koobas.hobune.stream
Tower defense, turret aiming wrong.
So, im making a TD game, and im trying to make the turret shoot at the closest enemy in a sphere collider, but instead it just shoots at the newest enemy to enter the sphere collider attached to the turret
Heres the code, mind you i havent added in little things like checking if the turret has a target yet and whatnot, mostly because ive been stuck on this for about a day and a half :\
var Target : GameObject;
var TargetList = new Array();
var DistanceVector : Vector3;
var TargetPos : Vector3;
var TurretPos : Vector3;
var ShortestDistance : float = 9999;
var Distance : float;
function Start ()
{
TurretPos = transform.position;
}
function Update ()
{
FindEnemy();
transform.LookAt(Target.transform.position);
}
function OnTriggerEnter (col : Collider)
{
if (col.gameObject.tag == "Enemy")
{
TargetList.Add(col.gameObject);
}
}
function OnTriggerExit (col : Collider)
{
if (col.gameObject.tag == "Enemy")
{
TargetList.Remove(col.gameObject);
}
}
function FindEnemy()
{
for(i=0;i<TargetList.length;i++)
{
TargetPos = TargetList[i].gameObject.transform.position;
DistanceVector = TargetPos - TurretPos;
Distance = DistanceVector.magnitude;
if(Distance < ShortestDistance)
{
Target = TargetList[i].gameObject;
ShortestDistance = TargetPos.magnitude;
}
}
}
Hey
There's a little bug on line 50: ShortestDistance = TargetPos.magnitude;
Which should be: ShortestDistance = Distance;
Also worth noting you've got a lot of variables there that are member variables but could just be local variables. For example: TargetPos, DistanceVector, Distance and ShortestDistance are only used inside FindEnemy. TurretPos is also just a copy of transform.position.
I'd be tempted to remove those variables from the class definition and just have something like:
function FindEnemy()
{
var shortest_distance : float = float.MaxValue;
for(i=0;i<TargetList.length;i++)
{
var offset : Vector3;
var target_pos : Vector3;
var distance : float;
target_pos = TargetList[i].gameObject.transform.position;
offset = target_pos - transform.position;
distance = offset.magnitude;
if(distance < shortest_distance)
{
Target = TargetList[i].gameObject;
shortest_distance = distance;
}
}
}
Basically minimizing my use of shared variables or duplication of data. Trying to stick to those rules really helps minimize bugs.
-Chris
thank you, it works cleaner now, but unfortunetly im not sure how to get the result i want, it will stick to a single target until it kills it, and Then it will find the closest, i want it to always shoot the closest target no matter what.
I also have a bug where if two turrets are targetting the same enemy and it dies, the turret that Did not kill the enemy will stop ai$$anonymous$$g and shooting and will spit this bug : $$anonymous$$issingReferenceException: The object of type 'GameObject' has been destroyed but you are still trying to access it.
i attempted to fix it with Targetlist.Remove in the shoot function:
function Shoot()
{
Debug.Log("I shot");
Target.GetComponent("Pathfinding").ApplyDamage(5);
if(Target.GetComponent("Pathfinding").Health <= 0)
{
Destroy(Target.gameObject);
TargetList.Remove(Target.gameObject);
Target = null;
}
}
but alas that does not work
Hmmm. Assu$$anonymous$$g you have taken my code exactly as I wrote it, and you are still calling 'FindEnemy' every frame (from Update), it should always get the closest one. Would you like to just post your updated code here or in your original question so we can see the whole thing.
-Chris
This is the code im using currently
var Damage : int = 5;
var ShootTime : float = 1.0;
var Target : GameObject;
var TargetList = new Array();
var Timer : float;
function Start ()
{
TurretPos = transform.position;
}
function Update ()
{
Timer += Time.deltaTime;
if(Target == null)
{
TargetList.remove(Target);
}
FindEnemy();
if(Target)
{
transform.LookAt(Target.transform.position);
if(Timer >= ShootTime)
{
Shoot();
Timer = 0;
}
}
}
function OnTriggerEnter (col : Collider)
{
if (col.gameObject.tag == "Enemy")
{
TargetList.Add(col.gameObject);
}
}
function OnTriggerExit (col : Collider)
{
if (col.gameObject.tag == "Enemy")
{
TargetList.Remove(col.gameObject);
}
}
function Shoot()
{
Debug.Log("I shot");
Target.Send$$anonymous$$essage("ApplyDamage",Damage);
}
function FindEnemy()
{
var shortest_distance : float = float.$$anonymous$$axValue;
for(i=0;i<TargetList.length;i++)
{
var offset : Vector3;
var target_pos : Vector3;
var distance : float;
target_pos = TargetList[i].gameObject.transform.position;
offset = target_pos - transform.position;
distance = offset.magnitude;
if(distance < shortest_distance)
{
Target = TargetList[i].gameObject;
shortest_distance = distance;
}
}
}
And its kinda working, but i get an $$anonymous$$issingReferenceException: The object of type 'GameObject' has been destroyed but you are still trying to access it.
and i tried to fix it with:
if(Target == null)
{
TargetList.remove(Target);
}
But every now and again it still happends, and the turret will ignore all enemies that were in its range when another tower killed its target until a new enemy hits the collider
