夾緊剛體 2D 控制器

Question

我有一個處理船舶控制的類，我想在 y 軸上夾緊位置。

 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;
}
}

非常感謝您提前。

Answer 1

每當處理Rigidbody或Rigidbody2D ，有兩個主要規則

1. 不要做的事情Update而是FixedUpdate其用於所有物理和Physics2D引擎相關的計算。

   在Update移動對象會導致一些抖動並阻止物理反應，如碰撞等。

2. 不要直接通過Transform組件，而是使用Rigidbody或Rigidbody2D屬性和方法！

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

   再次通過Transform組件移動對象會破壞物理

所以你的代碼應該像

// 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，您也可以簡單地將這個新速度直接分配給剛體

// 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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在智能手機上打字，但我希望這個想法變得清晰