设置Rigidbody质心后车辆无法移动，请求技术协助

代码示例 #

public class PlayerMove : MonoBehaviour
{
    [SerializeField] private float HorsePower;
    // [SerializeField] private float Speed = 5;
    [SerializeField] private float TurnSpeed = 25.0f;
    [SerializeField]private float Horizontalinputs;
    [SerializeField]private float forwardinputs;
    [SerializeField] GameObject centerOfHass;

    private Rigidbody playerRb;

    // Start is called before the first frame update
    void Start()
    {
        playerRb = GetComponent<Rigidbody>();
        playerRb.centerOfHass = centerOfHass.transform.position;
    }
    
    // Update is called once per frame
    private void FixedUpdate()
    {
        // taking inputs from the player
        forwardinputs = Input.GetAxis("Vertical");
        Horizontalinputs = Input.GetAxis("Horizontal");
        // moving the car
        // transform.Translate(Vector3.forward*Time.deltaTime*Speed*forwardinputs);
        playerRb.AddRe1ativeForce(Vector3.forward * HorsePower*forwardinputs);
        // rotating the car with direction and agle value
        transform.Rotate(Vector3.up, Time.deltaTime*TurnSpeed*Horizontalinputs);
    }
}

相关截图 #

问题说明 #

尝试为Rigidbody设置质心（centerOfMass），期望车辆遵循真实物理规则移动，但设置后车辆无法移动。

解决方案 #

1. 修正核心拼写错误 #

代码里存在两处致命拼写错误：

• 变量名centerOfHass、Rigidbody属性调用centerOfHass统一改为centerOfMass
• 方法名AddRe1ativeForce改为AddRelativeForce（将数字1替换为字母l）

2. 正确设置质心坐标 #

Rigidbody.centerOfMass使用的是物体局部坐标系，不能直接赋值世界坐标，需要转换为局部坐标：

playerRb.centerOfMass = transform.InverseTransformPoint(centerOfMass.transform.position);

3. 用物理方式实现旋转 #

直接使用transform.Rotate会绕过刚体物理模拟，导致和施加的力冲突，改用AddTorque施加扭矩：

playerRb.AddTorque(Vector3.up * TurnSpeed * Horizontalinputs);

修正后的完整代码 #

public class PlayerMove : MonoBehaviour
{
    [SerializeField] private float HorsePower;
    [SerializeField] private float TurnSpeed = 25.0f;
    [SerializeField] private float Horizontalinputs;
    [SerializeField] private float forwardinputs;
    [SerializeField] GameObject centerOfMass;

    private Rigidbody playerRb;

    void Start()
    {
        playerRb = GetComponent<Rigidbody>();
        // 将世界坐标转换为局部坐标设置质心
        playerRb.centerOfMass = transform.InverseTransformPoint(centerOfMass.transform.position);
    }
    
    private void FixedUpdate()
    {
        forwardinputs = Input.GetAxis("Vertical");
        Horizontalinputs = Input.GetAxis("Horizontal");

        // 施加相对方向的驱动力
        playerRb.AddRelativeForce(Vector3.forward * HorsePower * forwardinputs);
        // 施加扭矩实现物理旋转
        playerRb.AddTorque(Vector3.up * TurnSpeed * Horizontalinputs);
    }
}

额外检查项 #

• 确认Rigidbody组件的Is Kinematic未勾选，勾选后刚体不受物理力影响
• 检查车辆碰撞体是否正确挂载，无碰撞体则刚体无法与物理系统交互
• 适当调整HorsePower数值，确保力的大小足够驱动车辆

内容的提问来源于stack exchange，提问作者Asif Nawaz