FixedUpdate and Time.deltaTime slowe

Questions & Answers
1

I am moving rigidbodies around with velocity.

Is simply using

function FixedUpdate(){


thisRigidbody.velocity.x = movement.x;

}

enough to make the movement framerate INDEPENDENT. versus

function FixedUpdate(){


thisRigidbody.velocity.x = movement.x * Time.deltaTime;


}

Which seems to slowdown my game.

Thanks in advance!

3

It is slower with Time.deltaTime because this value is always lesser than 1.

In fact it does not make sense to set the velocity using Time.deltaTime since a velocity is already integrating the time. You need to use this value when you set a position using a value that is a velocity. This is basic middle school physics:

velocity is a value which unit is in m/s

time is a value which unit is in s

position is a value which unit is in meters (m)

Therefore:

position = velocity * time (m = m/s * s)

It would make sense if movement was an acceleration vector, but I don’t think that it is the case here.

2

The FixedUpdate already is framerate-independent.
I suggest you try to learn the exact difference between Update() and FixedUpdate ().
They correspond to Time.deltaTime and Time.fixedDeltaTime.

EDIT: like Kryptos pointed out, the Time.deltaTime inside a FixedUpate indeed does return the fixed timestep as mentioned in the documentation. I wasn’t aware of that.