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Terrain Generator

The Terrain Generator fills your grid with procedurally generated terrain in one tap — hills and valleys shaped by fractal noise, biome-appropriate materials, optional ocean and lake water, and experimental cave systems. Every generation is unique. Find it in the sidebar, just below the Resize button in the Grid Size section.

Opening the Terrain Generator

Tap Terrain Generator in the sidebar (below the Resize button in the Grid Size section). A panel opens with all generation options. You can also set your desired grid dimensions inside the panel before generating — the generator resizes the grid to match when you tap Generate, so you don't need to resize manually first.

Generation Method

Two buttons at the top of the panel — Random and Volcano — set the overall shape of the terrain before you choose a biome or any other option.

Random

The default method. Produces rolling hills and valleys across the full grid using fractal noise. The Height Variation slider controls how dramatic the elevation changes are. Every generation is different — the noise seed is randomised on each press of Generate.

Volcano

Places a single conical mountain centred exactly on the grid. The base fills the entire grid footprint (every column has a height of at least 1), and the sides taper upward using a smooth quintic falloff. Fractal noise is layered over the cone to break the perfect symmetry and give the slopes an eroded, natural appearance rather than a uniform shape.

A caldera is carved at the summit: the rim stands at the mountain's peak height while the centre is scooped into a bowl using a concave ease curve, producing a realistic volcanic crater shape. The caldera radius and depth are calculated automatically relative to the grid size.

Material layering on a Volcano is altitude-aware. Below roughly 60% of the mountain's peak height, the normal biome layer stack applies (grass cap, then soil, then rock). Above that threshold the terrain switches to bare rock only — no grass, no soil — so the upper slopes and summit look naturally barren. The rock variants used are still those of the chosen biome preset, so the overall colour palette stays consistent.

Biome Preset

Choose a biome preset to set the visual theme of the terrain. Each preset selects a matching grass type, soil material, and rock variants — the shape of the terrain is determined by the generation method, not the biome, so the same grid looks different in each preset.

Terrain Height

The Height Variation slider (0–20) controls the amplitude of the terrain noise — how much the surface rises and falls between its lowest and highest points.

• 0: Perfectly flat. Every column is the same height — useful as a blank canvas.
• 1–5: Gentle rolling hills with modest elevation changes.
• 6–10: Noticeable hills and valleys; good general-purpose terrain.
• 11–20: Dramatic peaks and deep depressions. Very high values can produce near-vertical cliff faces and deep gorges.

The noise also enforces a maximum 3-block step between neighbouring columns so terrain always stays smooth and climbable rather than spikey, regardless of how high the slider is set.

Water

Ocean

Enable Ocean to flood one or two sides of the grid with sea water at a fixed sea level. The intensity slider (1–10) controls both how high the sea level sits and how many sides are affected:

• Intensity 1–5: One randomly chosen side is flooded. Sea level sits at roughly 20–40% of grid height — only the lowest coastal depressions go under.
• Intensity 6–10: Two randomly chosen sides are flooded. Sea level rises to roughly 40–55% of grid height — a wider coastal shelf is submerged.

Terrain columns that rise above sea level stay completely dry, forming natural cliffs, headlands, and coastlines. Submerged columns are filled with sea water from their terrain surface up to sea level, so deeper areas have deeper water. The ocean uses the Sea Water liquid type.

Lakes / Rivers

Enable Lakes / Rivers to add fresh water after the terrain is generated. The generator scans the terrain for natural low points (depressions where every neighbouring column is higher) and seeds lakes there. The intensity slider (1–10) controls how many lakes appear:

• Intensity 1–4: 1–2 lakes placed in the deepest natural basins. No rivers.
• Intensity 5–10: Up to 5 lakes, plus 1–3 rivers. Rivers cascade from a randomly chosen highland point and flow downhill under the game's full liquid physics.

Lakes and rivers use the Fresh Water liquid type. If Ocean is also enabled, fresh water bodies will only appear on terrain above sea level.

Caves (Experimental)

Enable Caves to carve tunnels and caverns through the solid terrain using 3D fractal noise. The cave mask carves where the noise field passes through integer-level sets, producing organic branching tunnels that don't grid-align.

Density

Controls how much of the terrain interior is hollow. Higher values carve more void — at very high densities the terrain can become more air than rock. The slider maps to a noise threshold from roughly 8% void at density 1 to 29% at density 10.

Cave Size

Controls the scale of the tunnels and caverns. Low values (1–3) produce tight, winding passages. High values (7–10) open up wide caverns and large interconnected chambers.

How caves are cleaned up

After carving, the generator runs three clean-up passes automatically:

1. Surface entrances: A number of shafts are punched through the grass cap so caves are visible and reachable from above. Without this, caves would be entirely hidden underground.
2. Floating chunk removal: Any solid block group with no path to the ground floor (Y=0) via connected solid neighbours is deleted. This removes mid-air islands that can appear above carved voids.
3. Water cascade: Any water block whose supporting terrain was carved away drops to the nearest solid cave floor below it, so lakes don't levitate above cave voids.

Grid Size & Generating

The Width (X), Height (Y), and Length (Z) sliders inside the Terrain Generator panel are linked to the main Grid Size controls in the sidebar — changing either set updates the other. Set your desired dimensions here before generating so you don't have to close the panel and resize separately.

When you're ready, tap Generate. The generator will:

1. Resize the grid to your chosen dimensions.
2. Clear your entire current build.
3. Fill the grid with the new terrain, water, and caves.
4. Re-render the viewport.

Generation is instant for typical grid sizes (up to around 50×50). Very large grids with caves enabled may take a moment longer due to the floating-chunk removal flood fill.