Unlike infantry, who have a clearly defined two-stage process of gathering information about an enemy player, vehicles instantly gain unfair knowledge about anyone who is firing on them.
To explain: when infantry hear a gunshot, they use the sound to make an inaccurate guess about the location of the shooter. Generally, they choose a certain radius of terrain where they believe him to be. They face towards that area and make a vision check. At this point, if there is line of sight between the player and the AI, the player is fully revealed to the AI.
But my tests have just convinced me that vehicles do away with this two-step system. Unlike infantry, vehicles tend to ignore gunshots fired nearby (except when very close). But if you hit a vehicle with a bullet, they will respond. The script I use shows them estimating your position based on the sound of the shot, just like infantry.
But the gunner of the vehicle will flat out ignore this estimate and aim at your exact position, even firing through completely opaque objects such as bushes to kill you with deadly accuracy! As soon as your shot lands, he knows your position and every step you take, even if you are in sufficient concealment.
To demonstrate this, I have made a repro mission.
1) Fire a whole magazine at the sky. This is to demonstrate that the Stryker ignores the sounds you make. He will not be alerted.
2) Fire a single round at the hull of the Stryker and immediately run behind the bush to your right. This type of bush provides complete concealment from infantry. You will reach cover before his periscope and gun turn to face your position, meaning he should not have seen you.
3) Wait for death.
Notice that before you die, you may see a circle of red smoke, with a white dot in the middle. This represents the area he thinks you are in based on your gunshot. It demonstrates that he is not using some perfect hearing ability to track you, because the circle will never close in around you. He is "seeing" you through the bush by a mechanism completely different than what AI infantry use.
And he is not using FLIR, because I have also tested this with a UAZ-mounted HMG. Not even a scope on that thing. Exact same behavior. This is a problem with vehicle classes versus infantry classes.
The thing is, my repro mission isn't elegant enough to remove all possible variables and fully convince the devs. So help me gather information and formulate a worthy ticket for the bugtracker.
IMPORTANT NOTE: I remember a ticket about vehicles having 360 degree vision when alerted. This bug would fully explain this cheating behavior, because the Stryker would have simply observed you run behind the bush, even though you were out of his scope's FOV. But I remember this bug getting fixed. But I also can no longer find it on the tracker. So if you have any information regarding this, please let me know.
Repro and unfinished ticket here: https://dev-heaven.net/issues/28203
Edited by maturin, 28 January 2012 - 21:01.