# Homing projectile vs multiple targets

• @Aidan-Oxley I’ve never tried working with arrays before. Seems like I have my work cut out lol.

And where the heck is the set input field behavior? Am I needing to purchase an upgrade to have access to it or something?

• @Aidan-Oxley yes I thought the same thing. Both of us would actually compliment each other if we ever did decide to team up. It would be a force to be reckon with. Here’s a video of me showing a time lapse of something I did in photoshop a long time ago. Although doesn’t have to do with games but it kind of shows where my skills are at in terms of designing.

• When missile spawns, it will run this loop that will repeat the logic under it once for every target object that exists, and it will do this very quickly (this completely freezes hyperPad if the loop tries to repeat too many times, that's how fast they are). In the loop, it will get the ID of a target object and calculate the distance to it. It will group the ID and calculated distance together in an array with the order of distance, ID. Then it will store this information in another array, and move on to the next target object, if there is one. Once it's finished the loop, it will sort the array from smallest calculated distance to largest, then all it needs to do is get the data from the start of the array (because it's the smallest), get the ID of the object with that distance and go home in on it.

Don't know if this is helpful in understanding the logic, but there you go.

• @bosswave Press here:

• @Aidan-Oxley Really all you need to do is loop through a list of targets and keep track of which one is closest, no? Rather than sorting the whole array.

• @Jack8680 Yeah but that takes more behaviours :P need another box container to keep the minimum value, then get the minimum value every loop.

EDIT: actually Jack's idea is more efficient and probably takes same amount of behaviours, and makes me wonder why I did it the way I did in the first place.

• @bosswave you mentioned you want it to look at a group of spawned objects. Are these objects constantly spawning or do they spawn in once.

• @SplitMindGaming Doesn't matter. When the missile spawns or the homing logic is triggered, it will look at all objects that currently exist with the tag "target".

• @Aidan-Oxley We think in different ways when making something like this lol.

• @bosswave here’s my ghetto way of doing it. It doesn’t use arrays. Very simple logic really. But this only works assuming you already spawned in your objects. You can always just already have the objects spawned in but hidden away far off screen. Then have certain events move that object to scene when you want it. You will notice that this method does work and it will follow the closest square that’s next to it. So go ahead move each square next to the missile and it will follow the closest one. Maybe this can be a temporary approach until you learn arrays and know the ways of master aiden. Use safari to download and open this project.Homing missile.tap

• Here’s a video showcasing it follow the closest squareFullSizeRender.mov

• @SplitMindGaming I think Aidan's reworking his to not use arrays right now lol

• @Jack8680 yeah he’s about to poop on mine right now just wait for it.

• @bosswave Don't use the other example, use this one instead: https://go.aws/2zEM8XH
Jack made me realise what I was doing before is really over complicating the problem, this one is way simpler and doesn't even use arrays.

It's so funny how you can make something complicated, but then it ends up being dumb because of how simple it can actually be.

• @SplitMindGaming Haven't looked at yours yet, but I think the best way is something like this:

``````minDistance = -1;
foreach(potentialTarget in tag)
{
distance = CalculateDistance(self, potentialTarget );
if(minDistance == -1 OR  distance < minDistance)
{
minDistance = distance;
target = potentialTarget;
}
}
``````

Or if there's a maximum range, you can just do

``````minDistance = maxRange;
foreach(potentialTarget in tag)
{
distance = CalculateDistance(self, potentialTarget );
if(distance < minDistance)
{
minDistance = distance;
target = potentialTarget ;
}
}
``````

Too bad having an OR in hyperPad isn't quite the same as in a normal programming language; if you put two ifs next to each other connected to the same group of behaviours, it's possible for them to both be true and run the behaviours underneath twice, so it gets a bit messy.

• @Aidan-Oxley the thing I notice with yours is that it doesn’t follow the closest square. It only follows and locks on 1 target. It doesn’t redirect. Did u check out my video on how mine behaves?

• @SplitMindGaming It finds the nearest target ONCE, and chases that one forever. It can be told to redirect whenever you want, just activate the behaviour bundle called "Homing trigger" and it will redirect to the nearest target and then chase that one forever. For example: edit the project and add a timer and connect Homing trigger (with all the behaviours under it) underneath the timer. Don't make the timer too fast or you could lag/freeze the project if you have spawned in lots of targets. 0.5s would be fine.

I did look at yours. I moved the blue and green squares both to the top right of the screen and the missile just stopped and sat there.

• @Aidan-Oxley yeah I was going to say the same thing. When your missile hits the edge of the screen it just stops there and freezes.

• @Aidan-Oxley

• @SplitMindGaming If the object the missile is chasing gets deleted, the missile will stop and have nothing to do. In that case, you would want to add some logic to detect when its target is destroyed, and decide what to do then (e.g trigger homing again and select a new target, or just delete the missile). However if you get the missile to constantly redirect to the nearest target on a timer this shouldn't happen unless all targets are destroyed.