[Solved] Using Mathf.Sin to create a looping Up and down mouvement

Hello

I would like to scroll a 2D object on Y (up and down) for ever.
I thought of Using a Sin.x, with x being the time value (Time.time or Time.deltaTime)

Code (CSharp):

1. BgYPosition = Mathf.Sin (Time.time*upAndDownSpeedMultiplier);
2. Vector3 scrollY = new Vector3 (0f,BgYPosition,0f);
3. transform.position= scrollX + scrollY;;  //scrollX being a simple scroll on X not written here
4.  

the question is, how do I set this up so the Amplitude (y) of my Sin.curve (so the max + min height of my curve) to be independent from the speed of my sin.x (driven by Time.time*Speed I guess, giving the speed it's going up and down)




Thx a lot.

 

You're problem is that when you change the oscillation speed, your 2D object position is jerky.
Is that right?

 

Ok, found it by myself ...
(wich is good

Thx.

 

Thx Eric
no the problem was that I was trying to guess how to change and setup the speed of my "up and down movement" (my phase?) and of my y (amplitude) separetely.

I didi it by writing something like

Code (CSharp):

1.             BgYPosition = 1.75f*Mathf.Sin (Time.time/3) - 2;

were 1.75f is my y, 3 is the speed of my up and down, and -2 is were my middle curve will start on my screen

 

The formula for that is:

y = a*sin(2*pi*f*t )

Where:
a is the amplitute
f is the number of oscillation per second