Melee Gun Thrashing

I've observed a few times Neuromancer's gun thrashing pretty badly - sometimes doing a full circle before firing. I'm currently trying to avoid this by accounting for an extra of max(time-till-gun-turns-to-angle,time-till-gunheat-is-0) in my PIF time, but I wonder if anybody else has come up with some way to avoid this problem?

So is your firing condition just that the previous tick's aiming completed? And if it didn't, you re-aim? That's all I do and I haven't noticed thrashing, but I don't watch as many Melee battles as I probably should. Projecting extra ticks in the PIF seems like a good idea. Maybe also try adding a factor into the kernel density evaluation that penalizes angles that will make you fire late?

Yeah, that's it. I'm hoping that the extra PIF ticks will cause more spread in the enemy movement, correctly accounting for the increased uncertainty, but I think with the sample sizes we are looking at that isn't really good enough. Perhaps there are points hiding in not going for angles which will take a 180 degree gun rotation, although I really doubt it...

Not sure if you did this already but you could try to bind the targeting to the gun heat. The closer it comes to zero gun heat the less it changes the once found target/area. But i guess if your gun shoots 'blind' you have to weight the new (maybe better target) to the couple of turns you might loose. Because especially in the beginning of the battle 'trashing' is not that bad if your radar detects an enemy that is sneaking up to you (in this case i wouldn't call it trashing - its more likely an emergency reaction). Overall i would guess your targeting is a little to picky dependent on your movement and battle state. Its like 'oh this one is nice ... no wait this one ... oh hang on, this one looks nice ... hello what are you doing right behind me?' :) So i guess you can just let the targeting more space (dependent how many opponents left) to pick a target/area and should be fine.

I found I was waiting for this tick's targeting to align to within 40/distance of the current gun angle before I would fire, so now I just wait for the current (getGunTurnRemaining() == 0 && getGunHeat() == 0) and then I fire. This will lower my accuracy, but I will fire much more often, so I'm interested to see what will happen!

I guess this makes no difference. If the targeting is sound, it should be within 40/distance on this turn as it is at zero at the next turn. Anyway, this will not solve your trashing issue :). If the gun is on its way to lets say PI and the next turn the targeting decides no its not PI its PI/2 your gun will trash between the targets and will not shoot at all for the time it 'trashes' between two headings.

I think the trouble is if there is say a peak at 3*PI/4, and another at 7*PI/8, and both are almost of the same likelihood, then even though the gun can easily turn to both, if they keep changing which is better then I might never end up shooting. Now, as soon as I have a single tick which the best angle changed less than MAX_GUN_TURN_RADIANS, I will fire next turn. Although it seems I have lost some score with this version, so maybe it was better before??? I know I need to do some serious work on my gun, it matches vs all the top bots I get much lower bullet damage.

Yes thats how it works if you take gunTurnRemain() before fire() (worst case is checking against 0) but with 40/distance you have a good value that it happens very rare. You just have to decide whats better for you - shooting one tick earlier (with 40/distance) or shooting more precise with one tick later (zero check). I spend quite a while on this issues and finally decided to go all the way with zero check. You also have to decide what bullet power to use - the one that is used to calculate the angle or the current one. Both have some pros/cons to. Shooting if the last target is not the same as the current target is also something you have to decide.

Hmm its hard to explain for me right now but even with zero check you can end up with not firing. If your gun targeting constantly decides to change the target/area your gun will never (at least less often) be zero as you wish. That mostly happens on loose radars, every time the radar sweeps to the opposite side and finds a better target the gun begins to rotate to this point - the radar sweeps back and decides oh this target is better (consider the movement as well) so the gun has not finished its turn and gets a new target - and so on.

A quite good test to see if your gun has trashing issues related to your movement is putting your bot against 9 Sitting ducks. If he misses some shoots or break the fire frequency to often you have something to change.

If it comes to score, my experience tells me that +-0.3 after 5000 battles translate to no change at all. I see you have a 0.04 difference and this is clearly equal to the last version. In melee it depends on what start battles you get to bring all the pairings up. I have seen jumps of 0.8 score even after 15k battles just because the start battles where to easy.

Maybe it helps: i have a test bed of some sample bots (always the same) and let it run 100 rounds ... i call it 40k/100k+ challenge. 40k = 100 firsts 100k+ = dmg. If your bot loose just one round he has some radar/movement issues. If he gets less than 100k dmg the gun need some changes. To be one of the top bots i guess you have to try 110k+ or more. I use this challenge almost exclusively to decide if i had made progress or not, because it runs fast and has almost every battle state i have to take care of in it. I might be wrong with it but it served me well so far.

Take Care

edit: not sample melee bots just sample bots

Using Swarm Targeting with gaussian kernel density usually gives a single angle which doesn´t change often.

Gun thrashing means the bot keeps changing its mind every tick. Usually happens when you target the closest bot and there are 2 or more bots with similar distances.