Welcome to symthic forums! We would love if you'd register!
You don't have to be expert in bit baking, everyone is more than welcome to join our community.

You are not logged in.

## Can someone expain ballistic coefficient ??

Hey! If this is your first visit on symthic.com, also check out our weapon damage charts.
Currently we have charts for Battlefield 3, Call of Duty: Black Ops 2, Medal of Honor: Warfighter and Call of Duty: Modern Warfare 3

Heretic

Posts: 210

Date of registration
: Dec 21st 2016

Platform: Xbox One

Location: Spokane, WA, USA

Battlelog:

Reputation modifier: 3

Friday, January 27th 2017, 11:59pm

### Can someone expain ballistic coefficient ??

Most guns have a ballistic coefficient of 0.0025 or 0.002 I understand this is the stat responsible for drag but how exactly does this work?
Official heretic of the Symthic forums. Avid M1907 factory user and complete casual pleb.
Iplaysgames96 - Profile Overview - Battlefield 1 Tracker

PvF 2017 Champion

Posts: 7,285

Date of registration
: Apr 3rd 2012

Platform: PC

Battlelog:

Reputation modifier: 19

Saturday, January 28th 2017, 12:18am

First approach to air drag model in BF1

### Quoted from "Labby"

I don't see any reason why the realistic drag formula wouldn't be used over the simplified one. It wouldn't really be any more complicated to set up in game either way. Bullet positions aren't solved analytically, they're integrated frame by frame from velocity, which is integrated from acceleration.

The numbers make sense too. Just use the drag equation and F=ma, then just solve for acceleration and roll everything that isn't velocity into a single constant, drag.

Instantaneous acceleration = v^2 * drag

For G98, that would be 880^2 * 0.0025 for the first frame, or 1936m/s^2 acceleration, which seems really high, but remember it's applied over a short time. At 60 frames per second, that would be around 32m/s less for the next frame.

For the second frame we'd have 848^2 * 0.0025, which is 1798m/s^2, and -30m/s in the next frame.

For the third frame we have 818^2 * 0.0025, 1673m/s^2, and -28m/s in the next frame.

The bullet would have a velocity of ~790m/s on the fourth frame. I'm stopping here, but the math would keep repeating for each frame.

To get position we just multiply the velocity in the frame by the delta (1/60 for 60fps) and then sum them.

So first frame gives a travel distance of 14.667m, second 14.133, third 13.633, fourth 13.1667, etc.

Summing those we get a travel distance of around 55.6m, for an average velocity of 834m/s for the first four frames. The more frames we calculate for, the more average velocity will be reduced by drag.
Data Browser

Passive Spotting is the future!

"Skill" may indeed be the most magical of words. Chant it well enough and any desire can be yours.

Are you a scrub?

### Quoted from "blahdy"

If it flies, it dies™.