performance - 快速移动物体2D游戏(Unity3d)

Question

我找到了官方的统一训练https://www.youtube.com/watch?v=D5MqLcO6A8g
并找到错误。（看分数）

我花了大约2天的时间修复它，但失败了。
我找到了“ DontGoThroughThings”脚本，并尝试重写以在2D中使用。再次失败）

请帮我！

这是重写脚本：

public LayerMask layerMask; //make sure we aren't in this layer 
public float skinWidth; //probably doesn't need to be changed 

private float minimumExtent; 
private float partialExtent; 
private float sqrMinimumExtent; 
private Vector2 previousPosition; 
private Rigidbody2D myRigidbody; 


//initialize values 
void Awake() 
{ 
    myRigidbody = GetComponent<Rigidbody2D>(); 
    previousPosition = myRigidbody.position;
    minimumExtent = Mathf.Min(Mathf.Min(GetComponent<Collider2D>().bounds.extents.x, GetComponent<Collider2D>().bounds.extents.y)); 
    partialExtent = minimumExtent * (1.0f - skinWidth); 
    sqrMinimumExtent = minimumExtent * minimumExtent; 
} 

void FixedUpdate() 
{ 
    //have we moved more than our minimum extent? 
    Vector2 movementThisStep = myRigidbody.position - previousPosition; 
    float movementSqrMagnitude = movementThisStep.sqrMagnitude;

    if (movementSqrMagnitude > sqrMinimumExtent) 
    { 
        float movementMagnitude = Mathf.Sqrt(movementSqrMagnitude);
        //RaycastHit2D hitInfo; 

        //check for obstructions we might have missed 
        if (Physics2D.Raycast(previousPosition, movementThisStep, movementMagnitude, 0, layerMask.value)) 
            myRigidbody.position = (movementThisStep/movementMagnitude)*partialExtent;
        Debug.DrawLine(myRigidbody.position, myRigidbody.position - previousPosition, Color.green);
    } 

    previousPosition = myRigidbody.position; 
}

这是unitypackage https://www.dropbox.com/s/a3n1dalbc1k0k42/Hat%20Trick.unitypackage?dl=0

附言对不起，我的英语，谢谢您的帮助！

Answer 1

说明

Unity中的连续碰撞检测不使用光线投射。结果，非常快速移动（和/或相对较小）的对象（现在将其称为projectile这种对象）仍然可以穿过物体，而不会检测到碰撞。著名的DontGoThroughThings组件可修复3D问题。有一些不一致之处，但是如果您知道自己在做什么，就可以完成工作。

这是我对其的2D改编。

我添加了一些功能，以使其对每个不太擅长编码或游戏物理的人都更加友好。

如何使用它


将此组件添加到快速移动的对象中，当它们碰到某些东西时，它们将始终触发OnTriggerEnter2D事件。
您也可以选择发送其他自定义消息（通过更改MessageName变量）。实际上，由于以下说明，我建议这样做。
发送消息是脚本的主要用例。它不会神奇地使弹丸在物理意义上正确表现。
triggerTarget变量确定是否将消息发送给自身（如果您将打击处理脚本附加到了弹丸上），发送给被打击的对象（如果您将打击处理附加到了应该被打击的对象上）被弹丸击中），或两者的任何变体。
与原始版本不同，此脚本还允许在可以通过momentumTransferFraction变量进行调整的冲击力上施加力。当两个物体碰撞时，产生的力是两个物体之间动量（质量乘以速度）传递的结果。我这样做的方法很初级，缺少很多促成因素，但是足以让弹丸在撞击时推动物体。就像在现实世界中一样，弹丸越快或越重，施加的力就越大。


还有一些警告（大多数也适用于原始版本）


仅适用于快速移动的物体。使用的次数越少越好，因为它比正常的碰撞检测要昂贵得多。
虽然碰撞检测更准确，但是碰撞分辨率只是非常基本的。它不如物理引擎默认执行的操作好。
在当前版本中，事后总是会发现冲突。这就是为什么您可能会在碰撞记录时看到弹丸穿过物体的原因。我想在不久的将来解决此问题。
如果您在诸如子弹或其他形式的弹丸之类的物体上使用此功能，而这些物体在第一次命中后基本上停止工作，则可以将momentumTransferFraction设置为1，以使子弹以物理方式推动该对象（通过将其所有动量应用于第一个命中的对象）而无需子弹本身会受到影响。
由于某些原因，您不能仅对一个对象禁用默认的碰撞检测。这意味着，如果您如此（不幸），并且碰巧通过Unity的默认冲突检查记录了碰撞，则可能对同一对象多次触发OnTriggerEnter2D，或者（如果碰撞器不是触发器）施加对命中目标施加强制作用（除了此脚本施加的目标外）。但是，由于这是随机的并且非常不一致，因此除了在弹丸的对撞机上打开IsTrigger之外，我建议使用自定义消息名称来处理弹丸的影响。这样，默认冲突检测随机检测到的冲突不会有任何意外的副作用[请记住，默认冲突检测对于此类对象不一致是您添加此脚本的实际原因]。仅供参考：从Unity 5开始，防止默认冲突检测的仅有两种方法是IgnoreCollision和IgnoreLayerCollision。


码

using UnityEngine;
using System.Collections;
using System.Linq;


/// <summary>
/// 2D adaption of the famous DontGoThroughThings component (http://wiki.unity3d.com/index.php?title=DontGoThroughThings).
/// Uses raycasting to trigger OnTriggerEnter2D events when hitting something.
/// </summary>
/// <see cref="http://stackoverflow.com/a/29564394/2228771"/>
public class ProjectileCollisionTrigger2D : MonoBehaviour {
    public enum TriggerTarget {
        None = 0,
        Self = 1,
        Other = 2,
        Both = 3
    }

    /// <summary>
    /// The layers that can be hit by this object.
    /// Defaults to "Everything" (-1).
    /// </summary>
    public LayerMask hitLayers = -1;

    /// <summary>
    /// The name of the message to be sent on hit.
    /// You generally want to change this, especially if you want to let the projectile apply a force (`momentumTransferFraction` greater 0).
    /// If you do not change this, the physics engine (when it happens to pick up the collision) 
    /// will send an extra message, prior to this component being able to. This might cause errors or unexpected behavior.
    /// </summary>
    public string MessageName = "OnTriggerEnter2D";

    /// <summary>
    /// Where to send the hit event message to.
    /// </summary>
    public TriggerTarget triggerTarget = TriggerTarget.Both;

    /// <summary>
    /// How much of momentum is transfered upon impact.
    /// If set to 0, no force is applied.
    /// If set to 1, the entire momentum of this object is transfered upon the first collider and this object stops dead.
    /// If set to anything in between, this object will lose some velocity and transfer the corresponding momentum onto every collided object.
    /// </summary>
    public float momentumTransferFraction = 0;

    private float minimumExtent;
    private float sqrMinimumExtent;
    private Vector2 previousPosition;
    private Rigidbody2D myRigidbody;
    private Collider2D myCollider;


    //initialize values 
    void Awake()
    {
        myRigidbody = GetComponent<Rigidbody2D>();
        myCollider = GetComponents<Collider2D> ().FirstOrDefault();
        if (myCollider == null || myRigidbody == null) {
            Debug.LogError("ProjectileCollisionTrigger2D is missing Collider2D or Rigidbody2D component", this);
            enabled = false;
            return;
        }

        previousPosition = myRigidbody.transform.position;
        minimumExtent = Mathf.Min(myCollider.bounds.extents.x, myCollider.bounds.extents.y);
        sqrMinimumExtent = minimumExtent * minimumExtent;
    }

    void FixedUpdate()
    {
        //have we moved more than our minimum extent? 
        var origPosition = transform.position;
        Vector2 movementThisStep = (Vector2)transform.position - previousPosition;
        float movementSqrMagnitude = movementThisStep.sqrMagnitude;

        if (movementSqrMagnitude > sqrMinimumExtent) {
            float movementMagnitude = Mathf.Sqrt(movementSqrMagnitude);

            //check for obstructions we might have missed 
            RaycastHit2D[] hitsInfo = Physics2D.RaycastAll(previousPosition, movementThisStep, movementMagnitude, hitLayers.value);

            //Going backward because we want to look at the first collisions first. Because we want to destroy the once that are closer to previous position
            for (int i = 0; i < hitsInfo.Length; ++i) {
                var hitInfo = hitsInfo[i];
                if (hitInfo && hitInfo.collider != myCollider) {
                    // apply force
                    if (hitInfo.rigidbody && momentumTransferFraction != 0) {
                        // When using impulse mode, the force argument is actually the amount of instantaneous momentum transfered.
                        // Quick physics refresher: F = dp / dt = m * dv / dt
                        // Note: dt is the amount of time traveled (which is the time of the current frame and is taken care of internally, when using impulse mode)
                        // For more info, go here: http://forum.unity3d.com/threads/rigidbody2d-forcemode-impulse.213397/
                        var dv = myRigidbody.velocity;
                        var m = myRigidbody.mass;
                        var dp = dv * m;
                        var impulse = momentumTransferFraction * dp;
                        hitInfo.rigidbody.AddForceAtPosition(impulse, hitInfo.point, ForceMode2D.Impulse);

                        if (momentumTransferFraction < 1) {
                            // also apply force to self (in opposite direction)
                            var impulse2 = (1-momentumTransferFraction) * dp;
                            hitInfo.rigidbody.AddForceAtPosition(-impulse2, hitInfo.point, ForceMode2D.Impulse);
                        }
                    }

                    // move this object to point of collision
                    transform.position = hitInfo.point;

                    // send hit messages
                    if (((int)triggerTarget & (int)TriggerTarget.Other) != 0 && hitInfo.collider.isTrigger) {
                        hitInfo.collider.SendMessage(MessageName, myCollider, SendMessageOptions.DontRequireReceiver);
                    }
                    if (((int)triggerTarget & (int)TriggerTarget.Self) != 0) {
                        SendMessage(MessageName, hitInfo.collider, SendMessageOptions.DontRequireReceiver);
                    }
                }
            }
        }

        previousPosition = transform.position = origPosition;
    }
}