我正在使用Unity版本5.6.1f1,如果有帮助的话。
在我实例化Zombie
的随机时刻,它导致NullReferenceException
指向ThirdPersonController.cs
。但是,这个GameObject和脚本是由Unity构建的标准字符包资产。我所做的只是通过脚本附加,Zombie.target
附加到Player.transform
有些僵尸按预期追逐Player
,但有些则没有。
Unity论坛上出现此错误,找到的唯一解决方案是删除指向ThirdPersonCharacter.CheckGroundStatus()
的FSM,或者未分配动画师。
错误:
NullReferenceException: Object reference not set to an instance of an object
UnityStandardAssets.Characters.ThirdPerson.ThirdPersonCharacter.CheckGroundStatus () (at Assets/Standard Assets/Characters/ThirdPersonCharacter/Scripts/ThirdPersonCharacter.cs:215)
UnityStandardAssets.Characters.ThirdPerson.ThirdPersonCharacter.Move (Vector3 move, Boolean crouch, Boolean jump) (at Assets/Standard Assets/Characters/ThirdPersonCharacter/Scripts/ThirdPersonCharacter.cs:54)
UnityStandardAssets.Characters.ThirdPerson.AICharacterControl.Update () (at Assets/Standard Assets/Characters/ThirdPersonCharacter/Scripts/AICharacterControl.cs:39)
ThirdPersonCharacter,相关部分:
if (Physics.Raycast(transform.position + (Vector3.up * 0.1f), Vector3.down, out hitInfo, m_GroundCheckDistance))
{
m_GroundNormal = hitInfo.normal;
m_IsGrounded = true;
m_Animator.applyRootMotion = true; //ERROR HERE
}
完整脚本(Unity提供的资产):
using UnityEngine;
namespace UnityStandardAssets.Characters.ThirdPerson
{
[RequireComponent(typeof(Rigidbody))]
[RequireComponent(typeof(CapsuleCollider))]
[RequireComponent(typeof(Animator))]
public class ThirdPersonCharacter : MonoBehaviour
{
[SerializeField] float m_MovingTurnSpeed = 360;
[SerializeField] float m_StationaryTurnSpeed = 180;
[SerializeField] float m_JumpPower = 12f;
[Range(1f, 4f)][SerializeField] float m_GravityMultiplier = 2f;
[SerializeField] float m_RunCycleLegOffset = 0.2f; //specific to the character in sample assets, will need to be modified to work with others
[SerializeField] float m_MoveSpeedMultiplier = 1f;
[SerializeField] float m_AnimSpeedMultiplier = 1f;
[SerializeField] float m_GroundCheckDistance = 0.1f;
Rigidbody m_Rigidbody;
Animator m_Animator;
bool m_IsGrounded;
float m_OrigGroundCheckDistance;
const float k_Half = 0.5f;
float m_TurnAmount;
float m_ForwardAmount;
Vector3 m_GroundNormal;
float m_CapsuleHeight;
Vector3 m_CapsuleCenter;
CapsuleCollider m_Capsule;
bool m_Crouching;
void Start()
{
m_Animator = GetComponent<Animator>();
m_Rigidbody = GetComponent<Rigidbody>();
m_Capsule = GetComponent<CapsuleCollider>();
m_CapsuleHeight = m_Capsule.height;
m_CapsuleCenter = m_Capsule.center;
m_Rigidbody.constraints = RigidbodyConstraints.FreezeRotationX | RigidbodyConstraints.FreezeRotationY | RigidbodyConstraints.FreezeRotationZ;
m_OrigGroundCheckDistance = m_GroundCheckDistance;
void CheckGroundStatus()
{
RaycastHit hitInfo;
#if UNITY_EDITOR
// helper to visualise the ground check ray in the scene view
Debug.DrawLine(transform.position + (Vector3.up * 0.1f), transform.position + (Vector3.up * 0.1f) + (Vector3.down * m_GroundCheckDistance));
#endif
// 0.1f is a small offset to start the ray from inside the character
// it is also good to note that the transform position in the sample assets is at the base of the character
if (Physics.Raycast(transform.position + (Vector3.up * 0.1f), Vector3.down, out hitInfo, m_GroundCheckDistance))
{
m_GroundNormal = hitInfo.normal;
m_IsGrounded = true;
m_Animator.applyRootMotion = true; //ERROR HERE
}
else
{
m_IsGrounded = false;
m_GroundNormal = Vector3.up;
m_Animator.applyRootMotion = false;
}
}
}
}
AICharacterControl:
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
namespace UnityStandardAssets.Characters.ThirdPerson
{
[RequireComponent(typeof (UnityEngine.AI.NavMeshAgent))]
[RequireComponent(typeof (ThirdPersonCharacter))]
public class AICharacterControl : MonoBehaviour
{
public UnityEngine.AI.NavMeshAgent agent { get; private set; } // the navmesh agent required for the path finding
public ThirdPersonCharacter character { get; private set; } // the character we are controlling
public Transform target; // target to aim for
private GameObject player;
private void Start()
{
// get the components on the object we need ( should not be null due to require component so no need to check )
agent = GetComponentInChildren<UnityEngine.AI.NavMeshAgent>();
character = GetComponent<ThirdPersonCharacter>();
player = GameObject.FindGameObjectWithTag("Player");
target = player.transform;
agent.updateRotation = false;
agent.updatePosition = true;
}
private void Update()
{
if (target != null)
agent.SetDestination(target.position);
if (agent.remainingDistance > agent.stoppingDistance)
character.Move(agent.desiredVelocity, false, false);
else
character.Move(Vector3.zero, false, false);
}
public void SetTarget(Transform target)
{
this.target = target;
}
}
}
答案 0 :(得分:1)
尝试在ThirdPersonCharacter.cs中将“void Start”替换为“void Awake”。
当将ThirdPersonCharacter.cs与另一个AI行为脚本一起使用时,我遇到了一个非常类似的问题:在编辑器中工作得很好,但是一旦我构建它,我就得到了null引用异常,无论是在构建还是在编辑。我无法在网上找到任何东西,空引用异常错误很常见,但大多数情况下你通过修复一个变量解决它们...我是c#的相对新手,但我认为这不是一般问题使用脚本,但调用/初始化变量的方式。无论如何,这对我有用。
https://docs.unity3d.com/ScriptReference/MonoBehaviour.Awake.html