I’m making an FPS in unity and I made a script to throw a grenade, it works, but when I had tested it a few times, the scripts stops working, and the same with a hook script, I made a graple hook script with raycast and the raycast only hits to the objects aligned horizontally with the camera, it doesn’t matter if I rotate the camera, but then I deleted the script and I linked another time the script to the player and it works, I don’t know why sometimes works and sometimes not.
Whenever you need more information about what your program is doing as well as how and where it is deviating from your expectations, that means it is…
Time to start debugging!
By debugging you can find out exactly what your program is doing so you can fix it.
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.
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:
If you are looking for how to attach an actual debugger to Unity: Unity - Manual: Debugging C# code in Unity
“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.
If you learn more by debugging and there is some specific thing that still seems mysterious…
How to report your problem productively in the Unity3D forums:
This is the bare minimum of information to report:
- what you want
- what you tried
- what you expected to happen
- what actually happened, log output, variable values, and especially any errors you see
- links to actual Unity3D documentation you used to cross-check your work (CRITICAL!!!)
The purpose of YOU providing links is to make our job easier, while simultaneously showing us that you actually put effort into the process. If you haven’t put effort into finding the documentation, why should we bother putting effort into replying?
If you post a code snippet, ALWAYS USE CODE TAGS:
How to use code tags: Using code tags properly
- Do not TALK about code without posting it.
- Do NOT post unformatted code.
- Do NOT retype code. Use copy/paste properly using code tags.
- Do NOT post screenshots of code.
- Do NOT post photographs of code.
- Do NOT attach entire scripts to your post.
- ONLY post the relevant code, and then refer to it in your discussion.
We won’t be able to tell you anything with that amount of information. Like @Kurt-Dekker mentioned you need to start adding debugging info to the script to see what’s actually happening. In fact I recommend adding them as you write new scripts just because it’s always valuable to be able to look at the console and see what is happening.
Okay,thanks a lot, I will try to debug and try to find the error.