Snowflake Dendritic Growth (2D) — Ice Crystal Habit Simulator

Atmospheric Conditions

Temperature -15.0°C

Supersaturation 60%

Attachment sharpness γ 0.75

Growth speed 3

Current Habit (Nakaya diagram)

Growth regime

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Frozen cells

Arm count (est.)

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How it works

This is a simplified 2D top-down version of the same diffusion-limited growth physics used in the 3D engine, not a flat reprojection of it: it runs its own lighter hexagonal automaton (plain neighbor-averaged diffusion, no reflecting-boundary term) and represents habit purely through fill pattern instead of 3D height — a solid pale hex for a plate-like site, a thin bright core for a needle/column site, and a soft glow for a fast-freezing dendrite tip.

Vapor deposits onto the hexagonal ice lattice fastest where the diffusing field is least depleted — near sharp tips reaching into fresh vapor — so any small bump grows faster than its surroundings and the crystal edge becomes unstable and branches. Temperature moves you through the real Nakaya habit bands (plates near 0°C and -15°C, needles/columns near -5°C and below -22°C); supersaturation controls how strongly that branching instability wins over smooth faceted growth.

Drag the crystal to pan, scroll to zoom.
Click the ice to seed a second nucleus and watch two crystals compete for the same vapor.

Drag to pan · scroll to zoom · click ice to seed a new nucleus

Snowflake Dendritic Growth — 2D Ice Crystal Habit Simulator