Category: Unity
Home / Code /
Your consent is required to display this content from youtube - Privacy Settings
June 21, 2015

Random Spawning With Culling

In my 1GAM space shooter, I spawn a bunch of enemy ships around the level at the start of the game and then hide them until the player gets within a certain distance. The main reason for hiding objects after spawning is because it conserves draw calls. This script is part of my Impulse Framework.

ObjectSpawner.cs

ObjectSpawnerEditor.cs

As with all Editor scripts, this must be in a folder called “Editor”.

How To Use

Setup is very simple. I recommend creating a blank game object called Spawner and attaching the script.

  • Specify the objects you want to randomly spawn in the ObjectSpawnPrefabs array. Note that they don’t have to be prefabs.
  • Number To Spawn is the number of objects you want to randomly spawn.
  • Min Distance Between Spawned Objects is the minimum world space units between each spawned object.
  • Culling Target is the object culling distance will be compared against. For example, if you want to hide objects until the player gets within a certain distance of them, set the player object as the culling target.
  • Hide Object Spawned Distance is the distance at which culling will occur.
  • Update Interval is how often (in seconds) the culling will happen. A lower rate increases performance impact.

Lastly, you’ll notice a Box Collider is added to the object you attach this script to. The size of the Box Collider is the spawn area.

CullObject.cs

Actual object culling is handled by CullObject.cs, which checks if the culling target is within the Sphere Collider’s bounds. When ObjectSpawner spawns an object, it creates a child object called “Culling Sphere” with a sphere collider and the CullObject script attached. When the culling target is not within the bounds of the Culling Sphere’s sphere collider, the spawned object is culled (hidden).

May 31, 2015

1GAM Space Shooter – Firing Bullets While Preserving Momentum

Adding ship firing was supposed to be easy: Just instantiate a bullet prefab at the location of the gun, set the direction to match the gun’s rotation, and then apply a force. But something was bothering me – the bullet looked like it was flying off at an angle every time. It turns out if your camera is set up to follow an object, anything that moves in a straight direction from that object will appear to fly off at an angle as long as the object is moving.

The solution? Add the moving object (gun) momentum to the bullet.

The Setup

I have a ship object with several child objects. One of these is the spaceship sprite, and another is an empty game object whose transform is positioned on the ship’s gun.

1GAM Space Shooter Ship Setup

The bullet spawn location is placed in front of the single gun sprite so bullets do not spawn on the ship itself.

Attached to the PlayerShip parent object is a FireProjectile class, which is attached to every object in the game that could fire a projectile:

using UnityEngine;
using System.Collections;
 
public class FireProjectile : MonoBehaviour
{
    // Where the projectile should spawn from.
    [SerializeField]
    Transform gunMount;
    // The projectile prefab.
    [SerializeField]
    Rigidbody2D projectile;
    // The parent transform for the projectiles.
    [SerializeField]
    Transform ProjectilesParent;
 
    [SerializeField]
    bool debugRay = false;
 
    public void Fire(float speed , Vector3 direction)
    {
        Rigidbody2D shot;
        shot = (Rigidbody2D)Instantiate(projectile, gunMount.position, gunMount.rotation);
        shot.AddForce((gunMount.up + direction) * speed);
 
        // Set shot parent
        if (ProjectilesParent != null)
            shot.transform.parent = ProjectilesParent;
 
        // Debug raycasting
        if (debugRay)
            Debug.DrawRay(transform.position, (gunMount.up + direction) * speed, Color.red, 5.0f);
    }
}

Each object that fires bullets has its own ProjectilesParent object:

1GAM space shooter projectilesparent

Right now, only the player ship fires bullets.

Each object that is a ProjectilesParent has a FollowTarget script that forces the parent object to match the target’s transform position, which makes the bullet appear to fly in a straight line instead of at an angle due to the camera being centered on an object that is moving.

The FollowTarget script:

using UnityEngine;
using System.Collections;

// Follows target position
public class FollowTarget : MonoBehaviour {
    // Control parameters
    [SerializeField]
    Transform target;

    // Executed each physics simulation frame
    void FixedUpdate () {
        transform.position = target.position;
    }
}

In a nutshell, here is what is happening:

  • Projectiles are being instantiated like normal.
  • Projectiles, upon instantiation, are parented to an empty game object.
  • The empty game object’s transform is set to match the ship’s transform every FixedUpdate(), which causes projectiles to match the ship’s momentum instead of ignoring it.

As you may have noticed, this is not ideal for all weapons – only for those that need to also have the firing object’s momentum, which generally includes all projectiles.

The Result

May 26, 2015

One Game A Month Challenge – Procedural 2D Space Shooter

Back when I used Construct 2, I created a 2D space shooter with wave-based enemies and random asteroids that would damage both enemies and players.

Recently I heard about the One Game A Month challenge and decided to try it. This post defines the goals of my 2D space shooter, which I call Project Icarus.

Influences

The main influence for this game is S.P.A.Z – Space Pirates and Zombies. One thing Icarus – Wave Attack (the Construct 2 space shooter) did not have is mouse controls, which is better defined as physics-based movement with mouse input. Given how much I liked the feel of the player ship in SPAZ, I’ve decided to make the change from tight ‘snappy’ controls to more fluid momentum-based motion.

Project Icarus

Keeping in mind that I have one month – better defined as 30 days – to do this, I will separate the ‘core’ from the ‘extras’ so I don’t feel bad if I don’t get around to the latter.

Core

  • Physics-based mouse input controls for the player ship. [Mostly done!]
  • Player ship firing and taking damage.
  • Player ship shields automatically activating when an hazardous object gets within range.
  • Infinite starfield background. [Already done!]
  • Procedurally generated nebulae with random placement. [Already done!]
  • Randomly placed enemies within a set distance from the player’s initial spawn.
  • Randomly placed asteroids within a set distance from the player’s initial spawn and enemies. This means asteroids need to be spawned after enemies.
  • Basic enemy AI that fires at the closest hostile target (either the player or asteroid), and will seek out the player ship if it is within a certain distance.
  • Asteroids break into smaller parts when shot or colliding with another object. The game needs to have objects bounce off each other after collision (except bullets).
  • Smaller asteroids get destroyed upon collision.

Extras

  • Missiles! Only homing missiles will do, since missiles that travel directly to target are unfun. If the core gets done, this asset should speed up this extra.
  • Decoys. If we add missiles, then decoys naturally follow.
  • Powerups. Icarus – Wave Attack had the ship automatically upgrade upon collecting debris, and it would be cool to bring this back.

Current Progress

February 25, 2015

Unity Sound Manager (C#)

The Sound Manager is used for loading and playing all sounds in a scene. Unlike the Music Manager, the Sound Manager is not persistent across scenes because each scene likely has different audio clips to play.

BaseSoundManager.cs

using UnityEngine;
using System.Collections;

public class SoundObject {
    public AudioSource source;
    public GameObject sourceGO;
    public Transform sourceTR;
    
    public AudioClip clip;
    public string name;
            
    public SoundObject (AudioClip aClip, string aName, float aVolume) {
        // in this (the constructor) we create a new audio source and store the details of the sound itself
        sourceGO = new GameObject("AudioSource_"+aName);
        sourceTR = sourceGO.transform;
        source = sourceGO.AddComponent<AudioSource>();
        source.name = "AudioSource_"+aName;
        source.playOnAwake = false;
        source.clip = aClip;
        source.volume = aVolume;
        clip = aClip;
        name = aName;
    }
    
    public void PlaySound (Vector3 atPosition) {
        sourceTR.position = atPosition;
        source.PlayOneShot(clip);
    }
}

public class BaseSoundManager : MonoBehaviour {
    public static BaseSoundManager Instance;
    
    public AudioClip[] GameSounds;
    
    private int totalSounds;
    private ArrayList soundObjectList;
    private SoundObject tempSoundObj;
    
    public float volume = 1;
    public string gamePrefsName = "DefaultGame"; // DO NOT FORGET TO SET THIS IN THE EDITOR!!

    public void Awake() {
        Instance = this;
    }
    
    void Start () {
        // we will grab the volume from PlayerPrefs when this script first starts
        volume = PlayerPrefs.GetFloat(gamePrefsName+"_SFXVol");
        Debug.Log ("BaseSoundController gets volume from prefs "+gamePrefsName+"_SFXVol at "+volume);
        soundObjectList = new ArrayList();
        
        // make sound objects for all of the sounds in GameSounds array
        foreach (AudioClip theSound in GameSounds) {
            tempSoundObj = new SoundObject(theSound, theSound.name, volume);
            soundObjectList.Add(tempSoundObj);
            totalSounds++;
        }
    }
    
    public void PlaySoundByIndex(int anIndexNumber, Vector3 aPosition) {
        // make sure we're not trying to play a sound indexed higher than exists in the array
        if (anIndexNumber>soundObjectList.Count) {
            Debug.LogWarning ("BaseSoundController>Trying to do PlaySoundByIndex with invalid index number. Playing last sound in array, instead.");
            anIndexNumber = soundObjectList.Count-1;
        }
        
        tempSoundObj = (SoundObject)soundObjectList[anIndexNumber];
        tempSoundObj.PlaySound(aPosition);    
    }

}

Usage

Each scene with audio requirements (excluding background music, which is handled by the Music Manager) should have a Sound Manager object with either the BaseSoundManager or an extended script attached. The Sound Manager is a singleton, but it is not persistent from scene to scene due to different audio requirements. If multiple scenes have the same audio requirements, simply add a DontDestroyOnLoad() call to the Start() function.

The Sound Manager takes an array of audio clips that the scene will require. It also takes in a playerprefs string. These must be set in the inspector.

Each audio clip in the array will have its own AudioSource and GameObject instantiated when the Sound Manager first runs. Each sound has its own audio channel in order to avoid overlaps or too many different sounds playing on a single AudioSource. An internal class called SoundObject is used to store information about each audio source and its associated game object.

 

February 23, 2015

Unity MusicManager and Music Playlist (C#)

The Music Manager is intended for playing music. Many games have background music that plays independently of sounds. Some games may want music to persist from scene to scene or stop and then restart where it left off. The Music Manager is a singleton persistent game object intended to ease in the production of this.

MusicManager.cs

http://pastebin.com/cB89jPtD

Usage

MusicManager.cs should be added to an empty game object in the splash scene, this way it persists from scene to scene.

The Music Manager is capable of automatically fading in music when it loads, making for nicer transitions into a scene. The Fade Duration can be set in the inspector.

The Music Manager is best used with Music Playlists. A Music Playlist is an empty game object with the MusicPlaylist.cs script attached. MusicPlaylist.cs takes an array of audio clips. I recommend leaving the ‘Play On Awake’ option checked, this way the Music Manager will begin playing the playlist as soon as the scene is loaded. Each playlist should be set in the first scene in which the playlist is to be played.

The Music Manager automatically keeps playing the current playlist when the scene changes, unless the new scene has a playlist object. When a new playlist object is encountered, all other playlist objects are destroyed and the Music Manager loads the new playlist and begins playing it, possibly with a fade-out and fade-in if the Fade Duration is set in the Music Manager.

It is assumed each scene requiring a new playlist will have only one MusicPlaylist object. As of this post, there is no error handling if a scene has multiple playlist objects in the hierarchy.

I highly recommend watching the YouTube overview to understand how the music manager and music playlist systems work.

YouTube Overview and Demonstration

Next Up: Sound Manager

The sound manager is in charge of playing sound clips such as explosions, projectiles, etc. It is independent of the Music Manager so that sound effects can be controlled separately from background music. Read about the Sound Manager here: https://www.zesix.com/2015/02/unity-soundmanager-c/

February 18, 2015

Unity Mouse_Input (C#)

This is a basic mouse input class to be customized for a particular game’s needs and loaded depending on device. Note that unlike the Keyboard_Input class, this requires tweaking the Input Manager in the project settings since the default are not fully compatible with this (in my opinion) more optimized script.

Mouse_Input.cs

using UnityEngine;
using System.Collections;

public class Mouse_Input : BaseInputController {
    private Vector2 prevMousePos;
    private Vector2 mouseDelta;
    
    private float speedX = 0.05f;
    private float speedY = 0.1f;
    
    public void Start () {
        prevMousePos= Input.mousePosition;
    }
    
    public override void CheckInput () {
        // get input data from vertical and horizontal axis and store them internally in vert and horz so we don't
        // have to access them every time we need to relay input data out
        
        // calculate a percentage amount to use per pixel
        float scalerX = 100f / Screen.width;
        float scalerY = 100f / Screen.height;
        
        // calculate and use deltas
        float mouseDeltaY =  Input.mousePosition.y - prevMousePos.y;
        float mouseDeltaX =  Input.mousePosition.x - prevMousePos.x;
        
        // scale based on screen size
        vert += ( mouseDeltaY * speedY ) * scalerY;
        horz += ( mouseDeltaX * speedX ) * scalerX;
        
        // store this mouse position for the next time we're here
        prevMousePos= Input.mousePosition;
        
        // set up some boolean values for up, down, left and right
        Up    = ( vert>0 );
        Down    = ( vert<0 );
        Left    = ( horz<0 );
        Right    = ( horz>0 );    
        
        // get fire / action buttons
        Fire1= Input.GetButton( "Fire1" );
    }
    
    public void LateUpdate() {
        // check inputs each LateUpdate() ready for the next tick
        CheckInput();
    }
}

Next Up: MusicManager.cs

Many games have background music. The Music Manager is a singleton in charge of making sure music loads and is played when needed.

Links
Recent Posts
Follow Me

Privacy Settings
We use cookies to enhance your experience while using our website. If you are using our Services via a browser you can restrict, block or remove cookies through your web browser settings. We also use content and scripts from third parties that may use tracking technologies. You can selectively provide your consent below to allow such third party embeds. For complete information about the cookies we use, data we collect and how we process them, please check our Privacy Policy
Youtube
Consent to display content from - Youtube
Vimeo
Consent to display content from - Vimeo
Google Maps
Consent to display content from - Google
Save