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Game Development Object-Oriented Programming in Unity Interfaces Implementing Interfaces

Justin Molyneaux
Justin Molyneaux
13,329 Points
Posted by Justin Molyneaux
Justin Molyneaux
13,329 Points

ERROR - My Arrows Bounce Off of the Targets

For some reason, after I implemented the ITargetable Interface when I shoot my arrows they just bounce off of the targets.

The arrows are supposed to hit the targets and then stay stuck in them.

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

Did you inherit from IReboundable? :stuck_out_tongue_winking_eye: Just kidding.

But it might help to share your code!

Justin Molyneaux
Justin Molyneaux
13,329 Points
Justin Molyneaux
Justin Molyneaux
13,329 Points

Hahaha, no IReboundable utilized yet.

Here is my code that I attached as a Component to the Arrow prefab.

using UnityEngine;
using System.Collections;

public class ArrowCollision : MonoBehaviour 
{
    private void onCollisionEnter(Collision other)
    {
        if (other.gameObject.GetComponent<ITargetable> () != null) 
        {
            // checks to see if OnCollisionEnter() is being called when arrow hits target
            Debug.Log("Arrow hit the target");

            // Call the TargetReaction() on the component that implements the ITargetable interface

            other.gameObject.GetComponent<ITargetable>().TargetReaction ();

            // Stop the arrow from moving.
            GetComponent<Rigidbody>().isKinematic = true;

            // Parent the arrow to the target so that it's "stuck" to the target.
            gameObject.transform.parent = other.transform;

        }
    }
}
Justin Molyneaux
Justin Molyneaux
13,329 Points
Justin Molyneaux
Justin Molyneaux
13,329 Points

Here is my ITargetable Interface

using UnityEngine;
using System.Collections;

public interface ITargetable 
{
    void TargetReaction ();
}
Justin Molyneaux
Justin Molyneaux
13,329 Points
Justin Molyneaux
Justin Molyneaux
13,329 Points

Here is where I implemented the interface in the Target.cs

using UnityEngine;
using System.Collections;

public class Target : MonoBehaviour, ITargetable {

    [SerializeField]
    protected GameObject impactParticles;

    protected AudioSource impactSounds;


    protected virtual void Start() {

        impactSounds = GetComponent<AudioSource>();

    }


    public virtual void DestroyTarget()
    {
        // Enable the rigidbody on the target to allow it to fall.
        GetComponent<Rigidbody>().isKinematic = false;

        // Turn off collisions to prevent double hits.
        GetComponent<Collider>().enabled = false;

        // Start to destroy this object.
        Destroy(gameObject, 1f);
    }

    public virtual void TargetReaction()
    {

        // tests to see if this method is being called
        Debug.Log("TargetReaction is being called.");

        // Play an impact sound.
        impactSounds.Play();

        // Spawn hit particles.
        Instantiate(impactParticles, transform.position, Quaternion.identity);

        // Decrement the total number of targets.
        TargetSpawner.totalTargets--;

        // Add the target to the score.
        GameManager.score++;

        // Destroy the target.
        DestroyTarget ();
    }

}

1 Answer

Justin Molyneaux
Justin Molyneaux
13,329 Points
Justin Molyneaux
Justin Molyneaux
13,329 Points

I figured it out. It's because I wrote "onCollisionEnter" instead of the correct "OnCollisionEnter" method. Now my game works as expected.