Technique · Fields
Liquid
Flowing paint, marbling, glossy resin and glass swells, lit like a wet surface.
Liquid is a field drawn for every pixel by the graphics chip. 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
- Ebru, Turkish marbling, floats pigment on a bath thickened with gum tragacanth and lifts the pattern off with a sheet of paper.
- A poured resin hardens by a chemical reaction rather than by drying, which is why a poured surface can come out so glassy and still.
- Stretching and folding, as when dough is kneaded, is the textbook picture of how a fluid mixes: every fold doubles the number of layers.
- Paper marbling floats ink on water or a thickened bath and lifts the pattern with a sheet of paper; the Japanese form, suminagashi, is at least eight centuries old.
- Curl noise, introduced to computer graphics by Bridson, Hourihan and Nordenstam in 2007, has no divergence by construction, which is why it looks like smoke rather than static.
The mathematics
- Curl noise is the rotated gradient of a noise potential, (dpsi/dy, -dpsi/dx), so its divergence is exactly zero: nothing piles up and nothing drains away.
- The 8 gold lines are contours: the places where one smooth field crosses 8 evenly chosen values.
- A height map is lit by the dot product of its surface normal with the light direction, which is Lambert's cosine law of 1760.
In art
- Marbled paper has been used for centuries as endpapers in bound books, and no two sheets are the same.
- Pour painters rely on the same physics as marblers: differences in density and viscosity decide how colours separate into cells and lacing.
More ways to use it
Related techniques
Nebula and stars · Droplets · Network · Terrain and maps · Neuron · Order to chaos · Fractal tree · Radiolarian shell