Emergent Impossible Fractal Geometry

A 4-State Cellular Automaton on Triangular Tessellations

A 4-state cellular automaton with 78 transition rules over a 7-cell neighborhood. When rendered on a triangular tessellation, its output is perceived as impossible 3D fractal geometry under isometric projection. Among its outputs is the Selmi triangle, a fractal Penrose tribar with self-similar structure at every scale.

Presets: The original rule set is Selmi (2009), producing the fractal Penrose tribar. Kitaoka 2010 and Selmi (2019) are variants with different beam crossing behavior. Right Stairs produces a descending staircase of impossible cubes. The remaining presets generate non-interacting geometric primitives (single beams, cubes, ladders).

How to use: Press Generate to run the automaton. Edit the Init string to change the seed (W=white, R=red, G=green, B=blue). Adjust Rows to control evolution depth. Hover over any triangle to inspect its neighborhood and matching rule. Click a triangle to load its rule into the editor. Use Export to download the output as SVG.
Init:
Rule: 78 rules