flash actionscript: I have spaceships that shoot lasers, lasers are class instances extending
movieclip. On every frame, lasers do a hitTest to determine if it collides
with an opponent ship:

function onEnterFrame() {
if(this.hitTest( _root.gm.opponent) ) {
_root.gm.opponent.recieveHit(this.damage);
this.gotoAndPlay("hit");
}
}

*'this' refers to the laser instance

I have also tried ( _root.gm.opponent.hitTest(this))

both return false - no collision - even when there is one

anyone know what might be going wrong?

i have done the exact same thing u did

if (this.hitTest( _root)){
_root.gotoAndStop( 2 );

A odd problem... where the script are localized ? Inside a frame of main
timeline or in the mc ?
Usually i do it:
1)select the Enemy MC
2)Call F9
3)Put this script inside the script of MC (not in the internal timeline):
onEnterFrame(){
if(this.hitTest(_root.collisionObject)){
//put my code here
}
}

4)Or in the internal timeline (but the MC must loop in this frame):
if (this.hitTest(_root.collisionObject)){
//put my code here
}

the script is within the laser's class:

class laser extends MovieClip{

function onEnterFrame() {
if(this.hitTest( _root.gm.opponent) ) {
_root.gm.opponent.recieveHit(this.damage);
this.gotoAndPlay("hit");
}
}
}

You can out it inside the class constructor

this.onEnterFrame = function(){
//your hit test code
}

i actually have the class constructor already written as:
function Laser() {
var dist = Point.distance( new Point(0,0), gunPt );
var theta = Math.atan2( gunPt.y,gunPt.x ) + ship.heading;
var cP = Point.polar( dist, theta );
this._x = ship._x + cP.x;
this._y = ship._y + cP.y;
origin = new Point(this._x,this._y);
heading = this._rotation*Math.PI/180;
initXspeed = ship.xSpeed;
initYspeed = ship.ySpeed;
}

to create the classes as movieclips i used:

var opponent = _root.attachMovie("linkID","instName",depth,vars);

A movie created with "attachMovie" is a common MovieClip object ,not your
extended mc . You must associate the variable "onEnterFrame" with a function
after the movie is attached.
an example:

ColideFunction = function(){
//my hittest function
}
var my_enemy =
_root.attachMovie("enemy_instance","enemy1",depth,{onEnterFrame:ColideFunction}

or attach the enemy mc and later
my_enemy.onEnterFrame = ColideFunction;

well i left out code to lessen details, i typecast my attached mcs, therefore
anythign I define in the type classes, such as onEnterFrame, is inherited
automatically when typecasted:

the focus of my problem lies within the hitTest function. My mcs' onEnterFrame
are functioning correctly, i have a few different extended classes. hitTest
merely isnt returning true when the two mcs are overlapping. I have assigned
static depths for both spaceships and the lasers are created starting at 1000
depth.

I think maybe the hitTest problem has something to do with the hitAreas of my
MCs. Does anyone have experience using hitAreas and hitTest?

What I want to do is use only the (x,y) coord at the tip of the lasershot to
test if its within the spaceship's coordinates, to do so I have tried hitTest
in this fashion:(*'this' refers to the lasershot instance, as the code is
written inside my onEnterFrame function of the lasershot class ).

_root.gm.opponent.hitTest(this._x,this._y,true))

i know this is correct usage, yet it never returns true...

i have also tried this inside my onEnterFrame for laser:

//-use the ship MC as the hitArea
this.hitArea = _root.gm.opponent;

//-if the laser's registration point lies within the ship MC hitArea
if( this.hitTest(this._x,this._y,true) ) {
// collision success - call resolving functions
}

-this does not work unfortunatly. what i expected was to use hitTest on the
laser hitArea to determine if the laser's point overlaps. hitArea is defaulted
by its movieclip owner, but i reassigned it to the opponent ship, so it should
still test the coords against the ship's Area, right?

You can calculate the hit by yourself by the heigt values and widht.. but it?s
not easy if your mc has a form diferent than a box.
Its too strange the hitTest return false ,I will see your problem later
becase here (my office) i dont have Flash installed.

yea, i was about to just use a bounding box for collisions and calculate the
coordinates on my own, but i am determined to get the hitTest working
correctly, i really want the collisions to detect using the ship's graphic
instead of a box.

thanks for the help, i apprecaite it.

Ipdont shure if it?s the same problem but if you do this:

mymovie = this.attachMovie(blablalal...);
if(mymovie.hitTest(anyMc)){
trace("Collision");
//collision case code
}
else{
trace("No collision !")
}

this code always trace "no collision" and it?s not a bug.This occurs because
the attached movie will be present after the execution of the script of the
current frame .