Rigidbodies

Rigidbodies are a fundamental concept in physics simulations, particularly in computer graphics and game development. A rigidbody represents a physical object that is assumed to be infinitely stiff, meaning its shape does not deform under stress. In simulations, this translates to objects that have mass, velocity, and are subject to forces and torques. When forces are applied to a rigidbody, they cause it to accelerate linearly and rotate around its center of mass.

The core principle behind rigidbody simulation is the application of Newton's laws of motion. Specifically, the second law, F=ma (Force equals mass times acceleration), governs linear motion, while its rotational counterpart, τ=Iα (Torque equals moment of inertia times angular acceleration), governs rotational motion. Simulation engines typically discretize time into small steps and update the position and orientation of rigidbodies based on the net forces and torques acting upon them during each step.

Collision detection is another critical aspect often paired with rigidbodies. When two rigidbodies collide, forces are generated at the point of contact, which, in turn, influence their subsequent motion. The nature of these forces depends on properties like elasticity and friction, which are often defined for each rigidbody. Without rigidbodies, simulating realistic interactions between objects in a virtual environment would be significantly more complex and computationally expensive.