physics randomness problem

Questions & Answers
1

Hello i have a problem. When i press W the object jumps up but each time with a different height. I tried to do it through fixedupdate, but then he either jumps every time with a different height or does not jump at all.

 void Update()
        {
            Jump();
        }
    
    private void Jump()
        {
            if (Input.GetKeyDown(KeyCode.W))
            {
                
                var jumpVel = new Vector2(0, jumpForce * Time.deltaTime);
                rb.velocity += jumpVel;
                
            }
        }
3

You’re basically scaling your jumping force erratically.

Constant forces/motions (i.e. velocity) never need to be scaled by the framerate. That’s what you do when you’re making that change yourself.

// When you first change this, expect it to be ~60+ times
// stronger than you intend, depending on your average framerate
Vector2 jumpVel = new Vector2(0, jumpForce);
2

Something like this should do it.

private bool bJumping = false;
void FixedUpdate()
{
    if (Input.GetKey(KeyCode.W) && !bJumping)
    {
        bJumping = true;
        Jump();
    } else bJumping = false; //now jumping is possible again
    //issue: you need to keep it true until you land (or jumping in the air is possible)
}
     
private void Jump()
{
    var jumpVel = new Vector2(0, jumpForce * Time.fixedDeltaTime);
    rb.velocity += jumpVel;
}