Weird arithmetic error on some computers only.

[ozone]

//turning
if(Input.GetAxis(“Turning”) > 0){
turnX = turnSensitivity45Time.deltaTime;
}
else if(Input.GetAxis(“Turning”) < 0){
turnX = -turnSensitivity45Time.deltaTime;
}
else{
turnX = 0;
}
transform.rotation *= Quaternion.AngleAxis(turnX, Vector3.up);

The above code is part of a script that handles the player character turning in my game. On some computers, this works perfectly. On others, the program for some reason decides that, even though turnSensitivity and Time.deltaTime are both positive, turnSensitivity45Time.deltaTime = 0. I cannot figure out why, and there seems to be no pattern whatsoever to what machines it occurs on. I tested it on two exactly identical macs and it worked fine on one and not at all on the other. Incidentally, I am using Unity 3.5.3 as a result of some problems that occur when I try to upgrade to Unity 4. Does anyone have any idea what is going on? Please help!

[Statement]

even though turnSensitivity and Time.deltaTime are both positive, turnSensitivity * 45 * Time.deltaTime = 0.

For multiplication to become zero, one of the factors must be zero. In this case either turnSensitivity is zero or Time.deltaTime is zero.

Also, if your Axis is not defined, it will also return zero.

Try debugging it with a simple log output.

Debug.Log("Input.GetAxis(\"Turning\"): " + Input.GetAxis("Turning"));
Debug.Log("turnSensitivity: " + turnSensitivity);
Debug.Log("Time.deltaTime: " + Time.deltaTime);

Time.deltaTime could maybe become zero if Time.timeScale is zero, or if the machine runs without VSync and without a sensible frame rate (deltaTime would be very small and could be rounded down to zero).

[eatsleepindie]

Try changing all of your numerical values to contain the “f” suffix.

//turning
    if(Input.GetAxis("Turning") > 0){
       turnX = turnSensitivity*45f*Time.deltaTime;
    }
    else if(Input.GetAxis("Turning") < 0){
       turnX = -turnSensitivity*45f*Time.deltaTime;
    }
    else{
       turnX = 0f;
    }
    transform.rotation *= Quaternion.AngleAxis(turnX, Vector3.up);