Spawning objects at random Vector3

Question

I've got some ammo pickups around my game map, working perfectly. Now all I need to do is get them spawning at random points at runtime. I thought to save problems with height, I'd spawn them up in the air, and let them fall and land on the terrain surface. The ammo boxes spawn fine, but all at 0, 0, 0. And I can't work out why.

 using UnityEngine;
 using System.Collections;
 
 public class ammoSpawn : MonoBehaviour {
 
     public Transform ammoDrop;
     public int numToSpawn;
     public Vector3 position;
     
     void Awake()
     {
         Vector3 position = new Vector3(Random.Range(100.0F, 1000.0F), 70, Random.Range(100.0F, 1000.0F));
     }
     
     void Start() 
     {
         int spawned = 0;
         
         while (spawned < numToSpawn)
         {
             spawned++;
             Instantiate(ammoDrop, position, Quaternion.identity);
         }
     }
     
 }

I know in this code, all will be spawned at one point, but why 0, 0, 0? Surely thats not right!

Answer 1

Best Answer Wiki

Answer by PaulUsul · Nov 26, 2012 at 06:39 PM

The trick is that the Random.Range generates random numbers every time you call it.

     void Start() 
     {
        int spawned = 0;
 
        while (spawned < numToSpawn)
        {
           position = new Vector3(Random.Range(100.0F, 1000.0F), 70, Random.Range(100.0F, 1000.0F));
           Instantiate(ammoDrop, position, Quaternion.identity);
           spawned++;
        }
     }

This way a new position is generated every time before you spawn the object.

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satnav_8 · Nov 27, 2012 at 05:04 PM 0

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Thanks, thats perfect!

Answer 2

Answer by flaviusxvii · Nov 26, 2012 at 07:03 PM

Your variable "position" in Awake() is shadowing the data member "position" of the class.

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Answer 3

Answer by Meltdown · Nov 26, 2012 at 06:40 PM

I'd suggest tagging all your spawnpoints with a tag called 'spawnpoint', then use GameObject.FindGameObjectsWithTag() to get all the spawn points in your scene.

Then use Random.Range() to choose one of those random spawn points in your scene to instantiate your game object at.

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vverma9 · Feb 21, 2017 at 08:08 AM 0

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and how would you ensure that the same spawn point is not selected again?

SarahU vverma9 · Feb 21, 2017 at 09:13 AM 0

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You can store Id of last selected spawn point and generate new ids until you generate a different one.

Spawning objects at random Vector3

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