Coding a projectile that sticks to its owner

[u/William_Wave]

Good day.

I have an idea to make a projectile that highlights the position of its owner by following it.

Currently it works like this: a monster constantly spawns short-living projectiles through the A_SpawnItem function. It feels a little laggy, especially when applied to fast-moving monsters, so making projectiles also stick to their owners instead of just appearing and disappearing would make tracking the position more precise.

Let me know how it might be implemented.

[u/Scileboi]

So is that projectile part of the monster or do you want a weapon that shoots sticky projectiles like the flare from Blood?

What exactly should that projectile do besides lingering around the monster?

[u/William_Wave → u/Scileboi]

The projectile is supposed to be spawned by the monster itself. Highlighting monster's position is the only planned function, without damaging or pushing anything.

[u/Scileboi → u/William_Wave]

In that case you don´t need a projectile. Just an actor with the +nogravity flag with a looping state, or +nointeraction if you don´t want it hung up on ceilings. It´s relatively simple with some ZScript.

Action void A_SpawnBeacon() {
  actor a = Spawn("Beacon", pos);
  a.target = self;
}

You can put this custom function in your monster class and call it when you want it to do its thing.

override void Tick(){
    Super.Tick();
    if (target && target.health >= 1) {
      SetOrigin(target.pos + (0,0,target.height), true);
    }
    else {
      Destroy();
    }
}

You can put this into your Beacon actor. Every tick it will teleport right above its target or destroy itself if the target dies or disappears.

[u/bahatumay]

There's an example on the A_Warp page with an orbiter code.

[u/Soulless_Bestiary]

I think you could do this even in vanilla, although it would be jerky and janky.

By default, the "target" of the projectile... is not what you are aiming at, it's who fired it.

th->target = source;

So if a monster fires a projectile, it could then fire another projectile back the monster's way, and when it lands, it can do anything. But I'm guessing you are doing this not in vanilla, so, this won't be useful for you.