Home > The halftone pipeline

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Driving geometry from an image - Image -> Image Sample -> Graph Mapper -> a field-aware node -> Realize.

Locus can drive geometry from an image, so a photo or gradient becomes a field of varying dots, lines, or tiles - a halftone. It's a small, composable pipeline of nodes.

1. Image - load a raster image into the node graph.
2. Image Sample - read the image's brightness (or a specific channel) into a value field: a function that returns a number for any point in space, based on the pixel there. It handles how the image wraps or stretches across your design.
3. Graph Mapper - remap those values through an editable curve (like Photoshop's Curves), with output min/max - so you control how brightness maps to your effect. It has a preview toggle for the on-canvas field ghost.
4. A field-aware node - feed the field into a node that accepts one (Scale, Offset, Circle radius, Rotate angle, Place, ...). The node samples the field per item, giving each shape a value based on where it sits.
5. Realize - make the resulting field of geometry real.

A grid of small shapes -> Scale driven by an image field -> each shape sized by the local brightness = a classic halftone. Swap Scale for Rotate or Offset and the same image drives a different effect. Here it is end to end.

1 - Place the image and draw the motif. Reference two points as the image's lower corners (LL, LR), then draw one small square at the origin - the shape to repeat.

2 - Array the square across the image. An Array node fills the image's footprint with copies - here a 21x21 grid at 11 mm spacing.

3 - The node graph. The referenced Square Region feeds Array; the image's brightness (Image -> Image Sample) feeds Scale's Scale input; Array feeds Scale's Geometry. Scale samples the field per copy. (This minimal example previews each stage and skips the optional Graph Mapper.)

4 - The result. Each copy is scaled by the brightness under it - large where the image is bright, shrinking to nothing where it's dark. A halftone.

See Field-aware nodes for which inputs read a field.

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