在Unity中对角移动平台时如何防止物体滑动？

Question

我正在尝试在 Unity 中实现一个简单的叉车。向左、向右、向上和向下移动工作正常： Box stays in place

同时向左/向右和向上/向下移动（盒子沿对角线移动）盒子从叉子上滑落： Box is sliding off

有人有想法吗？

我已经尝试过的事情：

• 拿起箱子时，将其设为叉车的孩子
• 为叉子和盒子添加具有高摩擦力的二维物理材料
• 将箱子的 x 速度设置为叉车的 x 速度
• 降低叉车的移动和提升速度
• 减少项目设置中的固定时间戳
• 增加盒子的质量和重力比例

叉车和箱子都有一个 rigidbody2D，带有 Body Type Dynamic 和 Collision Detection Continuous。

目前我正在使用以下代码移动叉车：

private void FixedUpdate()
    {
        //Moving Left/Right
        if (moveRight)
        {
            timeElapsedDeceleration = 0;
            rb.velocity = new Vector2(Mathf.Lerp(rb.velocity.x, drivingSpeed, timeElapsedAcceleration / 2), rb.velocity.y);
            timeElapsedAcceleration += Time.fixedDeltaTime;
        }
        else if (moveLeft)
        {
            timeElapsedDeceleration = 0;
            rb.velocity = new Vector2(Mathf.Lerp(rb.velocity.x, -drivingSpeed, timeElapsedAcceleration / 2), rb.velocity.y);
            timeElapsedAcceleration += Time.fixedDeltaTime;
        }
        else
        {
            timeElapsedAcceleration = 0;
            rb.velocity = new Vector2(Mathf.Lerp(rb.velocity.x, 0, timeElapsedDeceleration / 2), rb.velocity.y);
            timeElapsedDeceleration += Time.fixedDeltaTime;
        }

        //Lifting
        if (moveForksUp && forks.transform.localPosition.y <= maxLiftHeight)
        {
            forks.transform.localPosition = new Vector2(forks.transform.localPosition.x, forks.transform.localPosition.y + liftingSpeed * Time.fixedDeltaTime);
            liftableMast.transform.localPosition = new Vector2(liftableMast.transform.localPosition.x, liftableMast.transform.localPosition.y + liftingSpeed / 1.5f * Time.fixedDeltaTime);
        }
        else if (moveForksDown && forks.transform.localPosition.y >= minLiftHeight)
        {
            forks.transform.localPosition = new Vector2(forks.transform.localPosition.x, forks.transform.localPosition.y - liftingSpeed * Time.fixedDeltaTime);
            liftableMast.transform.localPosition = new Vector2(liftableMast.transform.localPosition.x, liftableMast.transform.localPosition.y - liftingSpeed / 1.5f * Time.fixedDeltaTime);
        }
    }

箱子在移动时不应滑落，例如左右同时。

Answer 1

您可以使用物理学来防止箱子从叉车上滑落。您可以向盒子添加一个刚体，并设置其约束，使其只能沿 x 轴或 y 轴移动，但不能同时沿两者移动。

这是如何实现的示例：

public class BoxController : MonoBehaviour
{
  // The speed at which the box moves
  public float speed = 1.0f;

  // The rigidbody component attached to the box
  private Rigidbody rb;

  // Start is called before the first frame update
  void Start()
  {
    rb = GetComponent<Rigidbody>();

    // Set the constraints on the rigidbody so that it
    // can only move along the x-axis or y-axis, but not both
    rb.constraints = RigidbodyConstraints.FreezePositionZ |
                     RigidbodyConstraints.FreezeRotationX |
                     RigidbodyConstraints.FreezeRotationY;
  }

  // Update is called once per frame
  void Update()
  {
    // Get the horizontal and vertical input from the user
    float horizontalInput = Input.GetAxis("Horizontal");
    float verticalInput = Input.GetAxis("Vertical");

    // Apply the input as a force to the rigidbody
    rb.AddForce(new Vector3(horizontalInput, verticalInput, 0) * speed);
  }
}