[X:CE 0.35] Alien AI throwing grenades over walls without having vision.

[Ataman]

Hi there!

I gotta say, Xenonauts: Community Edition is really great so far and I love it, this one bug though...

Screenshot:

Description:

Well yeah, put your guys on walls, get nades thrown at you. With pinpoint accuray no less. Happened on 4 different locations so far which makes me believe it's not just a fluke. In the gif, they threw actually 2 nades...

Reproduction:

Using the provided savegame, put multiple soldiers at the wall, skip a few turns. One time they threw them right on the first turn, it usually takes a few turns. There is another alien coming up from the left which can be dispatched with the hunter. Killing the alien on the left or not doesn't seem to make any difference however.

No additional mods used except for the stuff that comes with X:CE

 

Wallhacking Aliens.sav

[drages]

Enemy AI can hear voices ( footsteps, gunshots), can calculate possible positions and if an enemy saw you, it can inform others about your position.

They are team as well, they communicate. Think that you play as aliens and you can detect enemies by their sounds even you don't see them.. what would you at that situation?

Many people think it's a bug but it's something at code. 

[Ataman]

I would be inclined to believe you if those granades would happen to land at approximate positions. It also doesn't seem fair for the aliens being able to use sound for calculating my teams position if I can't use the same mechanic for my own team.
If this behaviour really isn't a bug, then it's a bug that you as a player have absolutely no capability to use sound as well. The light scout drone going completely silent as soon as it enters a dark tile isn't really fair now, is it?

Also, the pinpoint accuracy EVERY time makes me believe it's not just approximates based on "sound" information. The AI throws their grenades always perfectly on your head. Meh, a hunter scout engine alone should be capable of masking a few footsteps in the grass shouldn't it?

In my honest opinion, I'm all in for more intelligent AI. However, based on testing, I don't believe grenade throws to be a result of intelligence. Just the simple fact that when throwing grenades, the AI always exactly knows where you are and NEVER misses.

EDIT: Also, if they're supposed to know my position so exactly, why don't they just shoot me with rifles instead?

Edited August 6, 2018 by Ataman

[drages]

Yeah ai is a bit capable of things more then it should be. Ai always throws when they see people together. So if you don't want grenade just don't hug each other. 

You are never safe! 

[Solver]

It's a combination of both things. The AI knows where you are most likely because of sound. The AI likes to throw grenades at shield carriers, and it really likes throwing grenades at groups of soldiers - so a group around a shield is the ultimate grenade magnet. And then there's walls, along with some doors, messing with accuracy in general. You may have noticed that you can throw grenades at a closed UFO door and still hurt the aliens inside. A combination of these behaviours is probably what leads to the situation in the first post.

Also, aliens definitely can miss with grenades. I agree they're a bit too accurate though compared to your own soldiers, but aliens can miss and can even end up hitting other aliens with a grenade.

[Charon]

@SolverI agree with it being a combination of not being able to directly shoot at a xenonaut soldier ( accuracy = 0 ) and "sound". With my limited experience with vanilla and Xenophobia i can still say that the aliens do get too much information where they shouldnt have that much, eg. even with 0 sight they accurately throw right in the middle of grouped up soldiers, which the OP shows, only moved up to a wall and no other "sound" was made.

Conclusio: Aliens get too much "sound" information even when the only action that happened was walking, and no direct line of sight has been made whatsoever. So the "sound" ripples should be tweaked to not give such accurate positions away.

[Ataman]

Question: Do aliens technically create those sounds as well and is it possible to visualize these ripples perhaps? Because to be honest, I think it's great the AI can use sound as a means to locate your approximate position but if this mechanic is in the game, the player should have the same information. Otherwise it's just basic cheating. Period.

I mean, if the aliens can hear us and throw perfect grenades just from that sound information, we should be able to hear them walking around on the other side as well so that we can avoid putting our poor guys in danger in the first place.

Currently, we're incapable of 'hearing' the aliens, even huge metal ass bipedals don't make the slightest noise. (Of course they play audio when you can see them, but from a gameplay perspective they're completely silent to us).