Character Controller is NULL when referenced

[CoyYonce]

Hello all.

This is my first attempt at scripting movement of an object in Unity. I’m working through the tutorials here: http://www.youtube.com/watch?v=rhpJPx8fICQ which seems to be a nice introduction to movement of objects.

I have an object that I’ve imported from blender. It is a bee and is a combination of multiple objects (i.e., a body, two eyes, and wings). I’ve added a Character Controller to the parent object named “bee”. I’ve also created a FirstPersonController script in C# following the aforementioned tutorial. I’ve added the FirstPersonController script to my “bee” object as well.

My reference to the CharacterController is returned as NULL as discovered by the following code:

void Update () {
CharacterController controller = GetComponent();

if (controller == null) {
Debug.Log(“The controller is null!”);
}

I have two questions:

1. How can I determine why the Character Controller cannot be found even when it is attached the same object as the script?
2. Why does the bee object still allow me to move it forward and sideways (via the code below) even though the controller is NULL?

// Movement
float verticalSpeed = Input.GetAxis(“Vertical”) * speed;
float horizontalSpeed = Input.GetAxis(“Horizontal”) * speed;
Vector3 forward = new Vector3(horizontalSpeed, 0, verticalSpeed);
//if(controller != null) {
controller.SimpleMove(forward);
//}

Thank you for any help that you can provide.

Coy

[CoyYonce]

Seems like it has something to do with the fact that I have multiple objects combined into a single parent object. I generated a simple cube in blender and a simple corridor. I put them into Unity and almost everything is working perfectly. Any pointers to figuring out how to appropriately apply a character controller and movement script to an object that is made up of multiple child objects?

[CoyYonce]

The combined object using multiple objects to form the bee was causing problems with the movement. I’ll be doing some searching to figure out how to get this work; however, I was able to get a simple cube moving.

I used the following as references:

How would you do a constant moving a character controller?

Unity 3d: Simple First-Person Shooter Tutorial - Part 2

My final script looks like this:

using UnityEngine;
using System.Collections;

public class FPSController : MonoBehaviour {

// Variables for defining modifier to vertical, horizontal, and rotational movement
public float movementSpeed = 5.0F;
public float mouseSensitivity = 3.0F;

// Constant for defining continual vertical movement
const float constantMotion = 3.0F;

// Setup CharacterController
private CharacterController controller;

// Use this for initialization
void Start () {

// Initialize CharacterController
controller = GetComponent();
}

// Update is called once per frame
void Update () {

// Control Rotation per Frame
float rotLeftRight = Input.GetAxis(“Mouse X”);
transform.Rotate(0, rotLeftRight * mouseSensitivity, 0);

// Control Horizontal Movement per Frame. Vertical Movement is constant.
//float forwardSpeed = Input.GetAxis (“Vertical”) * movementSpeed;
float sideSpeed = Input.GetAxis (“Horizontal”) * movementSpeed;
Vector3 speed = new Vector3 (sideSpeed, 0, constantMotion);
//speed = transform.rotation * speed;

// Execute Controller Movement
controller.SimpleMove(speed);
}
}

[lorenalexm]

Have you tried creating an empty game object, and placing your bee mesh as the child of said object. From there you can simply place your components on the top level game object and it should take care of the issue.

[CoyYonce]

Thanks for the reply.

This did, indeed, work. Will this cause any problems with referencing the bee object in the code later or with maintenance? I can’t forsee any reason that it would; however, I’m fairly new to building games using Unity.

[lorenalexm]

If you’re needing to reference the actual mesh of the bee within one of the scripts on the top level object, I might suggest exposing a field to the inspector and handling the reference there. This way if the mesh changes further into development, you can just change the inspector field and be done with it, nothing in the script should need to be changed.