Technique · Geometry
Flow ribbons
Parallel strands that curl through a smoke-like flow: bundles of lines or dotted lines spiralling into vortices.
Flow ribbons is drawn geometry, rebuilt as it changes. Every piece on Synapse Drip is made from a recipe that layers techniques like this one, and you can change any of it in the Studio.
Good to know
- Combed marbling drags a comb through floating ink to make parallel strands, which a marbler then bends with a stylus.
- The jet stream, a river of air high above the Earth, meanders in great waves, and a flow that varies smoothly carries neighbouring paths along together, as it carries these strands.
- Curl noise, introduced to computer graphics in 2007, is built so that nothing piles up or drains away, which is why strands loop instead of bunching.
- The streamlines of a steady flow can never cross, which gives pictures like this their calm.
The mathematics
- In curl noise the velocity is perpendicular to the gradient of a noise potential, so every strand runs along a contour of that potential and never leaves it.
- 14 bundles start close together; in a smooth flow nearby paths drift apart only slowly, so each bundle stays parallel for a long way before a vortex pulls it apart.
In art
- Bridget Riley's Current (1964) uses undulating black and white stripes that seem to vibrate: a classic of Op art.
- Hokusai's Great Wave, from about 1831, draws water as curling bands of line, a long tradition that these strands continue.
More ways to use it
Related techniques
L-system · Space colonisation · Diffusion-limited aggregation · Ridgelines · Curve families · Streamlines · Paint strokes · Stipple and Delaunay portrait