Houdini 20.0 Nodes Geometry nodes

Trace geometry node

Traces curves from an image file or heightfield.

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This node reads an image file and automatically traces it, generating a set of faces around areas exceeding a certain brightness threshold. You can control this threshold and the resolution of the resulting faces.

If geometry is wired to this, it will instead trace one of the 2d volumes in the input, such as heightfields.


The image is fit to a 1.0 X/Y square preserving aspect ratio.

Uses / Works in Relation With

Commonly followed by an Extrude SOP to generate beveled objects from logos, scans of geographical maps, etc. It can be animated by reading in a series of images.


Layer to Trace

The name or primitive number of the layer to trace on the input.

If none is present, first primitive will be traced. It must be a two dimensional volume, such as created by heightfield tools or the Volume Slice node.



Position of center of traced image


Scale of traced image.


Rotation about the center of the image.



Minimum brightness level that should be traced.

Add Point Texture

Toggles the creation of point texture UV coordinates.


What channel of the image to use for tracing. Mono will use the brightness of the channel, and red, green, blue and alpha will use those channels if present.

File Switch

Image Input

Name of the file to use.

Scale to Size

Loads the file at the specified resolution rather than its actual resolution.

COP Switch

COP Path

The path to the COP to use.

COP Frame

Which frame(s) to use from a cop composed of a sequence of images.


Which planes to use as the source.


Remove Borders

Attempts to remove borders from the trace.

Border Width

The width of border to remove.

Resample Shapes

Enables the manual Step Size option

Step Size

The distance between adjacent points.

Smooth Shapes

Attempts to round corners.

Corner Delta

Value controlling corner smoothing.

Fit to Curves

Attempts to map Bezier curves to trace.

Fitting Error

Controls the accuracy of curve fitting.

Convert to Poly

Converts Fit to Curves to Polygons.

Level of Detail

Density of Polygon points.

Hole Faces

Bridges all holes in the output for proper rendering.

Boundary Color

Set this to Black for tracing white shapes on a black background, White for tracing black shapes on a white background, or Same as (0,0) to use the color of pixel (0,0) in the image to automatically guess the background color. For image sequences, you’ll usually want this set to Black or White, in case the shape overlaps pixel (0,0).

Boundary Value

The boundary value to use in Custom mode.

Missing Frame

What should be done if the specified file does not exist on disk. By default, if no file of the given name exists, the SOP will error. This can be troublesome if the input rotosequence has holes.

Geometry nodes