使用 Unity 和 c# 时，如何使对象运动不那么断断续续且更加流畅？

Question

I'm trying to make a simple snake game on unity that can be played on a mobile device. I got to the point where the snakes head is able to move continuously in the direction that the user swiped in, but the movement of the snake's head is kind of choppy and I'd like it to be more fluid.

I have this in the public class:

Vector2 dir = Vector2.right;

My start function looks like this:

void Start() {

    dragDistance = Screen.height * 5 / 100; //dragDistance is 5% height of the screen
    InvokeRepeating("Move", 0.3f, 0.075f);

}

Inside of my Update function I have this:

if (Mathf.Abs(lp.x - fp.x) > dragDistance || Mathf.Abs(lp.y - fp.y) > dragDistance)
            {//It's a drag
             //check if the drag is vertical or horizontal
                if (Mathf.Abs(lp.x - fp.x) > Mathf.Abs(lp.y - fp.y))
                {   //If the horizontal movement is greater than the vertical movement...
                    if ((lp.x > fp.x))  //If the movement was to the right)
                    {   //Right swipe
                        dir = Vector2.right;
                    }
                    else
                    {   //Left swipe
                        dir = -Vector2.right;
                    }
                }
                else
                {   //the vertical movement is greater than the horizontal movement
                    if (lp.y > fp.y)  //If the movement was up
                    {   //Up swipe
                        dir = Vector2.up;
                    }
                    else
                    {   //Down swipe
                        dir = -Vector2.up;
                    }
                }
            }

And after the Update function I have:

void Move()
{
    // Move head into new direction
    transform.Translate(dir);
}

Thanks for your help.

Answer 1

This is simply due to how you are currently moving.
Using InvokeRepeating to move your character will be super choppy as you are just moving "forward" by a certain amount every time InvokeRepeating repeats.

You really shouldn't be using that to move your character. Typically you want to you some form of Rigidbody and physics to move. Perhaps try something like this :

public Rigidbody2D rb;

void FixedUpdate() {

  rb.MovePosition((rb.position + dir) * Time.fixedDeltaTime);

}

That could be a very simple answer. Check out some more details on that method here .
Also just try looking up some tutorials on movement in Unity.

Answer 2

The problem is you aren't moving every frame. You could fix this by moving in the update() like so:

transform.Translate(dir * speed * Time.deltaTime);

Instead of doing InvokeRepeating and Move().

But what if you want to make the snake stop at each square like it does now, but move smoothly from square to square? You would need to save the snake's next position in your move() function and then smoothly move the snake there in Update(). It would look something like this:

void Move()
{
    // Move head to next position
    prevSquare = transform.position;   // keep track of the previous square
                                       // so we can use lerp() later on
    nextSquare = transform.position + dir;
    progress = 0;     // progress is the percent distance between the two squares
    isMoving = true;  //we probably need isMoving so we can decide what to do if they
                      //swipe while snake is moving, I'll leave it to you to figure 
                      //out
}


update()
{
     ...

     if(isMoving)
     {
          progress = progress + time.deltaTime;
          transform.position = Vector2.Lerp(prevSquare, nextSquare, progress);
          if(progress > 1.0f)
          {
               isMoving = false;
          }
     }
}