[Resolved] [Resolved] [Resolved] [Resolved] tank A I ?

i need to create a smart tank

i mean i need it to be able to see the other tank when the tank is close enough and i think i already got that
http://digilander.iol.it/magneto1/tank1.swf
the arrow in the that swf rappresent the enemie tank
lets call it tank2

now my main problem is this
how do i make tank2 follow tank1 in a way that may look realistic?
and when if it gets too close i think tank2 should stop and starting shooting

any suggetions??


thanks guys

cia:D

from waht i can gather from most games, an enemy will take a reading from one frame, and then shoot in a later frame.
so when an enemy gets too close you set the enemy angle to point to the player (mabey even calculate where the player will be in 5 frames if they don't change their speed/direction). then say 5 frames later you shoot.
great idea by the way. did you use hitTest() with the green square??
hope this helps
BlinkOk

you´ve got the right idea,blink,and magnetos one is good too.
i suggest you keep the current proximity check borders and
call that proxinner(or keep the naming it has now) and add a bigger checkarea and call it proximity outer.if proximity outer is true,the npc tank should move towards the players tank (get players tank x/y position and add in npcs x/y values until both are the same.
To make him stop at a certain distance,check if innerprox is true and if so,let him stop.make a turret out of the arrow and place the tankgraphic in a layer below it and let that one rotate in the direction where the tank moves (you can reuse the angle check you do for the arrow/turret right now)

hey magnetos did you get the idea from flash games studio?

i made a tank game from the tut in the book which is very close to this one, but i couldnt work out how to make the enemy fire the shells independantly from the turrent.

ok to gas attack
yes i took that from that book i just got it (cool book)
to make it work put the buller on the main stage
in the bullet you have this code
onClipEvent (load) {
if (String(_name) != "shot") {
cannonLength = 44;
turretpoint = _parent.tank._rotation+_parent.tank.turret._rotati on;
angle = (turretpoint/360)*2*Math.PI;
xcomponent = cannonLength*Math.sin(angle);
ycomponent = -cannonLength*Math.cos(angle);
_x = xcomponent+_parent.tank._x;
_y = ycomponent+_parent.tank._y;
xmove = (xcomponent/cannonLength)*10;
ymove = (ycomponent/cannonLength)*10;
}
}
onClipEvent (enterFrame) {
if (String(_name) != "shot") {
_x += xmove;
_y += ymove;
for (i=1; i<=_parent.level; i++) {
if (_parent["mine"+i].hitTest(_x, _y, true)) {
_parent.d++;
duplicateMovieClip (_parent.damagedGround, "d"+_parent.d, (_parent.d%100)+500);
_parent["d"+_parent.d]._x = _x;
_parent["d"+_parent.d]._y = _y;
_parent["d"+_parent.d]._xscale = 150;
_parent["d"+_parent.d]._yscale = 150;
removeMovieClip (_parent["mine"+i]);
removeMovieClip (this);
}
}
timer++;
if (timer>15) {
_parent.d++;
duplicateMovieClip (_parent.damagedGround, "d"+_parent.d, (_parent.d%100)+500);
_parent["d"+_parent.d]._x = _x;
_parent["d"+_parent.d]._y = _y;
removeMovieClip (this);
}
}
}


and this is the code for the space key press whic is on the tank mc (add it to the rest of the code )

if (Key.isDown(Key.SPACE) && shotTimer<=0) {
shotCount++;
duplicateMovieClip (_parent.shot, "shot"+shotCount, (shotCount%100)+1100);
shotTimer = 5;
}
shotTimer--;

ok this obviously si from that book (did i said its a cool book")
did you downloaded all the sample flas that go with that book?

to blink and tommason


thank you guys thats very cool but i was thinking about a small piece of code that can make the enemy follows the tank
maybe a little function? nothing complicated just follow him

i try to take care of the stop and shoot part
thanks again
cia:D

o yes i didnt use hit test for the proximity check

this is what i used

onClipEvent (load) {

dist=100;
}
onClipEvent (enterFrame) {
x2=_root.tank._x;
y2=_root.tank._y;
x1=_x;
y1=_y;
//check proxymity
if ((_parent.tank._x-_x<dist) && (_parent.tank._x-_x>-dist) && (_parent.tank._y-_y<dist) && (_parent.tank._y-_y>-dist)) {
_root.in_range = true;
}else{_root.in_range = false;}

if(_root.in_range){
r = Math.atan2((y2-y1), (x2-x1));//follow the tank movement
_rotation = ((r/Math.PI)*180)+90;
}
}

what u think?

hey there magnetos,
couldn´t sleep well,so i made a follow script for you
´didn´t look at your code but you should be able add the follow code where you need it (in your if inrange=true {...
codepart
to test it,add a square,make it an mc,add the following code to frame one (inside the square mc):

//just copy and paste
//the only thing you have to change:change _root.squarea. in the first to lines(below) to the path/mc name of your tank
newx = _root.squarea._x+65;
newy = _root.squarea._y-40;
distx = int(getProperty(this, _x)-newx);
disty = int(getProperty(this, _y)-newy);

z = (distx*distx)+(disty*disty);
hyp = Math.sqrt(z);
speed = 2;
//change speed for faster npc movement
distance = int(hyp/speed);
movex = distx/distance;
movey = disty/distance;
if (distance<=0) {
gotoAndPlay ("npcmoves");
//exchange npcmoves with target of your npc moving animation
} else {
setProperty (this, _x, getProperty(this, _x)-movex);
setProperty (this, _y, getProperty(this, _y)-movey);
distance = distance-1;
}


and this to frame two
gotoAndPlay (1);

the square mc will now follow your tank and stop shortly in front of it.
it can be done simpler and more complicated (depending on what you want it to do)
hope this helps for the start,if not tell me again tomorrow,i think i´ll go back to bed now ;)
[Edited by tomsamson on 03-06-2002 at 12:07 AM]

thanks a lot tom that worked fine
i go to sleep too now
good night

cia:D

Ok as TomSAmson pointed out the proximity check is done with Pitagoras theorem..

DX=(tank1._x-tank2._x)*(tank1._x-tank2._x);
DY=(tank1._y-tank2._y)*(tank1._y-tank2._y);
dist=maths.sqrt (dx+dy);


this also could be done with a prototype function from the main time line:

MovieClip.prototype.distance=fundtion(MCname){
DX=(this._x-eval(MCname)._x)*(this._x-eval(MCname)._x);
DY=(this._y-eval(MCname)._y)*(this._y-eval(MCname)._y);
return maths.sqrt (dx+dy);}

from any mc onclipevent call it like:

CurDistance=distance("tank2");

some tweeking maybe needed Im making this up on the fly..

ok now you know how far away the tank is. Now to make it more realistic you can make the speed dependand from the distance..if the tank is far away the speed is high and gradually declines as you get closer..

myspeed+=distance/ factor; try to play with the factor here some trial and err type of thing..

ok you can use atan maths to move in the right dir..

as for the shooting bulet..you can give each bullet a life:

each time the bullet leaves the tank just put a counter in it.. like:

onClipEvent (load){life=20;}
onClipEvent (enterFrame){life-=1;if life==0 remove..}

and with some trial and err you can calculate the distance the bullet traveled...

I think I have a sample code someware tomorrow Ill dig it out..

ciao ombre..:D

ms

ok is set up some simple code:

Code:

---

onClipEvent (enterFrame) {
X = this._x;
Y = this._y;
// rotate towards the hero..
        Xm = _root.hero._x;
        Ym = _root.hero._y;
        Xdiff = Xm-X;
        Ydiff = Ym-Y;
        radAngle = Math.atan2(Ydiff, Xdiff);
        this._rotation = radAngle*360/(2*Math.PI);
//move towards the hero..
        xx = math.cos(_rotation * math.PI / 180) * speed;
        yy = math.sin(_rotation * math.PI / 180) * speed;
        this._x +=xx;
        this._y += yy;
        }

---

keep in mind that it will try to cut you off

hope it helps

ms

::thumbs up::

It's the best book I've ever bought.

Mad-Sci is right. If you use prototype, you can save valuable filesize and speed of your movie. I myself use it as often as possible.

And using tan/sin/cos/pythagoras is the best way in games to calculate movement angle, movement and distance.

jeroen is right.
good work mad-sci

[sarcasm] Of course I am... [/sarcasm]


LMOA
Sorry, couldn't resist. :)

what´s up magnetos,any progress with the tank battle?I´m bored and would like to see it (not much work today)

thanks guys i havent got too far with this
i try mad dude code on the enemy thank but it doesnt work
i mean the tank tunrns but no following.

but the code tommason gave me works fine for a following chopper
http://digilander.iol.it/magneto1/tank1.swf

i gotta figure out a search a destroy function
for the tank

mucho gracias guys !! grazie !! merci!! tankenshen!!


:D hey mad-sci welcome back i thought you left us for good

Not yet my friend..not yet..:D

magnetos, that is gonna be one wicked game when your finished!
BlinkOk

thanks blink:Dk
but i usually start things and then leave them right when i am close to finish them
perhaps is because i already know the end...

now i am doing some hit test check any suggestions???

http://digilander.iol.it/magneto1/tank1.swf

ciao:D

I'm working on a space game that uses a facsimile of "true physics" for ships (there's inertia and an exagerrated level of friction). I still haven't worked out my NPC AI yet. Anyhow, my question is this: I think I can figure out the tracking/following bits, but how do you "dumb-down" the AI using the above methods? For instance, with the AI like it is, magnetos' game enemies will never miss a shot! Is there anyway to vary the "level of skill" for NPCs using the examples shown by TomSampson and MadSci?

Thanks,
TotalMonkey!

cool game :)

Quote:

---

Originally posted by TotalMonkey
I'm working on a space game that uses a facsimile of "true physics" for ships (there's inertia and an exagerrated level of friction). I still haven't worked out my NPC AI yet. Anyhow, my question is this: I think I can figure out the tracking/following bits, but how do you "dumb-down" the AI using the above methods? For instance, with the AI like it is, magnetos' game enemies will never miss a shot! Is there anyway to vary the "level of skill" for NPCs using the examples shown by TomSampson and MadSci?

Thanks,
TotalMonkey!

---

To dumb down the ai,you can give it timeouts (reloading times in which they don´t shoot),make them move slower (in my example,you only have to change the speed variable)and aim worse (add /** to the turret angle code(**being a number,the bigger,the worse the enemy will aim)so that it turns slower than the player moves his character.
You could also code detection/prediciton of past and future
position of the players unit and make the enemies aim for those rather than for the players unit.(good/skilled enemies aim for future position (prediction) whereas badly skilled ones aim for the past position).
Then you can combine this all depeneding on how dumb or skilled you want them to be and add if clauses defining in which situations they should act so (like if they are being shot,they can´t aim as good).