Question Really weird issue with switching states in Unity

Hey Guys!

I'm trying to make my own 2D AI system to move and patrol an npc. Now, I'm using state machines for it and it's not exactly the cleanest code but I think it works. The issue I'm having is, even though I'm returning a new state, that state's execute function does not get triggered. I've sent a video explaining what exactly the issue is, and the scripts.

I have attached a video to explaining what my problem is here as well.

Base State: https://pastebin.com/4JEizAaz (defines the Start, Tick and Exit functions)

EnemyStateMachine: https://pastebin.com/e2QUF1BJ (Runs the Execute() function)

EnemyPatrolState: https://pastebin.com/zc15BeZd

EnemyChaseState: https://pastebin.com/AJtXqB4T

 

Sounds like you wrote a bug!!

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: https://forum.unity.com/threads/how-to-capturing-device-logs-on-ios.529920/ or this answer for Android: https://forum.unity.com/threads/how-to-capturing-device-logs-on-android.528680/

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.

If your problem is with OnCollision-type functions, print the name of what is passed in!

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://forum.unity.com/threads/coroutine-missing-hint-and-error.1103197/#post-7100494

"When in doubt, print it out!(tm)" - Kurt Dekker (and many others)

Note: the

print()

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


ALSO... keep this in mind:

FSM finite state machines:

I suggest never using the term "state machine." Instead, just think:

- I have to keep track of some THING(s)
- That THING might change due to reasons
- Depending on that THING, my code might act differently

That's it. That's all it is. Really!! The classic example is a door:

- track if it is open or closed
- if it is open, you could close it
- if it is closed, you could open it
- if it is open you could walk through it
- if it is closed you could bump into it

Wanna make it more complex? Put a latch on one side of the door.

This is my position on finite state machines (FSMs) and coding with them:

https://forum.unity.com/threads/state-machine-help.1080983/#post-6970016

I'm kind of more of a "get it working first" guy.

Ask yourself, "WHY would I use FSM solution XYZ when I just need a variable and a switch statement?"

All generic FSM solutions I have seen do not actually improve the problem space.

Your mileage may vary.

"I strongly suggest to make it as simple as possible. No classes, no interfaces, no needless OOP." - Zajoman on the Unity3D forums.

 

How do you know? have you put an unqualified debug.log in your "execute" method? (That is, a debug.log that's not in an if statement.)

 

In this situation, it's challenging to trace the cause of the problem just by looking at the code (plus, not all classes were provided, for example, BaseEnemyState). It's better to experiment with a real scenario here to understand which components are on which objects, and so on. In general, having a minimal package with the issue wouldn't hurt; I think it would provide an opportunity to test it personally.