Unity 【Wheel Collider】实现游戏中的车具控制

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我是靠谱客的博主正直航空，最近开发中收集的这篇文章主要介绍Unity 【Wheel Collider】实现游戏中的车具控制，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

Wheel Collider专门用于模拟车具轮胎的物理属性，内置了碰撞检测、轮胎摩擦模型等，可以用于实现车具的控制。

核心的几个变量：

motorTorque：驱动力，将其设为正值向前移动，负值向后移动

brakeTorque：制动力，该值为正

rpm：车轮转速，注意它是每分钟转动多少圈

steerAngle：转向角度，可以实现车具的转弯

mass：车轮的重量，单位kg

radius：车轮的半径

forwardFriction：车轮在正向转动时的摩擦力

sidewaysFriction：车轮在侧向转动时的摩擦力

了解了这几个核心变量后，下面简单实现车具的控制：

1.首先给车具模型添加刚体组件，假设重量为2吨，将Mass设为2000：

2.为每个车轮模型添加一个空父级，添加Wheel Collider组件，假设每个轮胎的重量为20kg：

3.注意Wheel Collider碰撞器不能被车身的碰撞器包裹，否则车子不会移动。另外注意如果没有给车身添加Rigybody组件的话，Scene窗口也是看不到Wheel Collider的。

4.为Wheel Collider添加motorTorque驱动力，声明一个float类型的变量，暂定为200f，假设车辆为后驱，给两个后轮添加驱动力：

[SerializeField] private float motorTorque = 200f;

float verticalInput = Input.GetAxisRaw("Vertical");
//驱动
rlWheelCollider.motorTorque = verticalInput * motorTorque;
rrWheelCollider.motorTorque = verticalInput * motorTorque;

5.车辆移动时，使车轮模型滚动，滚动的角度通过Wheel Collider组件的rpm属性获取，上面提到该属性代表车轮每分钟转动多少圈，因此我们将其除以60，代表每秒钟转动的圈数，1圈为360度，因此再乘以360即可获得要滚动的角度：

//车轮模型滚动
flWheelTransform.Rotate(flWheelCollider.rpm / 60 * 360 * Time.deltaTime * Vector3.right);
frWheelTransform.Rotate(frWheelCollider.rpm / 60 * 360 * Time.deltaTime * Vector3.right);
rlWheelTransform.Rotate(rlWheelCollider.rpm / 60 * 360 * Time.deltaTime * Vector3.right);
rrWheelTransform.Rotate(rrWheelCollider.rpm / 60 * 360 * Time.deltaTime * Vector3.right);

6.为Wheel Collider添加转向，声明一个float类型变量来限制车轮最大的转动角度：

[SerializeField] private float maxSteerAngle = 45f;

float horizontalInput = Input.GetAxisRaw("Horizontal");
//转向
flWheelCollider.steerAngle = horizontalInput * maxSteerAngle;
frWheelCollider.steerAngle = horizontalInput * maxSteerAngle;

steerAngle仅仅是Wheel Collider的转向角度，还需要调整车轮实际模型的转向角度：

//车轮模型转向
flWheelCollider.transform.localEulerAngles = new Vector3(0f, flWheelCollider.steerAngle, 0f);
frWheelCollider.transform.localEulerAngles = new Vector3(0f, frWheelCollider.steerAngle, 0f);

7.通过brakeTorque属性实现刹车制动功能，假设按下Space空格键时进行刹车：

//刹车
bool isBraking = Input.GetKey(KeyCode.Space);
rlWheelCollider.brakeTorque = isBraking ? brakeTorque : 0f;
rrWheelCollider.brakeTorque = isBraking ? brakeTorque : 0f;

8.还要注意Rigybody组件的centerOfMass位置需要设为车身的底部：

最终代码：

using UnityEngine;

public class VehicleController : MonoBehaviour
{
    [SerializeField] private WheelCollider flWheelCollider;
    [SerializeField] private WheelCollider frWheelCollider;
    [SerializeField] private WheelCollider rlWheelCollider;
    [SerializeField] private WheelCollider rrWheelCollider;

    [SerializeField] private Transform flWheelTransform;
    [SerializeField] private Transform frWheelTransform;
    [SerializeField] private Transform rlWheelTransform;
    [SerializeField] private Transform rrWheelTransform;

    [SerializeField] private Transform centerOfMass;
    [SerializeField] private float motorTorque = 200f;
    [SerializeField] private float brakeTorque = 200f;
    [SerializeField] private float maxSteerAngle = 45f;

    private void Start()
    {
        GetComponent<Rigidbody>().centerOfMass = centerOfMass.localPosition;
    }
    private void Update()
    {
        float verticalInput = Input.GetAxisRaw("Vertical");
        float horizontalInput = Input.GetAxisRaw("Horizontal");

        //驱动
        rlWheelCollider.motorTorque = verticalInput * motorTorque;
        rrWheelCollider.motorTorque = verticalInput * motorTorque;
        //转向
        flWheelCollider.steerAngle = horizontalInput * maxSteerAngle;
        frWheelCollider.steerAngle = horizontalInput * maxSteerAngle;

        //车轮模型转动
        flWheelTransform.Rotate(flWheelCollider.rpm * 360 * Time.deltaTime * Vector3.right);
        frWheelTransform.Rotate(frWheelCollider.rpm * 360 * Time.deltaTime * Vector3.right);
        rlWheelTransform.Rotate(rlWheelCollider.rpm * 360 * Time.deltaTime * Vector3.right);
        rrWheelTransform.Rotate(rrWheelCollider.rpm * 360 * Time.deltaTime * Vector3.right);
        //车轮模型转向
        flWheelCollider.transform.localEulerAngles = new Vector3(0f, flWheelCollider.steerAngle, 0f);
        frWheelCollider.transform.localEulerAngles = new Vector3(0f, frWheelCollider.steerAngle, 0f);

        //刹车
        bool isBraking = Input.GetKey(KeyCode.Space);
        rlWheelCollider.brakeTorque = isBraking ? brakeTorque : 0f;
        rrWheelCollider.brakeTorque = isBraking ? brakeTorque : 0f;
    }
}