Reaction Diffusion simulation of two virtual chemicals using Blender 4.2+ geometry nodes simulation

Free version available here

Reaction diffusion solver based on Gray-Scott model. More info about the Gray-Scott model

A - Chemical A value stored on the mesh (set to 1)
B - Chemical B value stored on the mesh (set it to some random texture/noise that effect will growth from)
K - Chemical kill rate
F - Chemical Feed rate
Da/Db - Bigger value will make pattern a slightly bigger, smaller value slightly smaller. Note that value range should be from 0.19 to 0.4, otherwise simulation will not work.
Scale - Scale up the pattern

Different K and F values:

To find more K and F values visit online reaction diffusion simulation - Karl Sims web reaction diffusion simulation

Included Marching Squares/Triangles algorithm nodes for creating isolines and cut surface from reaction diffusion pattern

Marching Squares/Triangles documentation - https://higgsas-geo-nodes-manual.readthedocs.io/en/latest/generators.html

Included files :

Included files for paid version:

reaction_diffusion_simple_example.blend

reaction_diffusion_mutiple_patterns_mix.blend

reaction_diffusion_marching_squares_triangles.blend

reaction_diffusion_vase_example.blend

Reaction Diffusion Asset.zip

Adding reaction diffusion solver to asset browser:

1. Unzip Reaction Diffusion Asset.zip file

1. Add Reaction Diffusion Asset.blend and blender_assets.cats to your blender asset browser folder (\\Documents\Blender\Assets)

All nodes (Reaction diffusion and marching squares/triangles) included in Higgsas Geometry Nodes Toolset

2025-05-29 Update

Updated to blender 4.2 version added Direction Reaction Diffusion node.

Contact info:

Email - [email protected]
Twitter - https://twitter.com/higgsasxyz
Instagram - https://www.instagram.com/higgsas/