如何在Unity2D中强制拖放对象 [英] How to Drag and throw object forcefully in Unity2D

问题描述

我是Unity 2D的新手，我想拖动&强行扔掉我的游戏对象.基本上，我有三个游戏对象，当我将任何人拖离然后向上时，我应该向该方向强行抛掷.

I'm new in Unity 2D i want to drag & throw my game object forcefully. basically i have three game object and when i drag anyone off then to upward i should be throw forcefully on that direction.

谁能告诉我该怎么做?

我已经尝试过此代码，但是当我要单击以拖动游戏对象时，它会直接引发而不拖动它.

i have tried this code but when i'm going to click to drag my game object then it throws directly without dragging it.

这是我的代码

private Rigidbody2D rb;
private float jumpForce = 700f;
private bool jumpAllowed = false;

float deltaX, deltaY;

string button_name = "";

// Use this for initialization
private void Start () 
{
    Debug.Log("Started");
    rb = GetComponent<Rigidbody2D> ();
    PhysicsMaterial2D mat = new PhysicsMaterial2D();
    mat.bounciness = 0.75f;
    mat.friction = 0.4f;
    GetComponent<CircleCollider2D>().sharedMaterial = mat;
}

// Update is called once per frame
private void Update () 
{
    Debug.Log("Update");

    if (Input.touchCount > 0)
    {
        Touch touch = Input.GetTouch(0);
        Vector2 touchPos = Camera.main.ScreenToWorldPoint(touch.position);

        switch (touch.phase)
        {
            case TouchPhase.Began:
                if (GetComponent<Collider2D>() == Physics2D.OverlapPoint(touchPos))
                {
                    deltaX = touchPos.x - transform.position.x;
                    deltaY = touchPos.y - transform.position.y;
                    jumpAllowed = true;
                    rb.freezeRotation = true;
                    rb.velocity = new Vector2(0, 0);
                    rb.gravityScale = 0;
                    GetComponent<Collider2D>().sharedMaterial = null;
                }
                break;

            case TouchPhase.Moved:
                if (GetComponent<Collider2D>() == Physics2D.OverlapPoint(touchPos) && jumpAllowed)
                {
                    rb.MovePosition(new Vector2(touchPos.x - deltaX, touchPos.y - deltaY));
                }
                break;

            case TouchPhase.Ended:
                jumpAllowed = false;
                rb.freezeRotation = false;
                rb.gravityScale = 2;
                PhysicsMaterial2D mat = new PhysicsMaterial2D();
                mat.bounciness = 0.75f;
                mat.friction = 0.4f;
                GetComponent<CircleCollider2D>().sharedMaterial = mat;
                break;
        }
    }
}

推荐答案

首先，有一个错误

rb.MovePosition(new Vector2(touchPos.x - deltaX, touchPos.y - deltaY));

应该是

rb.MovePosition(new Vector2(touchPos.x + deltaX, touchPos.y + deltaY));

还有另一个问题，MovePosition根本不影响物体速度.如果您停止使用MovePosition，则该对象将掉落而不会保留前一动作的任何能量.

There's also another issue, MovePosition doesn't affect the object velocity at all. If you stop using MovePosition, the object will just fall without keeping any energy from the previous movement.

您可以简单地存储每个动作的前一个位置，并在TouchPhase.Ended上执行此操作:

You could simply store the previous position every movement, and do this on TouchPhase.Ended:

rb.velocity = (rb.position - prevPosition) / Time.deltaTime;

简单地说，这将计算完成最后一个运动所需的速度，并将其应用于刚体.

Simply put, this calculates the velocity that was required to accomplish the last movement, and apply it to the rigidbody.

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