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Help with NullReferenceException
I am building off of the 2D Platformer tutorial and I have converted the sctrip for PlatformerController from javascript to C# but I'm am getting the following error at Runtime. The scipt is selected in the editor and when it runs with Javascript script it works fine. HJow can set the Object Reference to an object? Wouldn't assigning the script to the player in the editor assign it to the player and wouldn;t that be the object?
Error: NullReferenceException: Object reference not set to an instance of an object PlatformerController.Awake () (at Assets/Scripts/2D/Character Controls/PlatformerController.cs:125)
Note: Line 125 stis Line 11 below.
Thanks!
public PlatformerControllerJumping jump;
CharacterController controller;
// This is used to keep track of special effects in UpdateEffects ();
private bool areEmittersOn= false;
public void Awake (){
movement.direction = transform.TransformDirection (Vector3.forward);
controller = GetComponent<CharacterController>();
Spawn ();
}
public void Spawn (){
// reset the character's speed
movement.verticalSpeed = 0.0f;
movement.speed = 0.0f;
// reset the character's position to the spawnPoint
transform.position = spawnPoint.position;
}
Here is the entire script:
// Converted from UnityScript to C# at http://www.M2H.nl/files/js_to_c.php - by Mike Hergaarden
// Do test the code! You usually need to change a few small bits.
using UnityEngine;
using System.Collections;
public class PlatformerController : MonoBehaviour {
// Does this script currently respond to Input?
public bool canControl= true;
// The character will spawn at spawnPoint's position when needed. This could be changed via a script at runtime to implement, e.g. waypoints/savepoints.
public Transform spawnPoint;
void Start () {
}
public class PlatformerControllerMovement {
// The speed when walking
public float walkSpeed= 10.0f;
// when pressing "Fire1" button (control) we start running
public float runSpeed= 10.0f;
public float inAirControlAcceleration= 1.0f;
// The gravity for the character
public float gravity= 60.0f;
public float maxFallSpeed= 20.0f;
// How fast does the character change speeds? Higher is faster.
public float speedSmoothing= 5.0f;
// This controls how fast the graphics of the character "turn around" when the player turns around using the controls.
public float rotationSmoothing= 10.0f;
// The current move direction in x-y. This will always been (1,0,0) or (-1,0,0)
// The next line, @System.NonSerialized , tells Unity to not serialize the variable or show it in the inspector view. Very handy for organization!
//@System.NonSerialized
public Vector3 direction= Vector3.zero;
// The current vertical speed
//@System.NonSerialized
public float verticalSpeed= 0.0f;
// The current movement speed. This gets smoothed by speedSmoothing.
//@System.NonSerialized
public float speed= 0.0f;
// Is the user pressing the left or right movement keys?
//@System.NonSerialized
public bool isMoving= false;
// The last collision flags returned from controller.Move
//@System.NonSerialized
public CollisionFlags collisionFlags;
// We will keep track of an approximation of the character's current velocity, so that we return it from GetVelocity () for our camera to use for prediction.
//@System.NonSerialized
public Vector3 velocity;
// This keeps track of our current velocity while we're not grounded?
//@System.NonSerialized
public Vector3 inAirVelocity= Vector3.zero;
// This will keep track of how long we have we been in the air (not grounded)
//@System.NonSerialized
public float hangTime= 0.0f;
}
public PlatformerControllerMovement movement;
// We will contain all the jumping related variables in one helper class for clarity.
public class PlatformerControllerJumping {
// Can the character jump?
public bool enabled= true;
// How high do we jump when pressing jump and letting go immediately
public float height= 1.0f;
// We add extraHeight units (meters) on top when holding the button down longer while jumping
public float extraHeight= 4.1f;
// This prevents inordinarily too quick jumping
// The next line, @System.NonSerialized , tells Unity to not serialize the variable or show it in the inspector view. Very handy for organization!
//@System.NonSerialized
public float repeatTime= 0.05f;
//@System.NonSerialized
public float timeout= 0.15f;
// Are we jumping? (Initiated with jump button and not grounded yet)
//@System.NonSerialized
public bool jumping= false;
//@System.NonSerialized
public bool reachedApex= false;
// Last time the jump button was clicked down
//@System.NonSerialized
public float lastButtonTime= -10.0f;
// Last time we performed a jump
//@System.NonSerialized
public float lastTime= -1.0f;
// the height we jumped from (Used to determine for how long to apply extra jump power after jumping.)
//@System.NonSerialized
public float lastStartHeight= 0.0f;
}
public PlatformerControllerJumping jump;
CharacterController controller;
// Moving platform support.
private Transform activePlatform;
private Vector3 activeLocalPlatformPoint;
private Vector3 activeGlobalPlatformPoint;
private Vector3 lastPlatformVelocity;
// This is used to keep track of special effects in UpdateEffects ();
private bool areEmittersOn= false;
public void Awake (){
movement.direction = transform.TransformDirection (Vector3.forward);
controller = GetComponent<CharacterController>();
Spawn ();
}
public void Spawn (){
// reset the character's speed
movement.verticalSpeed = 0.0f;
movement.speed = 0.0f;
// reset the character's position to the spawnPoint
transform.position = spawnPoint.position;
}
void OnDeath (){
Spawn ();
}
public void UpdateSmoothedMovementDirection (){
float h= Input.GetAxisRaw ("Horizontal");
if (!canControl)
h = 0.0f;
movement.isMoving = Mathf.Abs (h) > 0.1f;
if (movement.isMoving)
movement.direction = new Vector3(h, 0, 0);
// Grounded controls
if (controller.isGrounded) {
// Smooth the speed based on the current target direction
float curSmooth= movement.speedSmoothing * Time.deltaTime;
// Choose target speed
float targetSpeed= Mathf.Min (Mathf.Abs(h), 1.0f);
//Pick speed modifier
if (Input.GetButton ("Fire2") && canControl)
targetSpeed *= movement.runSpeed;
else
targetSpeed *= movement.runSpeed;
movement.speed = Mathf.Lerp (movement.speed, targetSpeed, curSmooth);
movement.hangTime = 0.0f;
}
else {
// In air controls
movement.hangTime += Time.deltaTime;
if (movement.isMoving)
movement.inAirVelocity += new Vector3(Mathf.Sign(h), 0, 0) * Time.deltaTime * movement.inAirControlAcceleration;
}
}
void FixedUpdate (){
// Make sure we are absolutely always in the 2D plane. Doesn't do anything right now.
Vector3 temp = transform.position;
temp.z = 0;
//transform.position.z = temp;
}
public void ApplyJumping (){
// Prevent jumping too fast after each other
if (jump.lastTime + jump.repeatTime > Time.time)
return;
if (controller.isGrounded) {
// Jump
// - Only when pressing the button down
// - With a timeout so you can press the button slightly before landing
if (jump.enabled && Time.time < jump.lastButtonTime + jump.timeout) {
movement.verticalSpeed = CalculateJumpVerticalSpeed (jump.height);
movement.inAirVelocity = lastPlatformVelocity;
SendMessage ("DidJump", SendMessageOptions.DontRequireReceiver);
}
}
}
public void ApplyGravity (){
// Apply gravity
bool jumpButton= Input.GetButton ("Jump");
if (!canControl)
jumpButton = false;
// When we reach the apex of the jump we send out a message
if (jump.jumping && !jump.reachedApex && movement.verticalSpeed <= 0.0f) {
jump.reachedApex = true;
SendMessage ("DidJumpReachApex", SendMessageOptions.DontRequireReceiver);
}
// * When jumping up we don't apply gravity for some time when the user is holding the jump button
// This gives more control over jump height by pressing the button longer
bool extraPowerJump= jump.jumping && movement.verticalSpeed > 0.0f && jumpButton && transform.position.y < jump.lastStartHeight + jump.extraHeight && !IsTouchingCeiling ();
if (extraPowerJump)
return;
else if (controller.isGrounded)
movement.verticalSpeed = -movement.gravity * Time.deltaTime;
else
movement.verticalSpeed -= movement.gravity * Time.deltaTime;
// Make sure we don't fall any faster than maxFallSpeed. This gives our character a terminal velocity.
movement.verticalSpeed = Mathf.Max (movement.verticalSpeed, -movement.maxFallSpeed);
}
public float CalculateJumpVerticalSpeed ( float targetJumpHeight ){
// From the jump height and gravity we deduce the upwards speed
// for the character to reach at the apex.
return Mathf.Sqrt (2 * targetJumpHeight * movement.gravity);
}
void DidJump (){
jump.jumping = true;
jump.reachedApex = false;
jump.lastTime = Time.time;
jump.lastStartHeight = transform.position.y;
jump.lastButtonTime = -10;
}
//void UpdateEffects (){
// wereEmittersOn = areEmittersOn;
// areEmittersOn = jump.jumping && movement.verticalSpeed > 0.0f;
// By comparing the previous value of areEmittersOn to the new one, we will only update the particle emitters when needed
// if (wereEmittersOn != areEmittersOn) {
// for ( emitter in GetComponentsInChildren (ParticleEmitter)) {
// emitter.emit = areEmittersOn;
// }
// }
// }
void Update (){
if (Input.GetButtonDown ("Jump") && canControl) {
jump.lastButtonTime = Time.time;
}
UpdateSmoothedMovementDirection();
// Apply gravity
// - extra power jump modifies gravity
ApplyGravity ();
// Apply jumping logic
ApplyJumping ();
// Moving platform support
if (activePlatform != null) {
Vector3 newGlobalPlatformPoint= activePlatform.TransformPoint(activeLocalPlatformPoint);
Vector3 moveDistance= (newGlobalPlatformPoint - activeGlobalPlatformPoint);
transform.position = transform.position + moveDistance;
lastPlatformVelocity = (newGlobalPlatformPoint - activeGlobalPlatformPoint) / Time.deltaTime;
} else {
lastPlatformVelocity = Vector3.zero;
}
activePlatform = null;
// Save lastPosition for velocity calculation.
Vector3 lastPosition = transform.position;
// Calculate actual motion
Vector3 currentMovementOffset= movement.direction * movement.speed + new Vector3(0, movement.verticalSpeed, 0) + movement.inAirVelocity;
// We always want the movement to be framerate independent. Multiplying by Time.deltaTime does this.
currentMovementOffset *= Time.deltaTime;
// Move our character!
movement.collisionFlags = controller.Move (currentMovementOffset);
// Calculate the velocity based on the current and previous position.
// This means our velocity will only be the amount the character actually moved as a result of collisions.
movement.velocity = (transform.position - lastPosition) / Time.deltaTime;
// Moving platforms support
if (activePlatform != null) {
activeGlobalPlatformPoint = transform.position;
activeLocalPlatformPoint = activePlatform.InverseTransformPoint (transform.position);
}
// Set rotation to the move direction
if (movement.direction.sqrMagnitude > 0.01f)
transform.rotation = Quaternion.Slerp (transform.rotation, Quaternion.LookRotation (movement.direction), Time.deltaTime * movement.rotationSmoothing);
// We are in jump mode but just became grounded
if (controller.isGrounded) {
movement.inAirVelocity = Vector3.zero;
if (jump.jumping) {
jump.jumping = false;
SendMessage ("DidLand", SendMessageOptions.DontRequireReceiver);
Vector3 jumpMoveDirection= movement.direction * movement.speed + movement.inAirVelocity;
if (jumpMoveDirection.sqrMagnitude > 0.01f)
movement.direction = jumpMoveDirection.normalized;
}
}
// Update special effects like rocket pack particle effects
// UpdateEffects ();
}
void OnControllerColliderHit ( ControllerColliderHit hit ){
if (hit.moveDirection.y > 0.01f)
return;
// Make sure we are really standing on a straight platform
// Not on the underside of one and not falling down from it either!
if (hit.moveDirection.y < -0.9f && hit.normal.y > 0.9f) {
activePlatform = hit.collider.transform;
}
}
// Various helper functions below:
public float GetSpeed (){
return movement.speed;
}
public Vector3 GetVelocity (){
return movement.velocity;
}
public bool IsMoving (){
return movement.isMoving;
}
public bool IsJumping (){
return jump.jumping;
}
public bool IsTouchingCeiling (){
return (movement.collisionFlags & CollisionFlags.CollidedAbove) != 0;
}
public Vector3 GetDirection (){
return movement.direction;
}
public float GetHangTime (){
return movement.hangTime;
}
void Reset (){
gameObject.tag = "Player";
}
void SetControllable ( bool controllable ){
canControl = controllable;
}
// Require a character controller to be attached to the same game object
//@script RequireComponent (CharacterController)
//@script AddComponentMenu ("2D Platformer/Platformer Controller")
}
Well it means that movement is null. Where do you initialize/assign a value to movement?
It is hard to say how this problem should be fixed without seeing both (complete) scripts. It appears that 'movement' is not initialized. From what we see here, it is hard to see how it should be initialized.
Answer by robertbu · Apr 22, 2013 at 04:15 AM
You declare movement on line 71, but you don't initialize it do it is NULL when you try and access it in Awake(). Since you made the variable public, I'm not sure how you want this handled. The solution may be as simple as:
public PlatformerControllerMovement movement = new PlatformerControllerMovement();
Answer by MRollins · Apr 22, 2013 at 05:33 AM
THANKS! I'm a C# novice so I didn;t even notice it wasn't initialized and that would cause this error.