Roll a ball simply will not move

Questions & Answers
1

I’m trying to move the ball with the player controller script, at the Environment and Player tutorial with the code exactly as written, but with an extra snippet to see if the script is getting the rigidbody component, and VS shows no errors. When I start the game, the ball will not move with either the arrow keys or wasd, and at the line that adds force to the rigidbody, rb.AddForce (movement * speed); , I keep getting an error that says NullReferenceException: Object reference not set to an instance of an object. I’ve seen this question asked many times, but never answered. Here is the code I’m using, and there’s no typos.

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

public class PlayerController : MonoBehaviour
{
private Rigidbody rb;

public float speed = 10.0f;

void Start()
{
    rb = GetComponent<Rigidbody>();
}
void FixedUpdate()
{
    float moveHorizontal = Input.GetAxis("Horizontal");

    float moveVertical = Input.GetAxis("Vertical");

    Vector3 movement = new Vector3(moveHorizontal, 0.0f, moveVertical);

    rb.AddForce (movement * speed);

    if (rb = null)
    {
        Debug.Log("There is no rigidbody in " + transform.name);
    }
    else
        Debug.Log("Rigidbody component from gameobject is aquired.");
}

}

3

well… on the line 16 you have :

 if (rb = null)

This is seting your rigidbody to null instead of compare it’s value, you need to use the “==” operator.

The line 15 it’s just fine, but only runs the first time, the second time the rb property is null (that’s why you are getting the NullReferenceException)

2

what line is it on?
if u can say what line it’s on I can help

4

I actually tried commenting out that if/else statement and now it suddenly works. Thank you all for helping me out. :smiley: