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Game Development How to Make a Video Game Pickups Spawn Pickups Randomly

Joel Price
Joel Price
13,711 Points
Posted by Joel Price
Joel Price
13,711 Points

Flies no longer move nor respond to collision.

Just as the title says, my flies no longer fly around or get destroyed when my frog runs into them. I can't figure out what's going on for the life of me. Any help is appreciated!

FlySpawner code

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class FlySpawner : MonoBehaviour {

    [SerializeField]
    private GameObject flyPrefab;

    [SerializeField]
    private int totalFlyMinimum = 12;

    private float spawnArea = 25f;

    public static int totalFlies;

    // Use this for initialization
    void Start () {

        totalFlies = 0;

    }

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

        //While the total number of flies is < the minimum...
        while (totalFlies < totalFlyMinimum) {

            //...then increment the total number of flies
            totalFlies++;

            //...create a random position for a fly
            float positionX = Random.Range(-spawnArea, spawnArea);
            float positionZ = Random.Range(-spawnArea, spawnArea);

            Vector3 flyPosition = new Vector3 (positionX, 2f, positionZ);

            //...and create a new fly.
            Instantiate(flyPrefab, flyPosition, Quaternion.identity);

        }

    }
}

2 Answers

Mike Wagner
Mike Wagner
23,559 Points
Mike Wagner
Mike Wagner
23,559 Points

I'm not sure, but is there other code that controls the fly movement? If not, then the issue here is that you are not re-assigning the transform of the fly to equal the updated flyPosition value.

As for the destroying of flies, I can't remember if the fly itself or the frog was responsible for this action. If the flies are intended to handle their own destruction, then you have no code showing here that supports that functionality. You would need an OnTriggerEnter() call similar to this

void OnTriggerEnter(Collider other) {
        Destroy(other.gameObject);
}

from the Unity Docs. You will need to check the collider of the object it collides with to see if it is the Player, and instead of destroying the player, you would destroy the fly, but I'll give you a chance to figure it out. I'll help more if you still need it.

Joel Price
Joel Price
13,711 Points
Joel Price
Joel Price
13,711 Points

yeah, the code for FlyMovement 

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class FlyMovement : MonoBehaviour {

    [SerializeField]
    private Transform center;
    private float flySpeed;


    // Use this for initialization
    void Start () {

        flySpeed = Random.Range (300f, 700f);

    }

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

        transform.RotateAround (center.position, Vector3.up,  flySpeed * Time.deltaTime);

    }
}

but it was working before I added the code I linked in my post.

Mike Wagner
Mike Wagner
23,559 Points

Joel Price - There's nothing wrong with your code that I can see. I didn't copy it into my own version of this project, but it appears to be identical after a couple read-throughs and mine still functions as expected. Did you remember to assign the flyPrefab in the inspector? Is the FlySpawner script attached to the GameManager? Is the GameManager in the scene?

Joel Price
Joel Price
13,711 Points
Joel Price
Joel Price
13,711 Points

mwagner - I'm pretty sure I've got all of those things set up, however after stepping away from it for a bit and coming back to it, now for whatever reason, the original fly I had before writing the FlySpawner script is working perfectly, but the spawned flies still have no collision reaction or flying around animation.

Mike Wagner
Mike Wagner
23,559 Points

I would make sure that there aren't any of the original fly in the scene, then put one of the prefab flies into the scene, making sure it has all the scripts it needs on it. Then I would make sure that the prefab is assigned to the game manager, making sure to apply any changes as necessary. It sounds like you might have assigned the original fly to the game manager instead of the prefab, or like you added the script to the original fly (or possibly to one of the in scene prefabs without applying the changes across all prefabs). i can't exactly see your project but that's my guess.