In-depth overpressure/HE mechanics

Game Discussion General Discussion
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Hi, I am a relatively new player (~1y or so) and was not around for pre-volumetric or hull break FWIW.

Do we know precisely, objectively how overpressure mechanics work?

From my experience, it seems that all projectiles (even things like sabot petals) are assigned a millimeter penetration table (programmatically I’d wager they all inherit some generic Projectile superclass/interface) which wholly dictates damage modeling (except for things like drowning, obviously).

We have all experienced the strange overpressure events wherein one errant particle from a seemingly-too-fucking-far-away HE detonation collides with our tank model, usually in some far-away place like the tip of the gun barrel, and the result is the whole crew is overpressured.

My theory is that HE, HEAT, bombs, and etc – upon detonation – create a dense particle cloud that emit omnidirectionally & isotopically from its detonation coordinates, and these particles essentially scan for collision of a relevant vehicle. They have some kind of time-to-live value before they disappear and might also (I think) have fixed number of bounces that can scan around and hit armor faces not otherwise hit from a perfect sphere evolving from the detonation point.

HE rounds have a penetration value listed, and I think this is what is checked for every explosion particle upon collision. Even though those values are usually very low compared to AP/etc, there is usually some part of a tank, e.g. on the roof or floor, that is is thin enough, and if a particle hits that armor face it counts it as a penetration, and then does a check on that round’s explosive filler equivalent to see if it is strong enough to overpressure. Maybe vehicles an assigned void space volume for the fighting compartment that affects this, e.g. a very cramped T-72 would need less HE filler to overpressure vs. something like a 2C.

That is my best guess as to how it works. Another guess…

Is more simply that explosives (upon detonation) simply create a sphere around the detonation point with the circumference positively correlated with HE filler value. And if a crewmember hitbox falls sufficiently within it, they’re overpressured.

But like I said, I haven’t been playing WT long enough to feel out how the underlying mechanics work in lieu of an official description.

Some open questions:

  • Is overpressure all-or-nothing? E.g., can only some of the crew members get overpressured and some survive?

  • Does explosion particle collision take into account the material type (as listed under armor analysis) ? I notice a lot of the BS overpressure clips usually have the explosion particle hitting the flat muzzle of the barrel, which could internally be modeled as “air” or something (as the gun barrel is obviously hollow) and this could screw with the game’s logic.

I would appreciate what any long-time players have to say here. I’d appreciate it if we could stick to what we know/what we can demonstrate instead of going off of gut instinct or vibes. I tried to have this discussion in Discord to zero luck & am hoping the good ol’ fashioned web forums might house some less ADHD folks.

Thanks,
TM

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Typically overpressure equates to one-shot. But it is possible for only part of the crew to be overpressured, particularly when firing shells with less explosive mass. Another example: in test drive, I hit the M1A1 with 5 kg explosive at the turret ring, knocking driver out only.

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nice work for a new player. close but not all correct. look into overpressure mechanics in-depth need a lot work in datamine, and you get very close by just observing.
all explosive rounds have a penetration value, directly connected to how much charge(TNT equal). it’s different from spall fragments penetration, spall’s pen is usually a little higher and reach farther.
when a chemical round hit, it runs a check, like you said, scan for collision of a relevant vehicle, though not “create a dense particle cloud”, anyway, it’s an IT issue, lets just put it away.
if the armor in it’s range is penetrated, then it comes to range judge.
there are trigger items in vehicles, almost everything in x-ray is trigger item, including the crew. they are separated into groups, each group stands for an independent cabin. if something in a group is triggered by explosive, it means this cabin is overpressured. this is how gaijin achieve separated cabins.
then it come to which one would be overpressured. it’s also a range, directly connected to explosive charge weight. if the charge is not much, like some APHE, usually over 150g and less than 200g, will not overpressure the whole vehicle if hit the corner.
most chemical rounds(HE, HEAT, HESH), have 2 additional parameters. radius and offset.
radius, is the limit of the explosion judge scan(not the overpressure range). offset is the offset range of explosion center.
image
usually, most HEAT/HESH’s offset is larger than radius, that’s why they usually overpressure only when hit in large angle.

this is usually caused by server bug or group set error

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