Weid Null reference exception

Target Platforms Mobile
1

Hi there,

I am using this script from Peneolpe tutorial to get additionnal life when the player collide with the game object it is attached to :

ParticlePickup.js

var emitter : ParticleEmitter;
var index : int;
var collectedParticle : GameObject;
private var sk : ChronoScoreKeeperKBNew00;
// OnTriggerEnter is called whenever a Collider hits this GameObject's collider
function OnTriggerEnter(other : Collider)
{
	sk = other.GetComponent( ChronoScoreKeeperKBNew00 );
	sk.Pickup( this );
}


// Collected is called when the player picks up this item.
function Collected()
{
	// Spawn particles where the orb was collected
	Instantiate( collectedParticle, transform.position, Quaternion.identity );
	
	// Scale the particle down, so it is no longer visible
 	var particles : Particle[] = emitter.particles;	 	
 	particles[ index ].size = 0;	 	
 	emitter.particles = particles;
	
	// Destroy the collider for this orb
	Destroy( gameObject );
}

and I have this Function Pickup within a script (ChronoScoreKeeperKBNew00) attached to the player :

public function Pickup( pickup : ParticlePickup )
{
	if ( playerInfo.health < playerInfo.maxHealth )
	{
	 	playerInfo.health++;
	 	UpdateHealthGui();
	 			
	 	pickup.Collected();	
		PlayAudioClip( pickupSound, pickup.transform.position, 1.0 );
	}
	else
	{
		var warning : GameObject = Instantiate( guiMessage );
		warning.guiText.text = "You already have a six pack life";
		Destroy(warning, 2);
	}
		
}

What puzzles me is that everything works fine, I get the additionnal life when my player collides with this GO, I get the sound, I get the txt message if I already have the maxHealth, but I get a" null reference exception : Object reference not set to an instance of an object" which points to ParticlePickup script on the following line :

sk.Pickup( this );

Am I missing something here ??
thks in advance for your help .

2

If you’ve got something like this:-

sk = other.GetComponent( ChronoScoreKeeperKBNew00 );
sk.Pickup( this );

…and there is a null reference reported on the second line, it probably means the result returned by the GetComponent call was null. You can check for sure by adding an explicit test:-

if (sk == null) {
    print("sk is null");
}

If it turns out that sk is null, then the first thing to check is that there actually is a ChronoScoreKeeperKBNew00 script attached to the “other” collider object. It’s likely that the object is colliding with something unexpected.

3

Thanks Andeee, you helped me again find the problem. There was obviously another object colliding so I am now more specific with this code and everything’s fine.

function OnTriggerEnter(other : Collider)
{
	if(other.collider.tag == "Player"){			
	sk = other.GetComponent( ChronoScoreKeeperKBNew00 );
	sk.Pickup( this );
	}	

}