Runtime Collectables

Written by: Akram Taghavi-Burris | © Copyright 2024

Building on the systems we've established for loading and saving collectable data within the editor, we will now implement a runtime collectable spawner that dynamically generates collectables based on the data loaded from our CSV file. Additionally, we will cover how to save changes to collectable data at runtime, ensuring that your game remains flexible and data-driven. By the end of this chapter, you will have a comprehensive understanding of how to manage collectables effectively while your game is running.

Load CSV Data at Runtime

To facilitate the dynamic generation of collectables during gameplay, we will first focus on loading collectable data from our CSV file at runtime. This process involves creating a system that not only retrieves the data but also prepares it for use in the game environment. By leveraging the CollectableLoader, we can easily pull in the collectable data that we have defined in our CSV file. This will serve as the foundation for our next step, where we will create a collectable spawner that utilizes this data to instantiate collectable objects in the scene.

Collectable Spawner

To begin, we'll create a simple collectable spawner that utilizes the CollectableLoader to load data at runtime. This spawner will instantiate collectable objects based on the information stored in the CSV file. The spawner will need:

• Collectable Prefab: A reference to the collectable prefab that will be instantiated in the scene.
• Collectable Loader: a reference to the CollectableLoader component, which is responsible for loading the collectable data from the CSV file.
• Start Method: On the Start method the class will load the data from the CollectableLoader reference. For each CollectableData loaded, the data will be assigned to the collectable prefab game object and then instantiated at the spawner's position.

The following code illustrates how to create the CollectableSpawner:

CollectableSpawner.cs

using System.Collections.Generic;
using UnityEngine;

public class CollectableSpawner : MonoBehaviour
{
    [SerializeField]
     private CollectableLoader _collectableLoader; // Reference to the CollectableLoader

     [SerializeField]
     private GameObject _collectablePrefab; // Reference to the collectable prefab

     private Vector3 _pos; //position of spawner
     private float _offsetDistance = 2f; //an offset distance to avoid the objects instating on top of each other

     // Start is called before the first frame update
     void Start()
     {
         _pos = transform.position; // Get the initial position of the spawner

         List<CollectableData> collectables = LoadCollectables(); // Load collectable data

         //for each collectable in the list
         foreach (CollectableData data in collectables)
         {
             SpawnCollectable(data); // Spawn and set up the collectable

         }//end foreach (CollectableData data in collectables)

     }//end Start()

     //Load the collectables from the CollectableLoader and return the list
     private List<CollectableData> LoadCollectables()
     {
         return _collectableLoader.LoadCollectables(); // Load and return collectable data
     }//end LoadCollectables()

     //SpwanCollectable
     void SpawnCollectable(CollectableData data)
     {
       Vector3 spawnPosition = CalculateSpawnPosition(); //calculate the spawn position by offesting the x

        // Instantiate the collectable GameObject at the spawner's position
        GameObject collectable = Instantiate(_collectablePrefab, spawnPosition, Quaternion.identity);

         SetupCollectable(collectable, data); // Set up the collectable with the loaded data

     }//end SpawnCollectable

    // Calculates the spawn position by updating the x-offset distance and returning the new position
    private Vector3 CalculateSpawnPosition()
    {
        _offsetDistance++; // Increase the offset distance

        // Return the new position, offsetting the x coordinate by _offsetDistance
        return new Vector3(_pos.x + _offsetDistance, _pos.y, _pos.z);
    }//end CalculateSpawnPosition()

    //Setup the collectable for use in the game
    void SetupCollectable(GameObject collectable, CollectableData data)
     {
         collectable.name = data.CollectableName; // Set the name of the instantiated GameObject

         // Get the Collectable component from the instantiated GameObject
         Collectable collectableComponent = collectable.GetComponent<Collectable>();

         // Assign the loaded data to the collectable component
         collectableComponent.CollectableData = data;
     }//end SetupCollectable()

}

Setting Up the Spawner

Now that we have our CollectableSpaner class we need to set it up in the scene to spawn collectables at runtime. To do this we will need to:

1. Create an empty GameObject in the scene and name it "CollectableSpawner"
2. Attach the CollectableSpawner component (script) to this GameObject.
3. Assign the collectable prefab to the collectablePrefab field in the Inspector.
4. Press Play to see the objects created from the csv file into the game.

Save Data to CSV at Runtime

Next, we will implement the functionality to save changes made to collectable data during runtime back to the CSV file. This can be particularly useful for game design scenarios where you may want to modify collectable attributes based on player actions or other game mechanics.

CollectableCreator

We introduce the CollectableCreator class, which is responsible for dynamically creating new collectables during runtime and saving them to a CSV file. This functionality allows for real-time modifications to collectable attributes based on player actions or other game events. Let's break down the components of the class:

• Public Fields: We will need a reference to the CollectableSpawner, which handles spawning collectables in the game world. It also requires a reference to the CollectablePrefab, which will be used to visually represent the collectable in the scene. Lastly, the class uses CollectableName, PointValue, and CollectedSound to define the attributes of each new collectable, including its name, point value, and the sound played when collected.

• OnTriggerEnter() Method: We need a method that will trigger the creation of the new collectable. For now a simple OnTriggerEnter will work. When an object enters the CollectableCreator object trigger zone. it will initiates the creation of a new collectable. When triggered, it calls the CreateNewCollectable() method, passing the values of CollectableName, PointValue, and CollectedSound to define the properties of the new collectable.

• CreateNewCollectable() Method: This is the core function of the CollectableCreator class. When invoked, it performs the following steps:

1. Creates a New Collectable Data Object: A new instance of CollectableData is created using ScriptableObject.CreateInstance. This object will hold the data for the new collectable, including its name, point value, and sound effect.
2. Sets Collectable Properties: The CollectableData object's fields are populated with the values provided (name, point value, sound).
3. Saves the Data: The CollectableSaver.SaveCollectableData() method is then called to save the newly created collectable's data to a CSV file. This step ensures that changes to collectable attributes are stored persistently.
4. Spawns the Collectable: If a CollectableSpawner is linked, the CollectableSpawner.SpawnNewCollectable() method is called to place the new collectable in the game world.
5. Logging: A debug log is generated to confirm that a new collectable has been successfully created, making it easier to track the process during development.

CollectableCreator.cs

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

public class CollectableCreator : MonoBehaviour
{
    public CollectableSpawner CollectableSpawner; // Reference to the CollectableSpawner
    public GameObject CollectablePrefab; // Reference to the collectable prefab
    public string CollectableName; //name for new collectable
    public int PointValue; //new collectable point value
    public AudioClip CollectedSound; //Sound clip for new collectable

    //When triggered create new collectable
    private void OnTriggerEnter(Collider other)
    {
        CreateNewCollectable(CollectableName, PointValue, CollectedSound);
    }//end OnTriggerEnter()

    //Creates a new collectable 
    public void CreateNewCollectable(string collectableName, int pointValue, AudioClip collectedSound)
    {
        // Create a new CollectableData instance
        CollectableData newCollectableData = ScriptableObject.CreateInstance<CollectableData>();

        // Set the properties for the new collectable
        newCollectableData.CollectableName = collectableName;
        newCollectableData.PointValue = pointValue;
        newCollectableData.CollectedSound = collectedSound;

        // Save the new collectable data to the CSV file
        CollectableSaver.SaveCollectableData(newCollectableData);

        // if there is a spawner the new collectable in the game world
        if (CollectableSpawner != null) { CollectableSpawner.SpawnNewCollectable(newCollectableData); }

        // Debg.Log the name of the newly created collectable
        Debug.Log($"New collectable created: {collectableName}");

    }//end CreateNewCollectable()
}

Spwan new Collectable

To save the new collectable we need to update the Collectable spawner to spawn the new collectable

CollectableSpawner.cs

using System.Collections.Generic;
using UnityEngine;

public class CollectableSpawner : MonoBehaviour
{
    [SerializeField]
     private CollectableLoader _collectableLoader; // Reference to the CollectableLoader

     [SerializeField]
     private GameObject _collectablePrefab; // Reference to the collectable prefab

     private Vector3 _pos; //position of spawner
     private float _offsetDistance = 2f; //an offset distance to avoid the objects instating on top of each other

     // Start is called before the first frame update
     void Start()
     {
         _pos = transform.position; // Get the initial position of the spawner

         List<CollectableData> collectables = LoadCollectables(); // Load collectable data

         //for each collectable in the list
         foreach (CollectableData data in collectables)
         {
             SpawnCollectable(data); // Spawn and set up the collectable

         }//end foreach (CollectableData data in collectables)

     }//end Start()

     //Load the collectables from the CollectableLoader and return the list
     private List<CollectableData> LoadCollectables()
     {
         return _collectableLoader.LoadCollectables(); // Load and return collectable data
     }//end LoadCollectables()

     //SpwanCollectable
     void SpawnCollectable(CollectableData data)
     {
       Vector3 spawnPosition = CalculateSpawnPosition(); //calculate the spawn position by offesting the x

        // Instantiate the collectable GameObject at the spawner's position
        GameObject collectable = Instantiate(_collectablePrefab, spawnPosition, Quaternion.identity);

         SetupCollectable(collectable, data); // Set up the collectable with the loaded data

     }//end SpawnCollectable

    // Calculates the spawn position by updating the x-offset distance and returning the new position
    private Vector3 CalculateSpawnPosition()
    {
        _offsetDistance++; // Increase the offset distance

        // Return the new position, offsetting the x coordinate by _offsetDistance
        return new Vector3(_pos.x + _offsetDistance, _pos.y, _pos.z);
    }//end CalculateSpawnPosition()

    //Setup the collectable for use in the game
    void SetupCollectable(GameObject collectable, CollectableData data)
     {
         collectable.name = data.CollectableName; // Set the name of the instantiated GameObject

         // Get the Collectable component from the instantiated GameObject
         Collectable collectableComponent = collectable.GetComponent<Collectable>();

         // Assign the loaded data to the collectable component
         collectableComponent.CollectableData = data;
     }//end SetupCollectable()

    // Spawn a new collectable at runtime
    public void SpawnNewCollectable(CollectableData newCollectableData)
    {
        SpawnCollectable(newCollectableData); // Use the existing method to spawn the new collectable
    }//end SpawnNewCollectable()


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