.

  2. Adjust Threshold until the silhouette matches the shape you need. Enable Invert if the trace picks up the wrong side of the edge.

  3. Raise Smoothness for flowing curves, lower it to keep sharp corners, raise Min Area to drop stray specks.

  4. Switch Mode to Multi Threshold and raise Levels for a posterised stack of shapes instead of one outline.

  5. On large sources, enable Async Trace to keep the graph responsive during retracing.

See also

Image · Levels · Raster Brush · Rasters (images)