夹紧刚体2D控制器

Question

我有一个处理船控制的类，我想在 y 轴上固定位置。

 public class ControlledRigidbody2D : MonoBehaviour
{
public float verticalInputAcceleration = 1;
public float horizontalInputAcceleration = 20;
public float maxSpeed = 10;
public float velocityDrag = 1;
private Vector3 velocity;
private void Update()
{
    Vector3 acceleration = Input.GetAxis("Vertical") * verticalInputAcceleration * transform.up;
    velocity.y += acceleration.y * Time.deltaTime;
    Vector3 accelerationRight = Input.GetAxis("Horizontal") * horizontalInputAcceleration * transform.right;
    velocity.x += accelerationRight.x * Time.deltaTime; ;
    velocity = velocity * (1 - Time.deltaTime * velocityDrag);
    velocity = Vector3.ClampMagnitude(velocity, maxSpeed);
    transform.position += velocity * Time.deltaTime;
}
}

非常感谢您。

Answer 1

在处理Rigidbody 或Rigidbody2D 时，有两个主要规则

1. 不要在Update 中做事，而是在FixedUpdate 中做事，它用于所有物理和Physics2D 引擎相关的计算。

   在Update 中移动对象会导致一些抖动并阻碍物理反应，如碰撞等。

2. 不要直接通过Transform 组件，而是使用Rigidbody 或Rigidbody2D 的属性和方法！

   就像你的情况 Rigidbody2D.MovePosition 或 Rigidbody2D.velocity

   再次通过Transform 组件移动对象会破坏物理

所以你的代码应该是这样的

// already reference the component via the Inspector
[SerializeField] Rigidbody2D rb;

Vector3 acceleration;
Vector3 accelerationRight;

privtae void Awake()
{
    if(!rb) rb = GetComponent<Rigidbody2D>();
}

// Get user input within Update
private void Update()
{
    acceleration = Input.GetAxis("Vertical") * verticalInputAcceleration * transform.up;
    accelerationRight = Input.GetAxis("Horizontal") * horizontalInputAcceleration * transform.right;
}

// update the Rigidbody in FixedUpdate
private void FixedUpdate()
{
    velocity = rb.velocity;

    // do these here so Time.deltaTime uses the correct value
    velocity += acceleration * Time.deltaTime;
    velocity += accelerationRight * Time.deltaTime;
    velocity = velocity * (1 - Time.deltaTime * velocityDrag);
    velocity = Vector3.ClampMagnitude(velocity, maxSpeed);

    // Problem: MovePosition expects a value in global world space
    // so if your velocity is in local space 
    // - which seems to be the case  - you will have to convert 
    // it into a global position first
    var newPosition = rb.position + transform.TransformDirection(velocity  * Time.deltaTime);
    rb.MovePosition(newPosition);
}

或者您也可以直接将这个新速度分配给刚体

// update the Rigidbody in FixedUpdate
private void FixedUpdate()
{
    velocity = rb.velocity;

    // do these here so Time.deltaTime uses the correct value
    velocity += acceleration * Time.deltaTime;
    velocity += accelerationRight * Time.deltaTime;
    velocity = velocity * (1 - Time.deltaTime * velocityDrag);
    velocity = Vector3.ClampMagnitude(velocity, maxSpeed);

    rb.velocity = velocity;
}

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在智能手机上输入，但我希望思路清晰