2D Physics change when i build the game

Unity Engine
1

I’m creating a monster truck game where you can use A and D to tilt your truck left and right.

            if (Input.GetAxisRaw("Horizontal") != 0)
            {

                GetComponent<Rigidbody2D>().AddTorque(carRotationSpeed * Input.GetAxisRaw("Horizontal") * -1);

            }

the carRotationSpeed is a public float that i have set to 700
in the editor the rotation speed is fine but when i build the game its much more sluggish, apart from one strange instance where the build version was slightly faster?

i have put this in void Update and void FixedUpdate and the results are the same each time

any reason why this could be happening?

2

Don’t apply physics outside FixedUpdate and don’t gather input outside Update. What’s most likely happening is the performance difference between editor and standalone, and thus the frequency and accuracy of those functions, is why you’re experiencing your issues.

3

I thought so too but not sure where to put the code to solve the problem

4

Instead of code like the above, do yourself a favor and iron it all out, one thing at a time.

  • read the input to a variable
  • do the comparison
  • compute the torque
  • add the torque

Then you can actually display values and reason about what is going on.

You must find a way to get the information you need in order to reason about what the problem is.

What is often happening in these cases is one of the following:

  • the code you think is executing is not actually executing at all
  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also put in Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target.

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

https://discussions.unity.com/t/839300/3