C＃Unity-当我在游戏中单击空格键时，如何启用“ PlayerMovement”脚本和“使用重力”复选框（刚体）？

Question

I started making my first game a week ago and I've run into some problems with the coding. Basically, I have made a game where you play as a Ball. The goal is to dodge the obstacles and reach the end of the level.

I've made a respawner that puts the ball at the very beginning of the map whenever you die. My problem is that as soon as the ball has respawned it starts moving again.

What I have done so far to prevent the Ball from moving at the start is that I have DISABLED the Ball's PlayerMov script (player movement) and the checkbox "Use Gravity" in the Rigidbody component. So now my Ball is stuck at the start position unable to move.

So what do I need help with? I want the human player to press the spacebar in order for the ball's PlayerMov script and "Use Gravity" checkbox (in Rigidbody) to enable. So instead of having the ball immediately move after it has respawned, it will now wait for the human player to press the spacebar before starting.

The script you can see below is my EnableMovement script where I attempted to fix this issue. But something's wrong, and I'm not quite sure what it is.

Answer 1

You have to place it in update() method, so, the script will check every frames if the spacebar was pressed.

void Update()
{
    if (Input.GetKey(KeyCode.Space)) //notice the removing of the ;
    {
        GetComponent<PlayerMov>().enabled = true;
    }
}

There was a mistake in your code, when typing this :

if (Input.GetKey(KeyCode.Space)); //notice the ;
{
    GetComponent<PlayerMov>().enabled = true;
}

This is the same thing than :

if (Input.GetKey(KeyCode.Space))
    ; //Do nothing
//there is a scope that will be executed
{
    GetComponent<PlayerMov>().enabled = true;
}

and this is exactly the same than this :

if (Input.GetKey(KeyCode.Space))
{
    ; //Do nothing
}
//there is a scope that will be executed
{
    GetComponent<PlayerMov>().enabled = true;
}

Answer 2

Edit: My mistake, the property you want to change is not enabled for a Rigidbody . It is IsKinematic . Also you probably want to disable collisions too. I've edited my code below.

A simple solution could be to have the physics disabled when the game is run, and enable it when the player presses space. Setting the Rigidbody.IsKinematic property to true means the GameObject won't be affected by physics. That way you don't need to touch the gravity settings or disable the script.

Rigidbody _rigidbody;    

void Start() // or could go in the Awake() method depending on your game
{
    _rigidbody = GetComponent<Rigidbody>();
    TogglePhysics(false);
}

void Update()
{
    if (Input.GetKey(KeyCode.Space))
    {
        TogglePhysics(true);
    }
}

void TogglePhysics(bool isEnabled)
{
    // IsKinematic needs to be true to disable physics. See the documentation for IsKinematic.
    _rigidbody.IsKinematic = !isEnabled; 
    _rigidBody.detectCollisions = isEnabled;
}

// When respawning, call TogglePhysics(false);