# Edges Module

Edges is about line quality — which boundaries in a photo are crisp, which dissolve into their neighbour, and where a form genuinely changes direction. It's the module closest to a traditional line drawing or ink study.

## Basic Edges

A straightforward line drawing extracted from the photo, a good starting point for any linework study.

![Basic Edges applied to the reference photo at basic settings](examples/edges-basic-edges.jpg)

*Basic Edges at its default detail level — a clean line drawing of the car and treeline, ready to trace or draw from directly.*

- **Detail Amount** — how much detail to capture; lower shows more lines, higher shows only the strongest edges.
- **Smoothing** — softens the photo before finding lines, reducing noise and small distracting details.
- **Line Thickness** — how thick the drawn lines appear.

## Directional

Highlights edges that run in a particular direction, useful for studying the "flow" or gesture running through a composition.

- **Edge Sensitivity** — which edges get a stroke; lower catches more subtle forms.
- **Line Width** — how thick each stroke appears.
- **Stroke Length** — how long each individual gesture stroke is drawn.
- **Stroke Spacing** — the gap between strokes; tighter spacing shows more detail.

## Hierarchical Edges

Separates strong, structural edges from minor, textural ones, so you can draw the important lines first and add detail later, the way a life-drawing teacher would tell you to.

- **Show Major Forms / Secondary Edges / Fine Details** — three switches to show or hide each tier of line on its own.
- **Line Thickness** — how thick the drawn lines appear.
- **Major Form / Secondary Edge / Detail Sensitivity** — three separate sliders that adjust what counts as "major," "secondary," or "fine detail" for each tier.

## Simplified Forms

Reduces the linework to the minimum needed to still read as the subject — good for gesture practice.

- **Simplification Amount** — higher values show only the largest forms.
- **Minimum Shape Size** — ignores shapes smaller than this percentage of the image.
- **Line Thickness** — how thick the drawn lines appear.

## Value Contours

Draws lines only where value actually changes, tying this module back to the Value module's breakdown.

- **Value Levels** — how many light-to-dark bands to derive contour lines from; fewer levels means simpler, bolder contours.
- **Smoothing** — softens the photo to reduce noise and find cleaner contours.
- **Line Thickness** — how thick the drawn lines appear.

## Shadow Boundaries

Traces just the edges of shadow shapes, useful when you only care about where light meets dark, not every surface detail.

- **Shadow Darkness Level** — how dark a value has to be to count as shadow; adjust this to match the lighting in your reference.
- **Smoothing** — softens the photo to get cleaner shadow boundaries.
- **Show Form Edges** — also shows lighter form edges for context alongside the shadow boundaries.
- **Line Thickness** — how thick the drawn lines appear.

## Lost & Found

Flags edges that fade out or "lose" themselves into a neighbouring shape versus ones that stay crisp — a classic painterly device worth noticing before you commit to a hard outline everywhere.

- **Sharp Edge Level** — edges stronger than this appear crisp and "found," drawing the eye.
- **Soft Edge Level** — edges weaker than this are "lost" and blend away, creating atmosphere.
- **Transition Softness** — how gradually edges shift from found to lost.
- **Line Thickness** — how thick the drawn lines appear.

## Color Underpainting

Combines a line study with a soft colour underlayer, closer to how a traditional underpainting looks before rendering begins.

- **Color Areas** — fewer gives bigger, bolder colour shapes; more gives finer colour detail.
- **Soften Colors** — blends neighbouring colours together for smoother, simpler areas.
- **Color Boundaries** — darkens the border between colour areas, from soft blending to clear separation.
- **Color Intensity** — pushes colours richer or pulls them back toward muted tones.
- **Tracing Paper** — like laying tracing paper over the painting; slide it up to lighten the colour so your lines stand out more clearly.
- **Show Big Shapes** — lays the major shape outlines over the colour, with its own colour and thickness controls.
- **Show Light/Dark Contours** — adds lines where light areas meet dark areas, with its own colour and thickness controls.
- **Show All Lines** — adds every visible edge as a full line drawing, with its own colour and thickness controls.
- **Line Darkness** — how dark the combined lines appear over the colour underneath; lower gives a ghosted look, higher gives strong lines.

## How to use it

If you're not sure where to start, try **Basic Edges** first, then **Hierarchical Edges** to see which of those lines actually matter. **Lost & Found** is worth a look on any photo with strong lighting — it'll usually reveal that far fewer edges are truly "hard" than you'd assume.