Question Top Down Shooter 2D - Help With Aiming Script

Hello, I'm making a top down shooter game and I'm having some trouble with getting the character to aim the right way. It starts out fine, but as the game goes on and the player collides with walls and enemies, the players rotation becomes desynced with the position of the cursor. Here's the code I have written:

Code (CSharp):

1. //just the aiming
2. private void Update()
3.     {
4.         mousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
5.         Vector2 aimDirection = mousePosition - rb.position;
6.         float aimAngle = Mathf.Atan2(aimDirection.y, aimDirection.x) * Mathf.Rad2Deg - 90f;
7.         rb.rotation = aimAngle;
8.     }

If anyone has any insight or tips it would be greatly appreciated, thank you!
I have also attached a photo, the red circle is where my cursor was when I took the screenshot.

 

Any rotation property in Unity accepts quaternions, not floats.

I'm sure this line can't work at all // Edit: I forgot about RigidBody2D

Code (csharp):

1. rb.rotation = aimAngle;

Instead you're supposed to supply a rotation in Euler angles

Code (csharp):

1. float aimAngle = Mathf.Atan2(aimDirection.y, aimDirection.x);
2. rb.rotation = Quaternion.Euler(0f, 0f, aimAngle);

Edit: Scratch that, it's not because of this. See next post.

 

"Akshually..."

It will work if

rb

is a Rigidbody2D.

https://docs.unity3d.com/ScriptReference/Rigidbody2D-rotation.html

OP, not sure what's going on... is some other Rigidbody2D in your scene or hierarchy rotating perhaps??

It sure sounds like it is ...

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 or 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.

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.

 

Whoops I forgot about 2D physics being different

 

the enemies rotate toward the player yes, but the rotation de-sync still happens on colliding with a wall, which doesn't rotate

 

Collisions can impart torque to a Rigidbody, making it turn.

Find out exactly what object(s) is turning / twisting and either constrain it (in the Rigidbody) to not do that, or otherwise drive its rotation to what you want it to be.

 

locking the Z rotation on the rigid body worked. thanks!