Terrain: ground surfaces

When to use Terrain

Terrain is the built-in ground-surface object: heights, textures, vegetation, collisions and navigation. It requires no project addon. Data is divided into regions; clipmap LOD reduces distant detail.

Each X/Z position stores one surface height. Use Voxel Tools or separate meshes for caves, overhangs and volumetric destruction. A Terrain hole removes part of the surface; it does not generate cave walls.

The Terrain interface is still being refined. Instructions below use object and property names; button placement may change. Start material work in Forward+ or Deferred and verify the chosen renderer on your target platform.

Create the first region

1. Add a Terrain object to a 3D scene.
2. Set Data Directory to a project folder, such as asset://World/TerrainData. Regions are stored separately from the scene file.
3. Check that TerrainMaterial and TerrainAssets resources are assigned.
4. Add one region with the region tool. An empty Terrain object without regions is not a finished ground surface.
5. Choose a height tool and set brush size and strength. Modify a small area, then smooth the boundary.
6. Save both Terrain data and the scene. Reopening should retain the same surface.

Establish the scale of one region before expanding the world. Vertex Spacing controls the distance between vertices: a larger spacing lowers detail density in world units. Region size and LOD do not replace scale settings.

Materials and painting

Add ground textures to TerrainAssets. Configure each layer's albedo, normal map, scale and material parameters. Import normal maps as normal data, rather than color images.

Paint a small area with a selected layer. Inspect it nearby and at a distance: excessive scale stretches rocks, while tiny scale produces repetition and noise. Tools include texture blending, rotation, color, roughness and automatic terrain materials.

Establish texture scale first, then adjust transitions and automatic blending. One calibrated layer is more useful than many untested materials.

Sculpting and heightmaps

Use sufficient height precision in the source heightmap. An ordinary 8-bit image can produce terraces across a large elevation range. Check dimensions, position, vertical range and neighboring regions when importing. Heightmap export preserves elevations, not a complete scene with materials and vegetation.

Collisions, vegetation and navigation

Collision Mode selects collision generation for the game, editor or neither. If a character falls through the ground, first check that mode and matching collision layers/masks. Visible geometry does not prove that a physics shape exists.

Place vegetation with the Terrain instancer or separate prepared prefabs. Check model scale, shadows, LOD and density. Keep decoration off surface types where it should not grow.

Navigation painting identifies allowed areas; it does not make NPCs move by itself. Prepare navigation data and test an agent's path. Collision geometry, the visible surface and navigation serve different purposes.

Saving, export and troubleshooting

The native export integration includes region data. Keep it inside the project and inspect the exported build separately from the editor. Copying only the scene file is insufficient to share the terrain.

Mesh baking produces surface geometry for a specific task; it does not replace the editable source regions. Retain source data for future sculpting.