随机移动脚本导致 Unity 冻结

Question

I have a grid consisting of 16 tiles. Now basically I want the user to find a path to the final location by moving randomly on the choices he has within the grid.

As of now I managed to create the functions for moving a step up, down, left and right. The issue arises when I'm trying to code in random movement. Ideally this is setup in a way that he can't go off bounds from the grid.

This is what I got going:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;


public class Move : MonoBehaviour

{
    void Up()
    {
        //get the Input from Horizontal axis
        float horizontalInput = Input.GetAxis("Horizontal");
        //get the Input from Vertical axis
        float verticalInput = Input.GetAxis("Vertical");

        //update the position
        transform.position = transform.position + new Vector3(0, 1.5f, 0);

        //output to log the position change
        Debug.Log(transform.position);
    }

    void Down()
    {
        //get the Input from Horizontal axis
        float horizontalInput = Input.GetAxis("Horizontal");
        //get the Input from Vertical axis
        float verticalInput = Input.GetAxis("Vertical");

        //update the position
        transform.position = transform.position + new Vector3(0, -1.5f, 0);

        //output to log the position change
        Debug.Log(transform.position);
    }

    void Left()
    {
        //get the Input from Horizontal axis
        float horizontalInput = Input.GetAxis("Horizontal");
        //get the Input from Vertical axis
        float verticalInput = Input.GetAxis("Vertical");

        //update the position
        transform.position = transform.position + new Vector3(-1.5f, 0, 0);

        //output to log the position change
        Debug.Log(transform.position);
    }

    void Right()
    {
        //get the Input from Horizontal axis
        float horizontalInput = Input.GetAxis("Horizontal");
        //get the Input from Vertical axis
        float verticalInput = Input.GetAxis("Vertical");

        //update the position
        transform.position = transform.position + new Vector3(1.5f, 0, 0);

        //output to log the position change
        Debug.Log(transform.position);
    }



    void Start()
    {
        var finalLocation = new Vector3(-0.5f, 0.5f, 0);
        var currentLocation = transform.position;

        while (currentLocation != finalLocation)
        {
            int randomNum = Random.Range(0, 3);

            if (randomNum == 0)
            {
                Up();
            }
            else if (randomNum == 1)
            {
                Down();
            }
            else if (randomNum == 2)
            {
                Left();
            }
            else if (randomNum == 3)
            {
                Right();
            }

        }
    }
}

UPDATED WORKING CODE:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;


public class Move : MonoBehaviour

{
    void Up()
    {
        //update the position
        transform.position = transform.position + new Vector3(0, 1.5f, 0);

        //output to log the position change
        Debug.Log(transform.position);
    }

    void Down()
    {
        //update the position
        transform.position = transform.position + new Vector3(0, -1.5f, 0);

        //output to log the position change
        Debug.Log(transform.position);
    }

    void Left()
    {
        //update the position
        transform.position = transform.position + new Vector3(-1.5f, 0, 0);

        //output to log the position change
        Debug.Log(transform.position);
    }

    void Right()
    {
        //update the position
        transform.position = transform.position + new Vector3(1.5f, 0, 0);

        //output to log the position change
        Debug.Log(transform.position);
    }



    void Update()
    {
        var finalLocation = new Vector3(2.5f, 2.0f, -2.0f);
        var currentLocation = transform.position; 
        int randomNum = Random.Range(0, 4);

        if (currentLocation != finalLocation) { 
                if (randomNum == 0)
            {
                Up();
            }
            else if (randomNum == 1)
            {
                Down();
            }
            else if (randomNum == 2)
            {
                Left();
            }
            else if (randomNum == 3)
            {
                Right();
            }
            return;
        }
    }
}

My last issue is how I can limit this randomness to only stick to the grid and not go off grid. Any thoughts?

Answer 1

Several problems:

1. Your object is stuck in an endless while loop because it isn't allowed to exit (and do things like render the frame, take input from the user, etc) until your random movement script reaches its finalLocation . You aren't giving the game time to do anything else.
   You almost certainly want this to be a coroutine or an Update function.
2. Random.Range returns an int in the range min (inclusive) to max (exclusive), so your call to it will never return 3 .

Answer 2

Here are some problems:

• horizontalInput and verticalInput are never used inside your functions

• while(currentLocation != finalLocation) This condition can fail in some situations. Unity uses float for the coordinates, meaning it needs to be exactly on the same position, every decimal place need to be the same.

• Random.Range(0, 3) will return a random number between 0 (inclusive) and 3 (exclusive), so the only possible values will be 0, 1 and 2. The script will never call the Right() function.

Unity uses one thread to run your scripts by default, if you put a while loop to move the object to a location it will freeze the entire game till the object is at the proper place. I recommend you to use the Update() function, it gets called every frame.