please explain Terrain.SetHeights

Questions & Answers
1

I'm trying to set terrain heights by code but i just don't get the Terrain.SetHeights command. Can someone please explain it so even a noob can understand it (best with example)? There are NO examples in the code reference...

How can I create the needed attribute "float[,]"?? Is it even possible via javaScript? I read somewhere that this can only be done in C#, but I thought that the programming language doesn't matter in Unity...

I could get the current heights via Terrain.GetHeights. How can I now edit these settings?

3

I got it now, Here's a test script to randomize heights and reset them, with buttons. Attach the script to the Terrain:

var terrain : Terrain;
var tData : TerrainData;

var xRes : int;
var yRes : int;

var heights : float[];

function Start () {
    terrain = transform.GetComponent(Terrain);
    tData = terrain.terrainData;

    xRes = tData.heightmapWidth;
    yRes = tData.heightmapHeight;

    terrain.activeTerrain.heightmapMaximumLOD = 0;

}

function OnGUI() {

    if(GUI.Button (Rect (10, 10, 100, 25), "Wrinkle")) {
        randomizePoints(0.1);
    } 

    if(GUI.Button (Rect (10, 40, 100, 25), "Reset")) {
        resetPoints();
    } 
}

function randomizePoints(strength:float) {
    var heights = tData.GetHeights(0, 0, xRes, yRes);

    for (y = 0; y < yRes; y++) {
        for (x = 0; x < xRes; x++) {
            heights[x,y] = Random.Range(0.0, strength) * .5; 
        }
    }

    tData.SetHeights(0, 0, heights);
}

function resetPoints() {
    var heights = tData.GetHeights(0, 0, xRes, yRes);

    for (y = 0; y < yRes; y++) {
        for (x = 0; x < xRes; x++) {
            heights[x,y] = 0; 
        }
    }

    tData.SetHeights(0, 0, heights);
}
4

This is the same code in C#, for those interested:

using UnityEngine;
using System.Collections;

public class RandomizeHeights : MonoBehaviour {

	Terrain  terrain; 
	TerrainData tData;
	
	int xRes;
	int yRes;
	
	float[,] heights;
	
	void Start () { 
		terrain = transform.GetComponent<Terrain>(); 
		tData = terrain.terrainData;
		
		xRes = tData.heightmapWidth;
		yRes = tData.heightmapHeight;
	}
	
	void OnGUI() {
		if(GUI.Button (new Rect (10, 10, 100, 25), "Wrinkle")) {
			randomizePoints(0.1f);
		}
		
		if(GUI.Button (new Rect (10, 40, 100, 25), "Reset")) {
			resetPoints();
		} 
	}
	
	void randomizePoints(float strength) { 
		heights = tData.GetHeights(0, 0, xRes, yRes);
		
		for (int y = 0; y < yRes; y++) {
			for (int x = 0; x < xRes; x++) {
				heights[x,y] = Random.Range(0.0f, strength) * 0.5f;
			}
		}
		
		tData.SetHeights(0, 0, heights);
	}
	
	void resetPoints() { var heights = tData.GetHeights(0, 0, xRes, yRes);
		for (int y = 0; y < yRes; y++) {
			for (int x = 0; x < xRes; x++) {
				heights[x,y] = 0;
			}
		}
		
		tData.SetHeights(0, 0, heights);
	} 

	// Update is called once per frame
	void Update () {
	
	}
}
2

it's possible, but you need a c# script to create the 2d array in the first place

What you can do is grab the MultiDimArray script from the wiki ( http://www.unifycommunity.com/wiki/index.php?title=JavascriptMultiDimArrays ), then fill int he values yourself

The array itself is basically similar to a greyscale texture - you set a 0->1 value for each item in it, and it maps to an x/y coordinate, e.g. yourArray[x,y] = 0.5;

If you just needed to grab the original heights and change them, you'd just use var by itself without a type, e.g. var heights = Terrain.activeTerrain.terrainData.GetHeights(0, 0, 10, 10); then access them as above