Time.deltaTime really slow

Questions & Answers
1

I have been using addforce with my rigidbody but realised that on slower computers, you won’t get the same force. I then tried to impliment Time.deltaTime with my addforce script but the rigidbody then started moving really really slow in the game and had terrible acceleration. I don’t know what to do. Here is my script:

var maxVelocity : float = 5;
function FixedUpdate () {

	if (Input.GetKey ("down")) 
		{
			 rigidbody.AddForce (Vector3.forward * -0.2 *

Time.deltaTime);
}

			if (Input.GetKey ("up")) 
		{
			 rigidbody.AddForce (Vector3.forward * 0.2 *

Time.deltaTime);
}

					if (Input.GetKey ("left")) 
		{
			 rigidbody.AddForce (Vector3.left * 0.2 * Time.deltaTime);
		}
		
		
		
					if (Input.GetKey ("right")) 
		{
			 rigidbody.AddForce (Vector3.right * 0.2 *

Time.deltaTime);
}

		    var velocity = rigidbody.velocity;
    if (velocity == Vector3.zero) return;

    var magnitude = velocity.magnitude;
    if (magnitude > maxVelocity)
    {
        velocity *= (maxVelocity / magnitude);
        rigidbody.velocity = velocity;
    }
		
}
3

The reason it seems to be really slow, is that when you changed to using Time.deltaTime, you forgot to multiply all your values by your expected framerate!

To elaborate- if you don’t use Time.deltaTime, it adds a given force every single frame. When you multiply by Time.deltaTime, it normalises everything such that it instead adds the amount of force per frame that it would add up to that amount over a single second. So, under normal cirumstances, you would have to multiply all your other values by about 60 (assuming 60 frames per second was what you were getting in the first place) to replicate the original behaviour.

2

Have you made sure that maxVelocity = 5 isn’t too low for your game? Try setting it to 500 and see if that makes a difference.