Terragence
by Omry Damari · Four-Layer Procedural World Engine
Physics causes Chemistry. Chemistry causes Biology. Biology and Physics cause Sociology. Nothing is placed. Everything is caused.
01 · Physics — Thermodynamic Terrain
FBM Simplex noise generates the initial height field. Then the Fourier heat equation (∂T/∂t = α∇²T) diffuses it over 8 passes. High peaks emit heat that suppresses neighbouring heights — mountains carve their own valleys. Hydraulic droplet erosion refines the surface.
02 · Chemistry — Gray-Scott Reaction-Diffusion
Alan Turing's 1952 morphogenesis system, parameterised by Gray and Scott. Two chemicals A and B react: A+2B→3B. The terrain height seeds the initial concentrations — tall rock starts inhibitor-rich, low ground activator-rich. 60 iterations crystallise Turing patterns that become biome boundaries. No lookup table. Chemistry causes geography.
03 · Biology — Lorenz Attractor Trees
Each tree is a Lorenz trajectory. The system's three ODEs (σ=10, ρ=28, β=8/3) are integrated from initial conditions derived from world position. Sensitive dependence on initial conditions means two adjacent trees diverge completely — same species, different individual. 4 species: Oak, Pine, Mystic, Autumn.
04 · Sociology — Social Force Model
Helbing's 1995 pedestrian model, inverted to urban morphogenesis. Four zone types (Residential, Commercial, Industrial, Civic) emit Gaussian potential fields. A 4×4 interaction matrix encodes attraction and repulsion. Roads are not drawn — they are extracted as gradient ridges where competing zone influences meet.
Composition
World = S(B(R(T(seed)))) — every world is a deterministic function of a single integer. The output space of each equation is the input manifold of the next. Emergent complexity from composed simplicity.
Fourier 1822
Heat diffusion shapes raw noise into credible terrain
Turing 1952
Reaction-diffusion generates biome patch boundaries
Lorenz 1963
Strange attractor trajectories become tree canopies
Helbing 1995
Social forces and gradient ridges become roads and cities