Rules-based Terrain
The world is not simply a randomly colored map. It begins with geographically coherent elevations—hills, valleys, islands, coastlines, basins, and other landforms—then evolves through interactions among water, weather, soil, vegetation, and occasional disturbances.
Every tile has properties beneath its visible symbol. Elevation affects drainage and temperature. Soil moisture affects which plants can grow. Vegetation influences the ground beneath it, while floods, erosion, fire, and other processes can alter the conditions that originally supported it.
These relationships make the simulation partly predictable and partly surprising. Its rules are simplified, but the consequences can unfold in combinations that were never designed as individual, scripted scenes.
What happens in the simulated world?
Terrain, water, and erosion
Water enters through rainfall, snowmelt, and springs; it can flow downhill, collect in depressions, enter the soil, seep from shallow groundwater, or evaporate. Moving water can gradually erode the ground and transport sediment, which may settle elsewhere. Lakes, streams, marshes, riverbanks, and coastal environments arise from combinations of elevation and water conditions.
The ocean has a prescribed sea level, while inland freshwater is handled separately. Freezing temperatures can produce snow and surface ice. In the three-dimensional view, water is drawn above the terrain, and you can reduce its opacity to examine the seabed underneath.
Climate and seasons
Latitude, temperature, precipitation, elevation, and prevailing winds influence the environment. Seasonal changes can produce snow, thawing, periods of increased or reduced moisture, and visible changes in suitable deciduous-looking woodland. Terrain affects how moisture-bearing winds distribute rain, producing wetter and drier slopes.
Plants, fungi, and habitat changes
Grasslands, scrub, woodland, forests, wet meadows, bogs, swamps, and other habitats appear where conditions support them. Vegetation grows, competes, spreads, declines, or recovers depending on climate, soil, water, and disturbance. Rare damp fungal patches can establish in suitable places, while peat slowly accumulates in some persistently wet ground and influences moisture retention. You may even see some special, rare terrain features, or even animals that influence the ecology!
Landscapes are not assigned permanent biome labels. A wet meadow can dry out; a flood can damage woodland; a burned patch can recover. The visible habitat classification is an interpretation of the tile's current state.
Disturbances and exceptional conditions
Some worlds experience fires, floods, and other localized stresses. Volcanic-island worlds can produce eruptions: lava moves across the landscape, damages vegetation, and eventually cools into new rocky ground. These events are modeled with simplified environmental rules, rather than a full geological or meteorological engine, and they sure are fun to watch.
Generate a world, then mess with it
Begin with a landscape preset such as an archipelago, river delta, mountain valley, fjords, canyon country, volcanic island, or a Driftless-inspired region of branching ridges and valleys. Each preset suggests a set of starting conditions, including ruggedness, latitude, rainfall, and temperature; these can be changed independently before generation.
World seeds create repeatable starting configurations. Changing the seed produces another variation of the selected geography. Different climates applied to the same kind of terrain can lead to very different vegetation and water conditions.
Intervene
Pretend you're a god. Dig trenches, raise ground, add or drain freshwater, create springs, plant trees or grass, clear vegetation, and ignite fires. You can also change the existing world's temperature, rainfall, latitude, or wind direction. These interventions change environmental conditions—not simply the color of a tile.
Observe
Pause, step forward, or accelerate simulated time. Switch map layers to examine elevation, surface water, groundwater, moisture, temperature, vegetation, or rainfall potential. The tile inspector explains a site's conditions and why its current habitat is present. Individual tiles can be watched as the world evolves.
A few experiments to try
Redirect a stream
Dig a low channel from an existing water source toward a depression. As water moves and collects, nearby soil may become wetter, waterlogged vegetation may appear, and deposited sediment can eventually influence drainage. The result depends on the elevations and the amount of incoming water.
Change the climate
Cool a landscape and move through its seasons. Higher ground may accumulate snow, some water may freeze, and later thawing can feed surface water. Or lower the rainfall and see how vegetation responds as soil moisture changes.
Introduce a disturbance
Ignite a dry patch of vegetation and watch how local moisture, fuel, wind, and slope affect its spread. After the fire, the underlying land remains, but its vegetation and recovery conditions are different.
Follow a volcanic island
Start with a volcanic-island preset and inspect its central peak and radial slopes in three dimensions. Trigger an eruption or wait for volcanic activity, then observe where lava travels and how the cooled deposits change the terrain.
These are possibilities rather than guaranteed outcomes. The simulation responds to its current state, chosen settings, and stochastic events. You never know what exactly might happen next!
Two ways to explore the same world
2D symbolic map
The default view is a large, zoomable grid made from colored cells and typographic symbols. Pan, zoom, inspect, or edit the terrain, and open the controls only when you need them. On touch devices, one finger can select or use a brush, while two fingers can pan and pinch-zoom.
Interactive 3D terrain
Switch to a rotatable three-dimensional representation of the same landscape. The 3D model retains its color-coded tiles and symbols, and offers camera rotation, travel, vertical movement, an XYZ orientation indicator, and adjustable vertical exaggeration. You can reveal underwater elevation by making the blue water surface transparent.
The 3D view opens paused, but you can resume simulated time and see periodic updates to the landscape while exploring. Mouse and keyboard navigation are available on desktop, and touch gestures are supported on mobile. The tile inspector works in both views.
A quick guide to the symbols
The map's colors and glyphs indicate broad landscape conditions. Some symbols vary by habitat, season, and tile; some are slightly different colors just for flavor. These are a few recurring examples, not a complete legend.
Inspect any tile to see its actual name, elevation, water, soil, and climate readings. A symbol is a compact visualization, not the complete scientific state of that tile. Hover over the name of any tile on the inspect screen to learn more about that habitat itself.
Common questions
Is Ecosystem Explorer a game?
It's primarily an experimental sandbox and generative artwork, not a game with missions or victory conditions. You can simply watch a world develop, or deliberately alter it and investigate the results.
Does it accurately simulate Earth?
No. The model uses simplified, physically and ecologically motivated rules rather than scientifically calibrated fluid dynamics, atmospheric circulation, hydrology, or species-level biology. Some features are approximations, and simulated time and scales are compressed for playability. It is not a forecasting, engineering, or educational validation tool.
Is every landscape different?
Landscape presets define broad geographic families; seeded generation varies the terrain within those families. Random environmental events and the user's own changes can produce further differences. A seed can reproduce starting conditions under the same version and settings, though generation algorithms may change between releases.
Can I save a world?
Yes. You can save locally in the browser or export a portable world file and import it later. Older saved-world formats are supported where practical, but very old software releases may not open newer saves.
Do I need to install anything?
No. The simulation runs in a modern browser with JavaScript enabled. The three-dimensional terrain viewer additionally requires WebGL2 support. The project does not depend on a remote simulation service.
Where do the images come from?
Referring to the images used for the backgrounds of the Inspect Tile screen, almost all of the images are public domain and sourced from Pixabay. However, there are a small number of images that require special attribution:
Original uploaded by Nationalparks (Transferred by Nihonjoe), CC BY-SA 2.5, via Wikimedia Commons
en:user:Mikenorton, CC BY-SA 3.0, via Wikimedia Commons
About the project and its inspiration
Ecosystem Explorer was created by Ethan J. Hulbert as an experiment in environmental systems, procedural art, and the unexpected complexity that can emerge from simple interacting rules.
This project was originally inspired by Permaculture Network, an ecological simulation project by Gary Zhexi Zhang and Agnes Cameron based at Sakiya. Its use of symbols and interrelated environmental agents helped inspire the idea of a living landscape expressed through a grid.
Ecosystem Explorer is a separate project with its own simulation design, world generation, editing tools, and two- and three-dimensional interfaces. No code was actually taken or reused.
Interested in seeing what a tiny intervention can do to an entire watershed? Return to Ecosystem Explorer and make a world.