如何避免播放器跳过物体？

Question

When my player jumps in front of an object it will just jump right through it and I don't know how to fix it. I know it is because I am using transform to move my player but this has been the easiest way for it to jump so I don't want to change that. Here is my code to move my player:

using UnityEngine;
using System.Collections;

public class MovePlayer : MonoBehaviour
{   
    private Vector3 newPos;
    private Vector3 up = new Vector3 (0, .3f, 0);
    private bool jumping = false;
    public Rigidbody rigidbody;

    void Start(){
        rigidbody = GetComponent<Rigidbody> ();
    }

    void Update(){
        rigidbody.freezeRotation = true;

        if (!jumping) {
            if (Input.GetKeyDown (KeyCode.UpArrow)) {
                newPos = Vector3.forward + transform.position;
                transform.rotation = Quaternion.Euler (0, 0, 0);
                transform.position = (newPos);
                transform.position = newPos + up;               
            } 
            if (Input.GetKeyDown (KeyCode.DownArrow)) {
                newPos = Vector3.back + transform.position;
                transform.rotation = Quaternion.Euler (0, 180, 0);
                transform.position = (newPos);
                transform.position = newPos + up;
            }

            if (Input.GetKeyDown (KeyCode.RightArrow)) {
                newPos = Vector3.right + transform.position;
                transform.rotation = Quaternion.Euler (0, 90, 0);
                transform.position = (newPos);
                transform.position = newPos + up;
            }
            if (Input.GetKeyDown (KeyCode.LeftArrow)) {
                newPos = Vector3.left + transform.position;
                transform.rotation = Quaternion.Euler (0, -90, 0);
                transform.position = (newPos);
                transform.position = newPos + up;
            }               
        }
    }

    void OnCollisionEnter(Collision other)
    {
        if (other.gameObject.CompareTag ("Ground")) 
            jumping = false;
    }

    void OnCollisionExit(Collision other)
    {
        if (other.gameObject.CompareTag("Ground"))
            jumping = true;
    }
}

Answer 1

Your problem is that you are applying a transform on the player position - you really need to calculate a route from the current position to the destination implied by the transformation, and then do collision detection on every intermediate point.

This is a problem with many examples on the web, but googling Unity Collision Detection will suggest a lot of examples.

Answer 2

Since this is a GameObject with Rigidbody attached to it, and you want to detect collision while moving it, you must use the MovePosition and MoveRotation functions instead of moving its transform component directly.

So, code such as transform.position = newPos + up; and transform.rotation = Quaternion.Euler (0, 180, 0); must changed to rigidbody.MovePosition(newPos + up); and rigidbody.MoveRotation(Quaternion.Euler(0, 180, 0)); .

Enable Rigidbody Interpolation to move the GameObject smoothly. Also, isKinematic must be true/enabled or else, using MovePosition and MoveRotation will be useless just like moving Rigidbody by transform.position ...

public class MovePlayer : MonoBehaviour
{
    private Vector3 newPos;
    private Vector3 up = new Vector3(0, .3f, 0);
    private bool jumping = false;
    public Rigidbody rigidbody;

    void Start()
    {
        rigidbody = GetComponent<Rigidbody>();
    }

    void Update()
    {
        rigidbody.freezeRotation = true;

        if (!jumping)
        {
            if (Input.GetKeyDown(KeyCode.UpArrow))
            {
                newPos = Vector3.forward + transform.position;
                rigidbody.MoveRotation(Quaternion.Euler(0, 0, 0));
                rigidbody.MovePosition(newPos);
                rigidbody.MovePosition(newPos + up);
            }
            if (Input.GetKeyDown(KeyCode.DownArrow))
            {
                newPos = Vector3.back + transform.position;
                rigidbody.MoveRotation(Quaternion.Euler(0, 180, 0));
                rigidbody.MovePosition(newPos);
                rigidbody.MovePosition(newPos + up);
            }

            if (Input.GetKeyDown(KeyCode.RightArrow))
            {
                newPos = Vector3.right + transform.position;
                rigidbody.MoveRotation(Quaternion.Euler(0, 90, 0));
                rigidbody.MovePosition(newPos);
                rigidbody.MovePosition(newPos + up);
            }
            if (Input.GetKeyDown(KeyCode.LeftArrow))
            {
                newPos = Vector3.left + transform.position;
                rigidbody.MoveRotation(Quaternion.Euler(0, -90, 0));
                rigidbody.MovePosition(newPos);
                rigidbody.MovePosition(newPos + up);
            }
        }
    }

    void OnCollisionEnter(Collision other)
    {
        if (other.gameObject.CompareTag("Ground"))
            jumping = false;
    }

    void OnCollisionExit(Collision other)
    {
        if (other.gameObject.CompareTag("Ground"))
            jumping = true;
    }
}