Terrain and landscape

your project so far

Assets/

Scenes/

Arena.unity

FloorBlocks (parent)KnightTerrain

Scripts/

TerrainPlacer.cs

Prefabs/

Knight prefabEnemy.prefab

Materials/

terrain layers

all your scripts

you already havethis lesson adds

Arena.unity is still a grey box with your characters in it. This tab builds the world around it — around the arena you already have, not in place of it.

1
Open Assets/Scenes/Arena.unity — the same file you have used since tab 01. Do not make a new scene: the floor, the blocks, the characters, the enemies and the camera rig all stay.
2
Press Play before you touch anything. The Knight should walk, jump and cast exactly as it did at the end of tab 03.
3
Do not rebuild anything. If pressing Play does not let you walk around, fix that before you sculpt a single hill.

Terrain is a single optimised mesh driven by a heightmap. You paint the height with a brush instead of modelling hills by hand.

animated diagram

The brush raises the heightmap; the mesh follows underneath it.

Create the terrain

1
GameObject▸3D Object▸Terrain. A flat 1000×1000 m slab appears at the origin.
2
That is far too big for one arena. In the Terrain Settings gear, set Terrain Width and Length to 200.
3
Set Heightmap Resolution 513 and Detail Resolution 512 — plenty for a small level and much lighter.
4
Move the terrain to -100, -0.05, -100. Its centre lands under the arena, and its surface sits just below the tab 01 floor, so the two never flicker against each other.

The five tools in the toolbar

Raise or Lower Terrain — left click raises, Shift + left click lowers. Start with a big soft brush at low opacity.
Set Height — click to flatten everything to an exact height. This is how you make a buildable plateau.
Smooth Height — removes the spiky noise your brush leaves behind. Use it constantly.
Paint Texture — layers of ground material: grass, rock, sand, path.
Paint Trees and Paint Details — trees are prefabs, details are grass billboards.

Painting layers

1
Paint Texture → Edit Terrain Layers → Create Layer. The first layer covers the whole terrain.
2
Set each layer's Tiling Size to 8–15 metres. The default of 2 makes an obvious repeating pattern.
3
Add a rock layer and paint it only on the steep slopes; add a path layer with a small hard brush.
4
Four layers maximum on mobile. Each layer is another texture sample per pixel.

Trees, grass and the wind

Trees painted with the Terrain tool get automatic billboarding at distance — far cheaper than placing prefabs by hand.
Set Tree Distance about 120 and Billboard Start about 60 in the Terrain Settings.
Grass is a Detail Mesh or a Grass texture. Detail Distance 40 on desktop, 20 or less on mobile.
A Wind Zone (GameObject > 3D Object > Wind Zone) makes trees and grass sway. One is enough for a whole level.

Reading terrain height from code

place anything on the ground

using UnityEngine;

public class TerrainPlacer : MonoBehaviour
{
    [SerializeField] private GameObject prefab;
    [SerializeField] private int count = 60;
    [SerializeField] private float area = 90f;

    void Start()
    {
        Terrain terrain = Terrain.activeTerrain;

        for (int i = 0; i < count; i++)
        {
            float x = Random.Range(-area, area);
            float z = Random.Range(-area, area);

            // exact ground height at that world position
            float y = terrain.SampleHeight(new Vector3(x, 0f, z)) + terrain.transform.position.y;

            Quaternion rot = Quaternion.Euler(0f, Random.Range(0f, 360f), 0f);
            Instantiate(prefab, new Vector3(x, y, z), rot, transform);
        }
    }
}