Here are the key advanced video games physics techniques currently in use:
1. Advanced Collision Detection and Resolution
- Continuous Collision Detection (CCD): Unlike traditional discrete methods that may miss fast-moving objects, CCD calculates potential collisions over time, ensuring high-speed projectiles or fast-moving objects do not pass through walls, a crucial feature for shooters.
- Broad-Phase and Narrow-Phase Optimization: To handle large environments, engines use broad-phase techniques (e.g., Spatial Partitioning, Bounding Volume Hierarchies) to quickly filter out objects that are far apart, followed by narrow-phase, detailed checks only for close objects.
- Separating Axis Theorem (SAT): A mathematical approach to check for collisions between convex shapes, determining if they overlap by checking for a separating axis.
- Finite Element Method (FEM): Used for highly accurate simulation of deformable objects, breaking them into small pieces to calculate structural integrity, stress, and deformation under force.
- Soft-Body Dynamics: Simulates non-rigid, deformable materials like jelly, rubber, or cloth. These methods often involve particle systems, where individual sections of an object are simulated.
- Fluid Dynamics and Particle Systems: Real-time simulations of liquids, gases, smoke, and fire using particle systems. Modern techniques are moving towards high-resolution fluid simulation that allows for interactive, flowing, and splashing water.
- Constraint Solvers: Instead of just calculating forces, constraints (like hinges, ropes, or joints) are solved iteratively (e.g., using relaxation techniques like Gauss-Seidel) to keep objects attached or rigid.
- Ragdoll Physics: A form of procedural animation that replaces static death animations with a realistic, physics-driven simulation of a character's skeleton collapsing and reacting to the environment.
- Inverse Kinematics (IK): A procedural technique to compute the proper orientation of a character's limbs (e.g., feet placing correctly on uneven terrain) based on their interaction with the environment.
- Destruction Physics: Real-time, in-game fracturing of objects (e.g., shattering glass or breaking wooden beams) based on the force and angle of impact.
- GPU Accelerated Physics: Moving physics calculations from the CPU to the GPU (e.g., Nvidia PhysX) allows for thousands of particles or complex soft-body simulations to run in real-time without bottlenecking the main processor.
- Verlet Integration: A numerical integration method that is highly stable and used to calculate the positions of particles in a system, particularly in cloth and ragdoll simulations.
- Memory Pooling: Frequently re-using objects (like bullets or debris) to reduce the overhead of creating and destroying objects during intense action.
- Deep Learning for Physics: Integrating AI into physics engines to predict or approximate complex simulations in real-time, resulting in more adaptive and personalized interactions.
- Quantum Physics Simulations: Early research into incorporating quantum mechanics concepts like entanglement and uncertainty for unique gameplay mechanics.