Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Game Development How to Make a Video Game Score, Enemies, and Game State Add a Start and End

player Randomly dies and error message appears.

After adding the Start and End My player randomly dies and doesn't respawn. Also get an error saying "missing reference Exception". I don't understand how this happened, I reviewed the videos to make sure my codes were incomplete some where, however there was no errors.

1 Answer

Tyler Corum
Tyler Corum
3,514 Points

Don't give up! I recommend to work at a problem for 15-20 minutes max. If you cannot solve the issue, you need to provide relevant information, such as... when does the player die (hint: it's not random). Is it after you press spacebar, is it while you're moving, are you anywhere close to the bird, is it after 3 or 5 seconds (i.e. is it consistent)?. The code isn't written to respawn the player except for when the proper exit is taken when playerHealth.alive == false (a single = sign sets values; a double == sign operator compares values, check this). Double check your PlayerHealth class file too. Here is my working GameState.cs file and PlayerHealth.cs file. You'll have to check the connections in the Game Manager Game State (script) in the Inspector in Unity, too:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.SceneManagement;

public class GameState : MonoBehaviour {

    private bool gameStarted = false;

    [SerializeField]
    private Text gameStateText;
    [SerializeField]
    private GameObject player;
    [SerializeField]
    private BirdMovement birdMovement;
    [SerializeField]
    private FollowCamera followCamera;
    private float restartDelay = 3f;
    private float restartTimer;
    private PlayerMovement playerMovement;
    private PlayerHealth playerHealth;


    // Use this for initialization
    void Start () {
        Cursor.visible = false;

        playerMovement = player.GetComponent<PlayerMovement>();
        playerHealth = player.GetComponent<PlayerHealth>();

        // Prevent the player from moving at the start of the game
        playerMovement.enabled = false;

        // Prevent bird from moving at start of game
        birdMovement.enabled = false;

        // Prevent the follow camera from moving to the game position
        followCamera.enabled = false;
    }

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

        // If the game is not started and the player presses the spacebar...
        if (gameStarted == false && Input.GetKeyUp (KeyCode.Space))
        {
            // ...start the game.
            StartGame();
        }

        // If the player is no longer alive...
        if (playerHealth.alive == false)
        {
            // ...end the game...
            EndGame();

            // ...incrememt a timer to count up to restarting...
            restartTimer = restartTimer + Time.deltaTime;

            // ...and if it reaches the restart delay...
            if (restartTimer >= restartDelay)
            {
                // ...then reload the currently loaded scene
                SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
            }
        }
    }

    private void StartGame()
    {
        // Set the game state
        gameStarted = true;

        // Remove the start text
        gameStateText.color = Color.clear;

        // Allow the player to move
        playerMovement.enabled = true;

        // Allow the bird to move
        birdMovement.enabled = true;

        // Allow the camera to move
        followCamera.enabled = true;
    }

    private void EndGame()
    {
        // Set the game state
        gameStarted = false;

        // Show the game over text
        gameStateText.color = Color.white;
        gameStateText.text = "Game Over!";

        // Remove the player from the game
        player.SetActive(false);
    }
}
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerHealth : MonoBehaviour
{

    public bool alive;
    [SerializeField]
    private GameObject pickupPrefab;


    // Use this for initialization
    void Start()
    {
        alive = true;
    }

    void OnTriggerEnter(Collider other)
    {
        // ...If the collider other is tagged with player...
        // ...aka if the bird runs into the player...
        if (other.CompareTag("Enemy") && alive == true)
        {
            alive = false;

            // Create the pickup particles
            Instantiate(pickupPrefab, transform.position, Quaternion.identity);

            //// ...decrease total number of flies...
            //FlySpawner.totalFlies = 0;

            //// ...update the score...
            //ScoreCounter.score = 0;

            //Destroy(gameObject);
        }
    }
}

Keep in mind in my PlayerHealth class I was messing around with the code before I watched the video in how I would reset things. It is commented out, but I'm leaving it in my codeblock .