GroundCheck Issue C#

Question

I have followed a YouTube tutorial but the code to ground check (So the player cannot jump in the air leading to flying) is not working. The code is:

[SerializeField] private bool isCharacterGrounded = false;
 private Vector3 velocity = Vector3.zero;

private void Update()
{
  HandleIsGrounded();
  HandleGravity();
  HandleJumping();
}

private void HandleIsGrounded()
{
    isCharacterGrounded = Physics.CheckSphere(transform.position, groundDistance);
}

private void HandleGravity()
{
    if (isCharacterGrounded && velocity.y < 0)
    {
        velocity.y = -2f;
    }

    velocity.y += gravity * Time.deltaTime;
    controller.Move(velocity * Time.deltaTime);
}

private void HandleJumping()
{
    if (Input.GetKeyDown(KeyCode.Space) && isCharacterGrounded)
    {
        velocity.y += Mathf.Sqrt(jumpForce * -2f * gravity);
    }
}

Answer 1

To do a ground check, either with a CheckSphere or a Raycast, you need a Layer Mask to identify what "layer" you want to check for. Otherwise your ground check will always return true because it will be hitting your player's own collider.

[SerializeField] private bool isCharacterGrounded = false;

// Assign in the inspector
public LayerMask GroundLayer; 
private Vector3 velocity = Vector3.zero;

private void Update()
{
  HandleIsGrounded();
  HandleGravity();
  HandleJumping();
}

private void HandleIsGrounded()
{
        isCharacterGrounded = Physics.CheckSphere(transform.position, groundDistance, GroundLayer);
}    
   

Next, make sure that your ground is assigned to the Ground layer in the inspector

And last, assign the Ground layer to the GroundLayer variable in the inspector