Complex dynamics & chaos

The Burning Ship fractal

The Burning Ship modifies the quadratic iteration by taking absolute values of the real and imaginary components before squaring. A tiny algebraic change produces a dramatically different parameter plane.

Burning Ship fractal with red islands on a turquoise field
Burning Ship in MandelKit: the absolute value in the iteration breaks the symmetry of the classic Mandelbrot map.Image: Björn Kindler / MandelKit · MandelKit · Eigene Darstellung · Own work

The defining fold

A common definition iterates zₙ₊₁ = (|Re zₙ| + i|Im zₙ|)² + c from zero. The absolute values fold all quadrants before the nonlinear map acts, removing the holomorphic structure used in classical complex dynamics.

Before squaring, the real and imaginary components are reflected through absolute value. This non-holomorphic fold breaks the rotational relations of the classical quadratic family and creates the characteristic upright silhouette. Absolute values must be applied in the defined order; applying them after squaring gives another system. A seemingly minor shader refactor can therefore render a similarly named but mathematically different fractal.

Ships, masts and western filaments

The familiar view is often reflected vertically so the main form resembles a burning vessel. Deep regions contain repeating ship-like forms, towers and turbulent filaments, with visual structure concentrated differently from the Mandelbrot set.

The large “ships” sit in a landscape of narrow masts and westward filaments. Interesting deep locations often lie at negative imaginary coordinates and require high iteration limits because of long orbits. Rectangular artifacts there are not a property of the set; they usually reveal precision, tiling or preview defects. Higher-accuracy reference renders should continue the same filaments smoothly.

Deep zoom still needs precision

Block-shaped regions at high magnification are not an expected endpoint of Burning Ship geometry. They usually indicate insufficient coordinate precision, an unreliable perturbation approximation or an unfinished low-resolution pass. Correct rendering must continue to screen-matched detail.

Absolute-value operations do not remove the numerical challenges of deep zooms. Their non-analytic branching can make derivative and perturbation methods harder. A robust renderer tracks sign behavior along the reference orbit or falls back to more accurate direct iteration when uncertain. Visible quality must not depend on accidentally extending an unsuitable Mandelbrot approximation.

Sources and further reading

This article summarizes the following specialist sources in original wording. Accessed and editorially reviewed 12 August 2026.

  1. The Burning Ship and Its Quasi-Julia SetsComputers & Graphics
  2. Mandelbrot SetWolfram MathWorld