Can't change camera FOV during playmode

[sd_trent]

I noticed that a script that I have that changes the main cameras FOV isn’t working anymore, whereas it was working a few months ago. I haven’t updated to any major new Unity versions (I’m running 2021.3.27f1) and I’m not using Cinamachine or VR.

Here is the function in question.

private void updateFOV()
    {
        float hFOVrad = fieldOfView * Mathf.Deg2Rad;
        float camH = Mathf.Tan(hFOVrad * 0.5f) / cam.aspect;
        float vFOVrad = Mathf.Atan(camH) * 2;
        cam.fieldOfView = vFOVrad * Mathf.Rad2Deg;
    }

The FOV can only be changed in edit mode, and when the play button is pressed the changes stay. What’s really odd though is if I selected the “physical camera” option, then my script works again suddenly.

Any tips would be greatly appreciated!

[Kurt-Dekker]

My first guess is that something else is controlling camera FOV, such as another script or even another animation.

Animations can be sneaky like this because of the (X) Write Defaults option in Animator states. You would probably want that tickbox OFF if you animate anything that shares the same hierarchy as the camera.

At runtime, try destroying any animator / animation going on and see if you can now control FOV.

Otherwise… Time to start debugging! Here is how you can begin your exciting new debugging adventures:

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

Once you understand what the problem is, you may begin to reason about a solution to the problem.

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
• you’re getting an error or warning and you haven’t noticed it in the console window

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 names of the GameObjects or Components involved?
• 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 supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as Debug.Log("Problem!",this);

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

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

Visit Google for how to see console output from builds. If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer for iOS: How To - Capturing Device Logs on iOS or this answer for Android: How To - Capturing Device Logs on Android

If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

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:

Coroutine missing hint and error

This is so unnecessary. Use the beauty and power of instantly and immediately putting a Debug.Log() statement into the very start of the coroutine, right at the top. Do this always at the very first sign of trouble or question in your mind. The instant you did this you would see “Oh man, this code is simply not getting run!” And you could LASER-FOCUS 100% your efforts on studying what you expect to run it, eg., the call location, and isolate why it is not running. You would look at literall…

“When in doubt, print it out!™” - Kurt Dekker (and many others)

Note: the print() function is an alias for Debug.Log() provided by the MonoBehaviour class.

[sd_trent]

@Kurt-Dekker

Animations can be sneaky like this because of the (X) Write Defaults option in Animator states. You would probably want that tickbox OFF if you animate anything that shares the same hierarchy as the camera.

Thank you! This was the problem, I have an animator component in a parent object. I just disabled the animator in script and now everything is working again.