openballistics 0.3.1

OpenBallistics is a high-performance, lightweight, header-only C++ library with native Python bindings for projectile trajectory prediction and firing-solution solving. It is built to reliably answer two core questions: Where will this projectile land? and How do I need to aim to hit my target?

Capabilities

• Trajectory Prediction: Compute a projectile's final impact position or full sampled flight path over a given time of flight.
• Direction Optimizer: Find the best-effort launch direction or angles toward a stationary target at a known time of flight.
• Direction Solver: Find the required launch direction or angles to hit a stationary target, returning no solution if miss distance exceeds a threshold.
• Time-of-Flight Optimizer: Find the time of flight that brings the projectile closest to a stationary target, given a fixed launch direction.
• Time-of-Flight Solver: Find the time of flight that hits a stationary target within a miss distance threshold, given a fixed launch direction.
• Intercept Solver: Jointly solve launch direction and time of flight to intercept a moving target given its position as a function of time.

All solvers accept an optional platform velocity to account for a moving launcher, and support earliest or latest solution priority where applicable.

Physics Models

• Aerodynamics: Mach-dependent drag, yaw drag, lift, Magnus force, overturning and spin damping moments — configurable as a constant, curve function, or lookup table.
• Environment: Temperature, pressure, gravity, and 3D wind — configurable as a constant, altitude profile, or spatial field.
• Frame of Reference: Local Cartesian, X-east, Y-north, Z-up.

The trajectory model closely follows STANAG 4355 and McCoy's Modern Exterior Ballistics as primary technical references.

Python

Install

pip install openballistics

Example

import numpy as np
import openballistics as ob

solver = ob.Ballistics(
    model="pm",
    integrator="rk45",
    environment="isa",
    projectile=ob.Projectile(mass=0.1, diameter=0.02, drag_force_coefficient=0.2),
)

def jet(t: float):
    return np.array([
        69.0 + 340.0 * t,
        420.0 + 1000.0 * np.sin(0.5 * t),
        1000.0 + 200.0 * np.cos(0.5 * t),
    ])

solution = solver.solve_launch_direction_and_time_of_flight(
    launch_position=[0.0, 0.0, 0.0], # z is up
    max_time_of_flight=67.0,
    muzzle_velocity=900.0,
    target_position=jet,
)

if not solution:
    print("No valid firing solution found.")
    exit(1)

direction, tof = solution
impact_pos = solver.compute_final_position(
    launch_position=[0.0, 0.0, 0.0],
    launch_direction=direction,
    muzzle_velocity=900.0,
    time_of_flight=tof,
)

np.set_printoptions(precision=3, suppress=True)
print(f"Launch Direction: {direction}")
print(f"Time of Flight  : {tof:.3f} s")
print(f"Bullet Intercept: {impact_pos} m")
print(f"Miss Distance   : {np.linalg.norm(impact_pos - jet(tof)):.3f} m")

Launch Direction: [0.61  0.643 0.464]
Time of Flight  : 3.666 s
Bullet Intercept: [1315.367 1385.849  948.179] m
Miss Distance   : 0.000 m

Contributors

License

MIT © Ariyudo Pertama