using System;
using UnityEngine;
using Random = UnityEngine.Random;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
public class CreateRandomObjects : MonoBehaviour
{
public GameObject ObjectToCreate;
public int spaceshipsStartingHeight = 3;
[HideInInspector]
public GameObject[] objects;
// for tracking properties change
private Vector3 _extents;
private int _objectCount;
private float _objectSize;
private List<int> randomNumbers = new List<int>();
/// <summary>
/// How far to place spheres randomly.
/// </summary>
public Vector3 Extents;
/// <summary>
/// How many spheres wanted.
/// </summary>
public int ObjectCount;
public float ObjectSize;
// Use this for initialization
void Start()
{
Clone();
objects = GameObject.FindGameObjectsWithTag("ObjectToClone");
}
private void OnValidate()
{
// prevent wrong values to be entered
Extents = new Vector3(Mathf.Max(0.0f, Extents.x), Mathf.Max(0.0f, Extents.y), Mathf.Max(0.0f, Extents.z));
ObjectCount = Mathf.Max(0, ObjectCount);
ObjectSize = Mathf.Max(0.0f, ObjectSize);
}
private void Reset()
{
Extents = new Vector3(250.0f, 20.0f, 250.0f);
ObjectCount = 100;
ObjectSize = 20.0f;
}
// Update is called once per frame
void Update()
{
}
private void Clone()
{
if (Extents == _extents && ObjectCount == _objectCount && Mathf.Approximately(ObjectSize, _objectSize))
return;
// cleanup
var ObjectsToDestroy = GameObject.FindGameObjectsWithTag("ObjectToClone");
foreach (var t in ObjectsToDestroy)
{
if (Application.isEditor)
{
DestroyImmediate(t);
}
else
{
Destroy(t);
}
}
var withTag = GameObject.FindWithTag("Terrain");
if (withTag == null)
throw new InvalidOperationException("Terrain not found");
for (var i = 0; i < ObjectCount; i++)
{
var o = Instantiate(ObjectToCreate);
o.tag = "ObjectToClone";
o.transform.SetParent(base.gameObject.transform);
o.transform.localScale = new Vector3(ObjectSize, ObjectSize, ObjectSize);
// get random position
var x = Random.Range(-Extents.x, Extents.x);
var y = Extents.y; // sphere altitude relative to terrain below
var z = Random.Range(-Extents.z, Extents.z);
// now send a ray down terrain to adjust Y according terrain below
var height = 10000.0f; // should be higher than highest terrain altitude
var origin = new Vector3(x, height, z);
var ray = new Ray(origin, Vector3.down);
RaycastHit hit;
var maxDistance = 20000.0f;
var nameToLayer = LayerMask.NameToLayer("Terrain");
var layerMask = 1 << nameToLayer;
if (Physics.Raycast(ray, out hit, maxDistance, layerMask))
{
var distance = hit.distance;
y = height - distance + y; // adjust
}
else
{
Debug.LogWarning("Terrain not hit, using default height !");
}
//o.transform.Rotate(0.0f,randomNumbers[i],0.0f);
// place !
o.transform.position = new Vector3(x, y + spaceshipsStartingHeight, z);
}
_extents = Extents;
_objectCount = ObjectCount;
_objectSize = ObjectSize;
}
}
Some of the objects created are out of the terrain area.
I want that the objects will be created in random positions but only inside the terrain area.
A side question, If someone can explain please this part of the code. What does it do and mean ?
var height = 10000.0f; // should be higher than highest terrain altitude
var origin = new Vector3(x, height, z);
var ray = new Ray(origin, Vector3.down);
RaycastHit hit;
var maxDistance = 20000.0f;
var nameToLayer = LayerMask.NameToLayer("Terrain");
var layerMask = 1 << nameToLayer;
if (Physics.Raycast(ray, out hit, maxDistance, layerMask))
{
var distance = hit.distance;
y = height - distance + y; // adjust
}