Modify terrain through code/script

Questions & Answers
1

Hi,

anybody could please tell me what am i doing wrong in here? is there some setting in the terrain object im missing?

im trying to run this example code in JS:

this is what i get:

12242-terrain.png
12242-terrain.png1920×1080 234 KB

if instead if run this code nothing happen at all:

using UnityEngine;
using System.Collections;

public class NewBehaviourScript : MonoBehaviour {

Terrain terr; // terrain to modify
int hmWidth; // heightmap width
int hmHeight; // heightmap height
 
void Start () {
 
	terr = Terrain.activeTerrain;
	hmWidth = terr.terrainData.heightmapWidth;
	hmHeight = terr.terrainData.heightmapHeight;
 	Terrain.activeTerrain.heightmapMaximumLOD = 0;
}
 
void Update () {
 
	// get the heights of the terrain under this game object
	float[,] heights = terr.terrainData.GetHeights(0,0,hmWidth,hmHeight);
 
	// we set each sample of the terrain in the size to the desired height
	for (int i=0; i<hmWidth; i++)
		for (int j=0; j<hmHeight; j++){
			heights[i,j] = 1000;
			//print(heights[i,j]);
 		}
	// set the new height
	terr.terrainData.SetHeights(0,0,heights);
 
}
}
2

> heights[i,j] = 1000;

Both GetHeights and SetHeights use normalized height values, where
0.0 equals to terrain.transform.position.y in the world space and 1.0 equals to terrain.transform.position.y + terrain.terrainData.size.y in the world space

So, change 1000 to something between 0 and 1.

Notice, however, that terrainData.GetHeight returns a value already multiplied by terrain.terrainData.size.y.

3

@åperture
the code works great if you use Random.Range(0f,0.01f);
per below
which can be used one time in start, or continual in update

using UnityEngine;
using System.Collections;

public class NewBehaviourScript : MonoBehaviour
{

Terrain terr; // terrain to modify
int hmWidth; // heightmap width
int hmHeight; // heightmap height

void Start()
{

    terr = Terrain.activeTerrain;
    hmWidth = terr.terrainData.heightmapResolution;
    hmHeight = terr.terrainData.heightmapResolution;
    Terrain.activeTerrain.heightmapMaximumLOD = 0;
//}

//void Update()
//{

    // get the heights of the terrain under this game object
    float[,] heights = terr.terrainData.GetHeights(0, 0, hmWidth, hmHeight);

    // we set each sample of the terrain in the size to the desired height
    for (int i = 0; i < hmWidth; i++)
        for (int j = 0; j < hmHeight; j++)
        {
            heights[i, j] = Random.Range(0.0f, 0.01f);
            //print(heights[i,j]);
        }
    // set the new height
    terr.terrainData.SetHeights(0, 0, heights);

}

}