Third Person Camera Controller Doubt. Please Help!

Yo!

So my friend gave me script for my third person game, the script was for the camera. He gave me to go through it and learn something. But now I am stuck on statement and cant figure what is does exactly, he doesn't have time right so I posted my doubt here.

3rd Person Camera Script:

Code (CSharp):

1.  
2. y -= Input.GetAxis("Mouse Y") * ySpeed * 0.02f ;
3.             y = ClampAngle(y, yMinLimit, yMaxLimit);
4.  
5.             yAim = y;

I cant figure out why is he subtracting y (in the first line) with "Input.GetAxis("Mouse Y") * ySpeed * 0.02f". The initial values of y is 0f, ySpeed is 120.

Thanks for your time!

 

Have you tried the script? What happens when you move your mouse up or down?

Does y get reset to 0f at the beginning of that method?

I would guess that the subtraction reverses the camera movement in the up / down direction.

What happens with yAim in the script?

 

"y" is zero in the beginning but in "Start" he set it to 9
I tried removing the "-" sign then it prevents the rotation of camera in x axis
yAim is applied to camera rotation

 

What happens if you replace the '-' with a '+'?

y is zero in the beginning of what?

Again, what happens with yAim in the script?