Help make Machine Gun damage enemies and not player

Question

I'm working on a 2.5d side scrolling shooter and I have a script on my machine gun to make it aim towards the mouse. Unfortunately if the player is silly he can shoot himself which is bad. How can I make it so the script does not send a damage message to the player but still sends it to the enemies (who have damage receiving scripts). Thank you so much!

var range = 100.0; var fireRate = 0.05; var force = 10.0; var damage = 5.0; var bulletsPerClip = 40; var clips = 20; var reloadTime = 0.5; private var hitParticles : ParticleEmitter; var muzzleFlash : Renderer;

private var bulletsLeft : int = 0; private var nextFireTime = 0.0; private var m_LastFrameShot = -1;

function Start () { hitParticles = GetComponentInChildren(ParticleEmitter);

 // We don't want to emit particles all the time, only when we hit something.
 if (hitParticles)
     hitParticles.emit = false;
 bulletsLeft = bulletsPerClip;

function LateUpdate() { if (muzzleFlash) { // We shot this frame, enable the muzzle flash if (m_LastFrameShot == Time.frameCount) { muzzleFlash.transform.localRotation = Quaternion.AngleAxis(Random.value * 360, Vector3.forward); muzzleFlash.enabled = true;

         if (audio) {
             if (!audio.isPlaying)
                 audio.Play();
             audio.loop = true;
         }
     } else {
     // We didn't, disable the muzzle flash
         muzzleFlash.enabled = false;
         enabled = false;

         // Play sound
         if (audio)
         {
             audio.loop = false;
         }
     }
 }

function Fire () { if (bulletsLeft == 0) return;

 // If there is more than one bullet between the last and this frame
 // Reset the nextFireTime
 if (Time.time - fireRate &gt; nextFireTime)
     nextFireTime = Time.time - Time.deltaTime;

 // Keep firing until we used up the fire time
 while( nextFireTime &lt; Time.time &amp;&amp; bulletsLeft != 0) {
     FireOneShot();
     nextFireTime += fireRate;
 }

function FireOneShot () { var direction = transform.TransformDirection(Vector3.forward); var hit : RaycastHit;

 // Did we hit anything?
 if (Physics.Raycast (transform.position, direction, hit, range)) { //&amp;&amp;!= "Player"
     // Apply a force to the rigidbody we hit
     if (hit.rigidbody)
         hit.rigidbody.AddForceAtPosition(force * direction, hit.point);

     // Place the particle system for spawing out of place where we hit the surface!
     // And spawn a couple of particles
     if (hitParticles) {
         hitParticles.transform.position = hit.point;
         hitParticles.transform.rotation = Quaternion.FromToRotation(Vector3.up, hit.normal);
         hitParticles.Emit();
     }

     // Send a damage message to the hit object
         hit.collider.SendMessageUpwards("ApplyDamage", damage, SendMessageOptions.DontRequireReceiver);
 }

 bulletsLeft--;

 // Register that we shot this frame,
 // so that the LateUpdate function enabled the muzzleflash renderer for one frame
 m_LastFrameShot = Time.frameCount;
 enabled = true;

 // Reload gun in reload Time        
 if (bulletsLeft == 0)
     Reload();

function Reload () {

 // Wait for reload time first - then add more bullets!
 yield WaitForSeconds(reloadTime);

 // We have a clip left reload
 if (clips &gt; 0) {
     clips--;
     bulletsLeft = bulletsPerClip;
 }

function GetBulletsLeft () { return bulletsLeft; }

function Update () {

var position = Input.mousePosition; newposition = Vector3(position.x,position.y,-camera.main.transform.position.z); var lastposition = camera.main.ScreenToWorldPoint(newposition); transform.LookAt(lastposition); }

Answer 1

Answer by Mendicant · Dec 03, 2010 at 04:37 PM

I've actually just had to tackle a similar issue myself. I'm not sure this is the best way to do it, but it works for me.

Firstly I divide the damage types into an enum:

enum DamageTypes{
    player,
    enemy
}

On the Projectile I have a variable to store it's damage type, which I send with the hit message.

On the entity with the ApplyDamage function I have an array of damage types to ignore, I can then use that to process whether damage occurs.

function DealDamage(damage : int, damageType : DamageTypes){
    var blocked : boolean = false;
    for(var i : DamageTypes in ignoreDamageTypes){
        if(i == damageType){
            blocked = true;
        }
    }
    if(!blocked){
        hitPoints -= damage;
    }
}

I hope this helps somewhat towards your solution.

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Mendicant · Dec 03, 2010 at 04:39 PM 0

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As an aside, you could always get the array from the object being hit and process it in the projectile script if you'd prefer.

skovacs1 · Dec 03, 2010 at 04:47 PM 0

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The op is using SendMessage which only takes one parameter, so your answer would need to combine the damage and type into one type, but would it not be better to simply not call the function when it is not necessary?

Answer 2

Answer by skovacs1 · Dec 03, 2010 at 04:39 PM

The simple solution is where you do your Physics.Raycast check if hit.transform.tag != "Player" or something like that:

if (Physics.Raycast(transform.position, direction, hit, range)
    && hit.transform.tag != "Player") {

The more complete solution is to prevent them from pointing a gun at themselves probably by putting the player on a different layer and then using an appropriate layer mask in their raycast that does not include objects that they cannot hit (like themselves).

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Michael 10 · Dec 03, 2010 at 10:19 PM 0

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hit.transform.tag != "Player" worked perfectly thank you so much! I've been pulling my hair out not knowing the right syntax (you can see my sorry attempt commented out in the script). You are a life saver thank you!

Help make Machine Gun damage enemies and not player

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