Fractal Flame vs Reaction–Diffusion
フラクタル・フレーム / 反応拡散パターン
Both sit in Computational Expression, so the question is not what they belong to but how they behave. They are reached for with some of the same intent, which is where they get confused.
Fractal Flame
Scott Draves's Fractal Flame adds nonlinear variations, log-density display and structural coloring to iterated function systems, producing feathered, smoky and coral-like structures from probability and transformation history.
Reaction–Diffusion
Reaction-diffusion simulation lets substances react locally while spreading at different rates, self-organizing small disturbances into spots, stripes, mazes and coral-like patterns.
| Fractal Flame | Reaction–Diffusion | |
|---|---|---|
| Era | 1992– | 1952– |
| Family | Computational Expression | Computational Expression |
| Kind | Technique | Technique |
| Cues | Translucent branching like flame or feathers / Bright high-density regions emerging from darkness / Self-similar detail continuing under magnification / Smooth color driven by transformation history | Round spots dividing at even distances / Continuous curving maze stripes / Coral or cellular boundaries branching from edges / Self-organized marks of nearly constant thickness |
| Best used for | Generating organic high-density stills and motion from mathematical iteration · Creating luminous structures for music or exhibition imagery that retain detail when enlarged | Explaining biological spot and stripe formation in research, education and exhibitions · Growing organic surface, motion and type patterns |
| Type | Keep copy outside the generated field or anchored in dark regions. | Place copy in low-density regions instead of eroding every letter with the pattern. |
| Composition | Grow branches from one dense core and preserve a dark resting field around them. | Show growth from a seed or boundary condition rather than freezing a uniform all-over print. |
| Material | Select affine transforms and nonlinear variations probabilistically, display density logarithmically and color by transform history. | Set reaction terms, diffusion rates, feed and kill rates, then iterate from a small perturbation. |
| Caution | A rainbow spiral fractal is not a Flame. Preserve nonlinear variation, density display and structural color. | A hand-drawn animal print is not reaction-diffusion. Time and parameter changes must remain visible in the pattern. |