Mousewheel unity code example
Example 1: unity mouse wheel
Input.mouseScrollDelta.y //Return 1 when up and -1 when down and 0 when the mouse scroll is not rotated
Example 2: unity on mousewheel down
if (Input.GetAxis("Mouse ScrollWheel") > 0f) // forward
{
}
if (Input.GetAxis("Mouse ScrollWheel") < 0f) // backwards
{
}