ACE3/docs/wiki/feature/advanced-ballistics.md

layout	title	description	group	category	parent
wiki	Advanced Ballistics	The advanced ballistics module improves internal and external ballistics.	feature	realism	wiki

1. Overview

The Advanced Ballistics module improves internal and external ballistics.

1.1 Features

• Drag modelling based on real-world ballistic coefficients.
• Ambient air density (air pressure, temperature, humidity) affects drag.
• Wind affects drag and deflects the trajectory.
• Wind speed varies with altitude.
• Terrain features, buildings and other objects disrupt the wind.
• Magnus effect (spin drift)
• Coriolis effect and Eötvös effect (Earth rotation)
• Loss of stability during transonic flight.
• Variable muzzle velocity based on powder burn rate and barrel length.
• Bullet trace effect for supersonic bullets (light refraction due to air pressure waves).
• A protractor for quickly measuring the inclination angle.

2. Usage

2.1 Protractor

Press Ctrl+⇧ Shift+K while using a compatible weapon to toggle the protractor. The red line indicates the current inclination angle in degrees. The protractor will disappear if you lower or holster your weapon.

3. Dependencies

ace_ballistics, ace_weather, ace_modules

4. Addon Configs:

Reference https://github.com/acemod/ACE3/blob/master/extras/CfgAmmoReference.hpp for examples of bullets with correct configs. It is probably best to modify an example that's close to the bullet you are trying to add.

ALL VALUES ARE IN METRIC

4.1 CfgWeapons (Example M4):

• ACE_barrelTwist=177.8;

  1:7 inch rifle twist

  7 inches * 25.4(mm/in) = 177.8 mm Same as the Capital T in https://en.wikipedia.org/wiki/Miller_twist_rule (convert to metric)

• ACE_barrelLength = 368.3;

  14.5 in (370 mm)

  Self explanatory

• ACE_twistDirection

  Right handed is 1, Left is -1, none is 0 Leaving blank will default to 1 (Almost everything is right-handed) A smooth-bore gun (e.g. shotgun) would be 0.

4.2 CfgAmmo (Example B_556x45_Ball):

• ACE_caliber=5.69;

  Bullet diameter in mm (diameter is a little different from caliber)

• ACE_bulletLength=23.012;

Bullet Length in mm

• ACE_bulletMass=4.0176;

  Mass in grams (example is roughly 62 grains)

• ACE_ammoTempMuzzleVelocityShifts[]={-27.20, -26.44, -23.76, -21.00, -17.54, -13.10, -7.95, -1.62, 6.24, 15.48, 27.75};

  Array of muzzle velocity shifts in m/s with 11 data points from -15 °C to 35 °C Example: At 0°C the shift will be -21.0

• ACE_ballisticCoefficients[]={0.151};

  Array of ballistic coefficients (contains one element more than the velocity boundary array)

• ACE_velocityBoundaries[]={};

  Array of velocity boundaries

• ACE_standardAtmosphere="ASM";

  "ASM" or "ICAO"

• ACE_dragModel=7;

  Number that specifies the drag model [1, 2, 5, 6, 7, 8]

• ACE_muzzleVelocities[]={723, 764, 796, 825, 843, 866, 878, 892, 906, 915, 922, 900};

  Array of muzzle velocities (same size as barrel length array)

• ACE_barrelLengths[]={210.82, 238.76, 269.24, 299.72, 330.2, 360.68, 391.16, 419.1, 449.58, 480.06, 508.0, 609.6};

  Array of barrel lengths (same size as muzzle velocity array) Example, when shooting with the M4 barrel (368.3mm). The length is between the 5th and 6th barrelLengths (360.68, 391.16). So the muzzle velocity will be between 5th and 6th muzzleVelocities (866, 878).

5. Dependencies

{% include dependencies_list.md component="advanced_ballistics" %}