Ballistics

Welcome to our first deep dive: Ballistics in Bellum!

Bellum is focused on delivering an uncompromisingly realistic combat experience. To do that, our ballistics system has undergone a major overhaul to bring it even closer to real-world behavior. In this article, we will dive deeper into the game’s physics.

What Makes Our Ballistics System Unique?

Unliked many shooters on the market, our ballistics system is designed to closely replicate real-world projectile physics. Instead of bullets simply hitting targets, they realistically travel through space affected by gravity, air resistance, and velocity drop-off over distance.

• Bullets are affected by gravity, air density, drag, and velocity drop-off over time.
• Every round travels through space with its own calculated flight path, not just raycast hits.
• The system accounts for time-of-flight, with interpolation between frames. This ensures smooth and accurate physics regardless of frame rate.

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All of this creates a level of weapon handling that rewards players who pay attention to detail, especially in longer battles and extreme conditions.

Penetration and Ricochets

One of the areas we’ve put a lot of work into is how rounds interact with surfaces and materials. When a bullet strikes a surface, we look at:

• Material type and density (wood, metal, concrete, etc)
• Thickness
• Impact angle
• Bullet energy and composition

So, if you’re firing 5.56 into drywall, you can expect it to go through and potentially hit enemies behind. Try that on thick steel or reinforced concrete at the wrong angle, and it might bounce right off or get stopped entirely.

Ricochets are determined by angle, surface hardness, and retained energy. We also calculate how much energy a round keeps after it bounces, and yes, ricochets can still kill.

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Body & Armor modeling

For armor and body damage, we simulate penetration based on multiple factors.

• Armor type and material strength
• Thickness
• Round type (FMJ, AP, frangible, etc)
• Angle and impact velocity

If the round hits soft body tissue, we use layered interaction logic to determine penetration depth and potential blunt trauma. Armor, alongside stopping bullets, can deflect them depending on where you’re hit and what you’re being shot with.

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We’re also planning more advanced modeling later down the line, like:

• Entry and exit wound behavior
• Spalling from armor plates
• Bone deflection
• Hydrostatic shock
• Internal trauma effects

Atmospherics

Our ballistics system also incorporates environmental factors that impact every single shot. We are actively developing systems that make condictions (like in the real world) affect bullet performance on the fly.

Wind

Right now, wind is in development. We’re building it as a spatial vector system that includes vertical and horizontal movement, gusts, and even terrain-induced channeling. So if you’re shooting in a valley or over a ridge, it’ll count

Temperature and Air Pressure

These both affect bullet drag and performance. High pressure leads to denser air, which leads to more drag and in return leads to velocity loss.

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Colder temperature also increase drag by increasing air density. These changes are calculated live in-game and will affect drop and range.

Humidity

Humidity isn’t modeled yet, but it’s something we’ve talked about adding in future iterations.

Extreme Conditions

Shooting from high altitude? Firing at a steep angle? Fighting during a hurricane in-game? All of those factors affect your shot. We keep results physically consistent, even in edge cases.

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Ammo Calibers & Performance Differences

Every ammo type in Bellum has its own behavior. Two bullets of the same caliber won’t always perform the same, because we model:

• Bullet mass
• Core material (lead, steel, tungsten, etc.)
• Shape and drag profile
• Muzzle velocity
• Penetrators and fragmentation potential

So firing a standard 7.62x39 FMJ and a high-velocity AP round will give very different results, both in penetration and how the round flies. Ammo matters.

How It Compares

While other games do emphasize realism, their ballistics systems simplify other aspects for gameplay or technical reasons. Our system pushes the engagement further by factoring in nuanced bullet physics and material-based interactions to bring a more authentic feel to every round you play.

What’s Next?

We will continue to refine the system based on both internal and feedback from our community. Future updates will expand upon our system, wound modeling, internal damage reactions, advanced ballistics under extreme weather, and more.

We also have some exciting new developments and features on the way so stay tuned for those.

We appreciate your ongoing support and feedback as we continue evolving Bellum, and as always, be sure to follow our news channel for the latest updates, and join the conversation over on our Discord.

-The Bellum Team