convert multiplication from FixedUpdated to Update

Hi guys
Sorry if thie question is silly.

I would like to convert this old script using Update() instead of FixedUpdate(), but i can't figure how to do.

This is my old script:

FixedUpdate(){
x = x * y;
}

So during 1 second, with a framerate of 10 frame per seconds, that do something like that, isn't it?:
x = x * y * y * y * y * y * y * y * y * y * y;
or
x = x * Mathf.Pow(y, 10);


So i tried something like that but it's look not good.

Update(){
frameRate = 10; // this the old frame Rate for the FixedUpdate

x = x * Mathf.Pow(y, frameRate * Time.deltaTime);
}

someone can help me?

Thanks

 

I don't understand, you want to change update so that it runs on a fixed frameRate, is that right?
you just need Time.deltaTime*frameRate for that.

lets say Time.deltaTime returns 0.25. so you would have 10*0.25, or 10/4 so you do x *= Mathf.Pow(y, 2.5);

what i think you want is:
x *= y*frameRate*Time.deltaTime;

 

Hi Jister

I want to use this code:

FixedUpdated(){
x = x * y;
}

In a "Updated" function, instead of a "FixedUpdated". My goal is to get my script time independent.

I tried your solution:
I set the fixed time step to 0.16666666 to have a frame rate of 60fps inside an FixedUpdated function.
And i compared your solution (inside a "Updated" function):

Updated(){
frameRate = 60;
x *= y*frameRate*Time.deltaTime;
}

and my old script (inside an "FixedUpdated" function):

FixedUpdated(){
x = x * y;
}

That's work fine, but when i change the fixed time step to 0.0333333 to have a framerate of 30 fps, and i change to the variable "framerate" to 30 in the script. That doesn't works anymore.
I can't figure out what i do wrong.

 

how are your setting the fixed rate for FixedUpdate()?

 

in edit/project Settings/Time, i change the value "fixed timestep" with 1/framerate.
I want a framerate of 30fps so i put 0.03333333.

 

what are the x and y values and what result do you get from x*=y in fixedupdate?
i try to mimic what you do but don't know what you're looking for.

 

it was to move a character.
x was the character's speed at the last frame, and so at each frame in fixedUpdated i multiply the speed by 0.9 to keep inertia in the character. So it was something like that:
newSpeed = oldSpeed * inertiaFactor;
it was simple to do it with a fixed framerate, but now i need it in a update() function

 

sorry you should use fixedDeltaTime instead of deltaTime, my mistake ;-)

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class Example : MonoBehaviour
5. {
6.     public float fixedFrameRate;
7.     public float x;
8.     public float y;
9.     public float xfix;
10.     public float yfix;
11.  
12.     void Update()
13.     {
14.         x *=y*Time.fixedDeltaTime*fixedFrameRate;
15.     }
16.     void FixedUpdate()
17.     {
18.         xfix *=yfix;
19.     }
20.  
21.  
22. }
23.  

 

For now that's doesn't work.

I don't understand this last script:

x *=y*Time.fixedDeltaTime*fixedFrameRate;

it's look like this code isn't time independent, what happen if the update function is call two time by frame, or one time every 2 frames?

 

delta time is the time since the last frame, so if you have 1 frame a second deltatime is going to be 1, if you have 2 frames a second deltatime is 0.5, 100 frames a second 0.01

If you want to move 10 units/s you just need 10*Time.deltaTime

 

if you put this script on an object in the scene, set your fixed timeStep to lets say 0.02 and framerate to 50, 1 for x and 0.9 for y. You'll see both x end up the same value...
isn't that what you wanted? update and fixedupdate giving the same outcome?