Please help me - NullReferenceException

Unity Engine
1

I’ve folowed a video tutorial on youtube on how to make a simple day / night cycle, but it seems that nomatter what i try i’ll always get these errors, can anyone help me fixing this please?

NullReferenceException: Object reference not set to an instance of an object
DayNight.Update () (at Assets/DayNightyCycle/DayNight.js:10)

NullReferenceException: Object reference not set to an instance of an object
DayNight.Update () (at Assets/DayNightyCycle/DayNight.js:14)

var theSun : GameObject;
var cam : GameObject;
var day : Material;
var night : Material;

function Update () 
{
	if (theSun.light.enabled == true) 
	{
		cam.GetComponent(Skybox).material = day;
	}
	else 
	{
		cam.GetComponent(Skybox).material = night;
	}
}

I have everything assigned in the inspector, which i would think was the problem :confused:

2

Yea i had a similar problem with get component. It kept giving me a null ref exception.
I would do something like this:

var theSun : GameObject;
var cam : GameObject;
var day : Material;
var night : Material;
var mySkybox : Skybox;

function Start()
{
     if(cam != null)
     {
          mySkybox = cam.GetComponent<Skybox>(); //If you can use this implementation in javascript
     }
}

function Update () 
{
    if (theSun.light.enabled == true) 
    {
        mySkybox.material = day;
    }
    else 
    {
       mySkybox.material =  night;
    }
}
3

Thanks for your response, it didn’t work though :confused:

4

your cam object probably doesnt have the skybox component.
Try this

var theSun : GameObject;

var cam : GameObject;

var day : Material;

var night : Material;

 
function Start () {

        if ( cam.GetComponent(Skybox) == null )
              Debug.Log("the cam has no skybox component at all!");

        if ( cam.GetComponent(Skybox).material == null )
              Debug.Log("the skybox has no material at all!");
}

function Update () 

{

    if (theSun.light.enabled == true) 

    {

         cam.GetComponent(Skybox).material = day;

    }

    else 

    {

        cam.GetComponent(Skybox).material = night;

    }

}

And watch the console output, then report back what was logged.

5

Thanks for your reply. This is what was logged in the console

the cam has no skybox component at all!
UnityEngine.Debug:Log(Object)
DayNight:Start() (at Assets/DayNightyCycle/DayNight.js:10)

NullReferenceException: Object reference not set to an instance of an object
DayNight.Start () (at Assets/DayNightyCycle/DayNight.js:12)

NullReferenceException: Object reference not set to an instance of an object
DayNight.Update () (at Assets/DayNightyCycle/DayNight.js:20)

What i get from this is, that there’s no skybox attached? If this is correct, then how do i create a skybox file?

6

that means your cam has no skybox component added. Check the tutorial you have been following again (try to take a look at the inspector of the cam object to see what the skybox component is. Maybe its just a normal skybox or a custom object made earlier in the tutorial) Camera’s dont have that by default so you must add it by yourself.

7

Yeah, going back and taking another look at the video did the trick :slight_smile: I found out he added a component to the camera without showing or mentioning anything about it, so that’s what i did wrong… So obvious lol :smile: Thanks for the help :slight_smile: