Node reference
Every node Heeler can place, what it does, what its ports carry, and how it is used. Nodes are listed by the category color they wear in the graph. The same operations appear as sections in Adjustments; the graph shows them as cards you can wire, mask, bypass and duplicate.
Two kinds of data
Wires carry one of two things, and the engine never mixes them without a node in between:
- rgb, an image. Grey square ports on the left of a card take it; the grey square on the right gives it.
- alpha, a single-channel field. Every mask, Measure, Compare, Logic, Math and Remap gives one, from the purple diamond on the right. Every node that can be limited takes one on the purple diamond at its bottom left, and the logic-family nodes take fields as their inputs.
An image becomes a field through Luminance Extract, Channel or Measure. Fields become an image through Channel Join. Hover any port to read its name and what it carries.
Categories
- Source nodes: the photograph, other pictures, and geometry.
- Color nodes: tone, white balance, grading, curves and the rendering transforms.
- Detail nodes: sharpening, smoothing, texture, grain, and the depth tools.
- Masking nodes: selections by tone, color, shape, paint and model, and the logic family.
- Utility nodes: compositing, channels, color spaces, layer content and effects.
Shared behaviour
- Bypass. Every card has a switch. Off passes the input through untouched; a source keeps giving its picture.
- Mask. A field on the mask port limits where a node applies: 1 is full effect, 0 is untouched, and a feathered field crossfades.
- Identity by default. A node fresh from the palette changes nothing until a dial moves.
- Reset. The reset glyph beside the switch, or Reset on the context menu, puts every dial and choice back to its defaults and leaves strokes and the switch alone.
- Thumbnails. Each card shows the engine's own picture at that node, so a change downstream never alters the cards before it.
See Example networks for complete graphs built from these nodes, each one rendered to prove it runs.