ScreenToWorldPoint giving NullReferenceException

I am testing a simple 2D game player controller script. I am using ScreenToWorldPoint to have the player follow the mouse location. The code looks ok and the values for x,y, and z are showing up ok. But when the script gets to invoking the ScreenToWorldPoint call for the Camera I get a NullReferenceException.

Code (CSharp):

1. using System.Collections;
2. using UnityEngine;
3. public class PlayerController : MonoBehaviour {
4.     private Rigidbody ThisBody = null;
5.     private Transform ThisTransform = null;
6.     public bool MouseLook = true;
7.     public string HorzAxis = "Horizontal";
8.     public string VertAxis = "Vertical";
9.     public string FireAxis = "Fire1";
10.     public float MaxSpeed = 5f;
11.     // Use this for initialization
12.     void Awake () {
13.         ThisBody = GetComponent<Rigidbody>();
14.         ThisTransform = GetComponent<Transform>();
15.     }
16.     //
17.     void FixedUpdate () {
18.         // Get axis input values
19.         float Horz = Input.GetAxis(HorzAxis);
20.         float Vert = Input.GetAxis(VertAxis);
21.         // set direction to move
22.         Vector3 MoveDirection = new Vector3(Horz, 0.0f, Vert);
23.      
24.         //Clamp speed of player's ship
25.         ThisBody.AddForce(MoveDirection.normalized * MaxSpeed);
26.         ThisBody.velocity = new Vector3(
27.             Mathf.Clamp(ThisBody.velocity.x, -MaxSpeed, MaxSpeed),
28.             Mathf.Clamp(ThisBody.velocity.y, -MaxSpeed, MaxSpeed),
29.             Mathf.Clamp(ThisBody.velocity.z, -MaxSpeed, MaxSpeed));
30.         if (MouseLook)
31.         {
32.             Debug.Log("In Mouselook: position x is: " + Input.mousePosition.x + " position y is: " + Input.mousePosition.y + " position z is: " + +Input.mousePosition.z);
33.             var x = Input.mousePosition.x;
34.             var y = Input.mousePosition.y;
35.             var z = Input.mousePosition.z;
36.             Vector3 screenPosition = new Vector3(x,y,z);
37.             Debug.Log("screenPosition is: " + screenPosition + " Location: " + Camera.main.ScreenToWorldPoint(position: screenPosition));
38.             Vector3 MousePos = Camera.main.ScreenToWorldPoint(position: screenPosition);
39.              MousePos = new Vector3(screenPosition.x, 0.0f, screenPosition.z);
40.             Debug.Log("MousePosWorld: " + MousePos);
41.             Vector3 LookDirection = MousePos - ThisTransform.position;
42.             //rotation
43.             ThisTransform.localRotation = Quaternion.LookRotation(LookDirection.normalized, Vector3.up);
44.         }
45.     }
46. }

 

So the NullReferenceException occurs on line 38 in the above code snippet? Do you have a main camera in your scene? To use `Camera.main` you should have a camera in the scene with the MainCamera tag set on it. Do you have such a camera in your scene?

Sam

 

Camera was not tagged, DUH!