Using a Variable Inertia Law (NKTg) for Advanced Motion Simulation in Games

Hi everyone,

I’d like to share a physics-based concept I’ve been working on called the NKTg Law on Varying Inertia, and I’m looking for feedback from fellow game developers and physics enthusiasts.

🧠 What is NKTg Law?

In most game physics systems, inertia is treated as static — we apply forces to a rigidbody of constant mass. But what if mass could vary? And what if the rate of mass change played a role in the motion tendency?

That’s where the NKTg Law comes in. It proposes that the motion behavior of an object is influenced by:

p = m * v NKTg1 = x * p // position × momentum NKTg2 = (dm/dt) * p // mass change × momentum

Where:

• x is position relative to a reference
• v is velocity
• m is mass (possibly changing over time)
• dm/dt is the rate of mass change
• p is linear momentum

🎮 Why This Might Be Useful in Games

In many game genres, such as:

• Space simulators (variable-mass ships, boosters)
• Physics-based sandbox games (like Kerbal Space Program)
• Planetary systems or orbital games
• Boss mechanics that change mass/state over time

...the NKTg quantities can be used to influence or even predict movement tendencies dynamically.

For example:

• If NKTg1 > 0: The object tends to move away from equilibrium.
• If NKTg2 < 0: Mass change resists movement — like drag or fuel depletion.

🧪 Sample Pseudocode:

// Game update loop void updateObject(GameObject& obj, double dt) { double p = obj.mass * obj.velocity; double NKTg1 = obj.position * p; double NKTg2 = obj.massRate * p; // Interpret results (simplified) if (NKTg1 > 0) obj.movementBias = "divergent"; else obj.movementBias = "stable"; if (NKTg2 > 0) obj.massEffect = "supports motion"; else obj.massEffect = "resists motion"; }

This could even be visualized as a dynamic force feedback layer or used for procedural animation / trajectory deviation.

❓ Looking for feedback:

1. Does this approach make sense in a game engine context?
2. Could it be efficiently integrated with existing physics engines like Unity’s Rigidbody or Bullet?
3. Would this be useful in procedural animation or space game mechanics?

I’d love to know if anyone here has worked on something similar — or if this sparks any ideas on how to use varying mass in gameplay or AI.

Thanks for reading!