Overview
Introduction
Most Sierpinski-style square fractals are built on the carpet's 3x3-minus-center rule. This tool takes a different, simpler approach, split each square into just 4 quadrants and drop one of them, repeated recursively.
The result is a self-similar, L-shaped fractal rather than the carpet's centered, symmetric hole pattern, and it's our own square-based variant rather than a reproduction of the classical carpet.
What Is Generate a Sierpinski Square?
A recursive square fractal generator that subdivides each surviving square into a 2x2 grid of quadrants and removes one specific quadrant at every level.
It shares the same recursive spirit as the Sierpinski carpet, subdivide and remove, but with a different grid size and removal pattern, producing a visually distinct L-shaped silhouette instead of the carpet's centered lattice.
How Generate a Sierpinski Square Works
Starting from a single square, the tool splits it into a 2x2 grid of four equal quadrants and discards one fixed quadrant, keeping the other three.
Each of the three surviving quadrants is then recursively split the same way, into 4 sub-quadrants with one dropped, down to the chosen Depth.
Because the same quadrant position is dropped at every level and every scale, the overall silhouette accumulates into an L-shaped, self-similar outline rather than a centered hole pattern.
When To Use Generate a Sierpinski Square
Use it when you want a square-grid fractal with an asymmetric, L-shaped character, for generative art, geometric backgrounds, or teaching recursive subdivision with a simpler 2x2 rule than the carpet's 3x3.
If you specifically need the classical, centered Sierpinski carpet pattern, use a carpet generator instead, this tool's quadrant-drop rule produces a different shape.
Often used alongside Generate a Sierpinski Maze, Generate a Sierpinski Hexagon and Generate a Sierpinski Pentagon.
Features
Advantages
- Simple 2x2 subdivision rule that's easy to follow visually, even at higher depth.
- Supports Depth up to 8, well beyond the 3x3-grid tools, since each level only quarters the surviving squares.
- Filled-square rendering makes the recursive structure easy to read at a glance.
Limitations
- Not the classical Sierpinski carpet, if you need that exact centered construction, this L-shaped variant isn't a substitute.
- The self-similarity is directional (always the same quadrant dropped), so the fractal isn't rotationally symmetric the way the carpet is.
Examples
Best Practices & Notes
Best Practices
- Start around Depth 3-4 to see the L-shaped structure clearly before pushing toward the higher end of the range.
- Use the SVG export if you plan to recolor the filled squares or extract them as separate shapes later.
Developer Notes
The geometry reuses the shared `subdivideGrid` helper with `gridSize = 2` and a `keep(row, col)` predicate that drops one fixed quadrant (row 0, col 1), unlike the carpet/maze tools which pass `gridSize = 3` and drop only the center cell. Because the sub-cell count only grows by a factor of 3 per level (3 kept of 4) rather than 8 of 9, `boundsCheck` allows Depth up to 8 here instead of 4.
Generate a Sierpinski Square Use Cases
- Generative art and geometric background patterns with an asymmetric fractal silhouette
- Teaching recursive subdivision using a simpler 2x2 rule before introducing the carpet's 3x3 rule
- Comparing subdivision strategies against the carpet-based Sierpinski Maze Generator
Common Mistakes
- Assuming this produces the same shape as the classic Sierpinski carpet, the 2x2 quadrant-drop rule gives a different, L-shaped result.
- Setting Depth too high too quickly, the squares shrink fast and the structure can become hard to distinguish visually past depth 6 or 7 at typical viewing sizes.
Tips
- Compare this tool against Sierpinski Maze Generator at the same conceptual depth to see how a 2x2 versus 3x3 subdivision rule changes the resulting silhouette.
- Lower the Depth if you're exporting for a small thumbnail, the finest detail only matters at larger render sizes.