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Resolved Enemy Shoots Player 2D

Discussion in 'Scripting' started by T05619, May 11, 2022.

  1. T05619

    T05619

    Joined:
    Apr 19, 2022
    Posts:
    5
    Im trying to make a 2D game (side on like mario) and im struggling to find a way for the enemy to shoot at the player. So i want the bullet to be spawned/created from a point and move towards the player then a cooldown then the enemy shoots again. Im completely lost at what to do and where to start.
     
  2. Omniglitch

    Omniglitch

    Joined:
    May 29, 2017
    Posts:
    37
    There are several scripts you'll need to write to implement a combat system. I'll get you started on two of the scripts, one for the enemy and one for the projectile they fire. I'm only providing the code specific to your question, but you'll also need to add in code for handling collisions and for destroying the projectile when it collides or goes out of bounds.

    Code (CSharp):
    1. using System.Collections;
    2. using System.Collections.Generic;
    3. using UnityEngine;
    4.  
    5. public class EnemyController : MonoBehaviour
    6. {
    7.     public GameObject projectilePrefab;
    8.     public Transform barrelEnd;
    9.     public Transform player;
    10.     public float cooldown = 1f;
    11.     private float lastShotFired;
    12.  
    13.     void Start()
    14.     {
    15.         lastShotFired = Time.time;          
    16.     }
    17.  
    18.     void Update()
    19.     {
    20.         MoveEnemy();
    21.      
    22.         float timeSinceLastShotFired = Time.time - lastShotFired;
    23.         if ( timeSinceLastShotFired >= cooldown ) {
    24.             lastShotFired = Time.time;
    25.             Shoot();
    26.         }
    27.     }
    28.  
    29.     void MoveEnemy()
    30.     {
    31.         // Handle movement logic here
    32.     }
    33.  
    34.     void Shoot()
    35.     {
    36.         Vector3 movementVector = Transform.position - player.position;
    37.         GameObject projectile = Instantiate( projectilePrefab, barrelEnd.position, Quaternion.LookRotation( movementVector, Vector3.forward ) );
    38.         projectile.GetComponent<ProjectileController>().Init( movementVector );
    39.     }
    40. }
    Code (CSharp):
    1. using System.Collections;
    2. using System.Collections.Generic;
    3. using UnityEngine;
    4.  
    5. public class ProjectileController : MonoBehaviour
    6. {
    7.     public float speed = 1f;
    8.     private Vector3 movementVector;
    9.  
    10.     public void Init( Vector3 vec )
    11.     {
    12.         movementVector = vec.Normalize;
    13.     }
    14.  
    15.     void Update()
    16.     {
    17.         Transform.position += movementVector * speed * Time.deltaTime;
    18.     }
    19. }
    Not sure how well this will mesh with your code if you're using 2D functions. The closest I've come to making a 2D game is using an orthographic camera on a 3D world. Also not sure if the Quaternion.LookRotation will work for you; it all depends on which axis your camera is facing.

    Also note that using Instantiate and Destroy for things like projectiles is a really bad practice since it creates a ton of garbage. You'll want to look into Object Pooling at some point.
     
    T05619 likes this.
  3. Kurt-Dekker

    Kurt-Dekker

    Joined:
    Mar 16, 2013
    Posts:
    38,517
    Google would be the best place to start. Just type in your question along with the word Unity and work through the first three or four tutorials, or stop when you understand it.

    Tutorials and example code are great, but keep this in mind to maximize your success and minimize your frustration:

    How to do tutorials properly, two (2) simple steps to success:

    Step 1. Follow the tutorial and do every single step of the tutorial 100% precisely the way it is shown. Even the slightest deviation (even a single character!) generally ends in disaster. That's how software engineering works. Every step must be taken, every single letter must be spelled, capitalized, punctuated and spaced (or not spaced) properly, literally NOTHING can be omitted or skipped.

    Fortunately this is the easiest part to get right: Be a robot. Don't make any mistakes.
    BE PERFECT IN EVERYTHING YOU DO HERE!!


    If you get any errors, learn how to read the error code and fix your error. Google is your friend here. Do NOT continue until you fix your error. Your error will probably be somewhere near the parenthesis numbers (line and character position) in the file. It is almost CERTAINLY your typo causing the error, so look again and fix it.

    Step 2. Go back and work through every part of the tutorial again, and this time explain it to your doggie. See how I am doing that in my avatar picture? If you have no dog, explain it to your house plant. If you are unable to explain any part of it, STOP. DO NOT PROCEED. Now go learn how that part works. Read the documentation on the functions involved. Go back to the tutorial and try to figure out WHY they did that. This is the part that takes a LOT of time when you are new. It might take days or weeks to work through a single 5-minute tutorial. Stick with it. You will learn.

    Step 2 is the part everybody seems to miss. Without Step 2 you are simply a code-typing monkey and outside of the specific tutorial you did, you will be completely lost. If you want to learn, you MUST do Step 2.

    Of course, all this presupposes no errors in the tutorial. For certain tutorial makers (like Unity, Brackeys, Imphenzia, Sebastian Lague) this is usually the case. For some other less-well-known content creators, this is less true. Read the comments on the video: did anyone have issues like you did? If there's an error, you will NEVER be the first guy to find it.

    Beyond that, Step 3, 4, 5 and 6 become easy because you already understand!

    Finally, when you have errors...

    Remember: NOBODY here memorizes error codes. That's not a thing. The error code is absolutely the least useful part of the error. It serves no purpose at all. Forget the error code. Put it out of your mind.

    The complete error message contains everything you need to know to fix the error yourself.

    The important parts of the error message are:

    - the description of the error itself (google this; you are NEVER the first one!)
    - the file it occurred in (critical!)
    - the line number and character position (the two numbers in parentheses)
    - also possibly useful is the stack trace (all the lines of text in the lower console window)

    Always start with the FIRST error in the console window, as sometimes that error causes or compounds some or all of the subsequent errors. Often the error will be immediately prior to the indicated line, so make sure to check there as well.

    All of that information is in the actual error message and you must pay attention to it. Learn how to identify it instantly so you don't have to stop your progress and fiddle around with the forum.
     
    T05619 likes this.
  4. T05619

    T05619

    Joined:
    Apr 19, 2022
    Posts:
    5
    Thanks so much Omniglitch this helped so much :) and thanks Kurt-Dekker i did in fact search it up and tell my cactus how it worked :)
     
    Last edited: May 12, 2022