Does projectiles inheirit velocity ? and does speed impact AP ?

[Type98]

Does the projectiles in the current game inheirit velocity from the chasis ? It probably matters more with the faster vehicles, but it is hard to tell right now whether they do or not (doesn't appear to have an entry in the projectile xml files either).

There is speed entry associate with the gun object. Does this impact the penetration value of the AP projectiles ?

[aittam]

AP loses penetration capability with distances not the others

[Type98]

Lets see if this can be made clearer.

- An AP projectile is an Kinetic Energy projectile.

- The higher the Kinetic Energy of an AP, the better the penetration (assuming the projectile does not shatter on impact nor does it overpenetrate).

- Kinetic energy is determined by the velocity squared (or 1/2*m*v*v).

- Currently the projectile and gun in DropTeam is two different objects.

- The projectile has a penetration value.

- The gun has a speed value.

- The question to the DT developers is whether the two values (gun speed and penetration value are tied together).

- In other words, is the penetration value of the projectile group affected by the gun speed? Or are they two independent variables?

[aittam]

gun speed it's so low compared to the round's one that should be almost not influent at all, no?

[Mace]

Originally posted by Type98:

Does the projectiles in the current game inheirit velocity from the chasis ? It probably matters more with the faster vehicles, but it is hard to tell right now whether they do or not (doesn't appear to have an entry in the projectile xml files either).

There is speed entry associate with the gun object. Does this impact the penetration value of the AP projectiles ?

Because the speed of the vehicle is extremely small compared to the velocity of the AP round, I think you'd find that the vehicle's velocity will contribute little to the round's Kinetic energy.

Eg if the Velocity of the vehicle is 1/100th that of the AP round, then the contribution the vehicle makes to the AP velocity vector would be +0.001V, and so the KE would have an additional 0.001x0.001 contributed, which is miniscule.

Of course this doesn't consider factors like AP round terminal velocity due to atmospheric resistance etc

[sillyb]

So if you are driving 100km/h parallel to your target you don't have to lead/trail at all?

[RIPper_SVK]

the speed of the vehicle won't add to the penetration. but if the projectile retains vehicle speed, it sure is important to know this for gunnery. you've got to aim at different spots if the projectile retains or doesn't retain the vehicle's speed.

[Type98]

Hmmm,there were two questions, however, most readers combined the two and made it rather confuzing.

The first is whether the projectile inheirits velocity from the vehicle. That impacts aiming and accuracy of the projectile. Do you need to lead to compensate for your vehicle speed ?

The second question was related to how the xml files read in regard to the gun physical object and the AP projectile physical object. As only penetration values where listed under the projectile xml file and no velocity values, this could be taken as that the projectile can potentially penetrate to its maximum value even at speed=0. The gun has speed values, hinting that projectiles fired from this gun gets this velocity.

So if you want to modify the penetration of the AP projectile, do you modify just the velocity of the gun or the penetration value of the AP projectile ? In other words, what is the real penetration value of an AP projectile ?

[aittam]

first one yes you have to!

[Drusus]

Originally posted by Type98:

The second question was related to how the xml files read in regard to the gun physical object and the AP projectile physical object. As only penetration values where listed under the projectile xml file and no velocity values, this could be taken as that the projectile can potentially penetrate to its maximum value even at speed=0. The gun has speed values, hinting that projectiles fired from this gun gets this velocity.

So if you want to modify the penetration of the AP projectile, do you modify just the velocity of the gun or the penetration value of the AP projectile ? In other words, what is the real penetration value of an AP projectile ?

I know that the distance is taken into account when calculating if a shot will penetrate. This is propably done through calculating the velocity of the projectile. I don't have a clue if the muzzle velocity has an effect. Working, so no game here. But it is easy enough to test:

1. Modify the values.

2. Start your own server.

3. Play at your own server. The easiest way to test penetration effects is to fire at your teammates. Bots, hopefully. You can check in game what is happening through the tactical map. Also a great way to learn where the components are.

4. Quit & kill your server process.

5. Read the log files. See how your modifications changed the penetration.

6. Goto 1.

[yurch]

The way lag works, often times I find myself firing the opposite direction you would ordinarily expect to lead (while the shooter is moving quickly sideways). It depends on whether or not you keep the crosshair over the target the entire time, or let it roll over the target as you move past it. If you let it roll, it appears you should let it roll past the target.

Think of it as if the shot originates where your vehicle and crosshair orientation were a few ms ago. Aggressively keeping the crosshair on the target during the few ms before the shot appears to validate this, as the need for the 'rolling lead' is eliminated. If the target is moving, you would have to keep the crosshair at the desired ordinary-lead region.

(Presuming I'm correct about all this...) This netcode method of course is in no way problematic, and it works well considering the alternatives, especially for a slower paced gunnery-based (and not a dodging-based) game like this. Without getting into the miserable specifics of all the different netcode styles out there, I think the way we already have is the most visually consistant method, and I wouldn't want it changed.

This is good to know, when operating very quick craft or in high lag situations. If shooter velocity imparts any actual movement on the shell or not, I cannot tell, as lag displacement is a hard factor to seperate it from. Initially I would say no.

[ClaytoniousRex]

Type98, the 2 variables you're talking about are independent. At runtime, as AP projectiles decelerate due to air resistance over time, their penetration decreases. But their initial penetration is independent of their initial velocity as far as the physics engine is concerned. So if you, as the author of a mod, raise the initial velocity of an AP projectile, it would make sense for you to also raise its initial penetration correspondingly. They're independent from the engine's standpoint to maximize flexibility, not to pretend that the 2 aren't related in reality (keeping them independent lets you tweak them relative to one another).

As for your second question: no, projectiles do not inherit the shooter's velocity. This is a simplification that makes gunnery easier without having much effect at all on simulation fidelity.

[Type98]

ClaytoniousRex, thank you for the reply.

IMHO a note in regards to "no inheriting velocity" needs to be added in the manual because it changes the lead of projectile weapons and viable tactics (high speed firing passes).

[Morat]

It also makes hovercraft rather more deadly than they should be imo