NullReferenceException: Object reference not set to an instance of an object (With animation)

Unity Engine
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1

Hello, I am new to unity and am trying to connect the animator’s parameters to the player script. But this error keeps popping up:

NullReferenceException: Object reference not set to an instance of an object
PlayerControls.Update () (at Assets/Scripts/PlayerController.cs:21)

The code was doing good before and all I did was copy some code from the unity manual (Unity - Manual: Animation Parameters) to try to get it to work.

I really don’t know what to do since it’s code that works added onto more code that works, but the result doesn’t work?!

Here is my code:

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

public class PlayerControls : MonoBehaviour
{
    Animator animator;
 
    // Initialization
    void Start ()
    {
        animator = GetComponent<Animator>();
    }
    public Vector2 speed = new Vector2(50, 50);

    // Update is called once per frame
    void Update()
    {
        float inputX = Input.GetAxis("Horizontal");
        float inputY = Input.GetAxis("Vertical");

        animator.SetFloat("moveX",inputX);
        animator.SetFloat("moveY",inputY);

        Vector3 movement = new Vector3(speed.x * inputX, speed.y * inputY, 0);

        movement *= Time.deltaTime;

        transform.Translate(movement);
    }
}

If I’m stupid and there’s a way easier way to do this let me know.

2

If I were to guess I would say animator is null.
Do you have an Animator component on the same GameObject as the script?

Try adding a check after GetComponent to make sure its not null.

3

Yes, I do have an animator component on Player:
Do you see anything else wrong?

9388826--1313468--image_2023-10-04_085947889.png

4

This forum is for the Job System, not generic C# scripting. I’ll move your post for you.

5

The answer is always the same… ALWAYS!

How to fix a NullReferenceException error

https://forum.unity.com/threads/how-to-fix-a-nullreferenceexception-error.1230297/

Three steps to success:

  • Identify what is null ← any other action taken before this step is WASTED TIME
  • Identify why it is null
  • Fix that
6

This literally describes EVERY step of every day for computer software engineering.

There is nothing else except breaking stuff and fixing it better. That’s how it works.

It really is always the same: Take functioning stuff and BREAK IT, and then try to figure out and fix why it’s broken.

If you don’t like that, get out now.

If you want to thrive in this exciting world of software engineering, then step up your game!!!

Time to start debugging! Here is how you can begin your exciting new debugging adventures:

You must find a way to get the information you need in order to reason about what the problem is.

Once you understand what the problem is, you may begin to reason about a solution to the problem.

What is often happening in these cases is one of the following:

  • the code you think is executing is not actually executing at all
  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is
  • you’re getting an error or warning and you haven’t noticed it in the console window

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the names of the GameObjects or Components involved?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as Debug.Log("Problem!",this);

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

Visit Google for how to see console output from builds. If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer for iOS: https://discussions.unity.com/t/700551 or this answer for Android: https://discussions.unity.com/t/699654

If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

If your problem is with OnCollision-type functions, print the name of what is passed in!

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

https://discussions.unity.com/t/839300/3

“When in doubt, print it out!™” - Kurt Dekker (and many others)

Note: the print() function is an alias for Debug.Log() provided by the MonoBehaviour class.

7

You seem to enjoy talking down on people for some reason. I don’t think a game engine forum is really the place for that. Please be respectful and cordial to others when you post. There’s no reason to patronize someone with less experience than you and tell them to get out of game development.

8

I understand. I know what “null” is and I know that the program is taking in “null” when it should not. I’m just looking for extra help because I couldn’t find the error.

I’ve figured out the problem, it’s because the () after void start is one space off, so it is “void start ()” when it should be “void start()”

Thank you for your help!

9

The space between the brackets on a method makes no difference, that won’t be your problem. Did your original start method have a lowercase s, and you then changed it to an uppercase S? That’s a common mistake that catches people out.

10

Yes, spaces and new lines don’t matter in C#… you can write this and it’s still correct:

public














void


Start                                        ()