A Geometry Nodes setup for simulating reaction-diffusion systems in Blender. The tool uses mathematical models to generate complex organic patterns, such as animal stripes or cellular growth, across mesh surfaces. Users can visualize the simulation using included 2D rendering and displacement utilities. An interactive brush object allows for local manipulation by erasing the simulated substances. The system includes parameters for controlling simulation sub-steps and diffusion rates, with calculation resolution dependent on the base mesh density.