Ragdoll Physics in Video Games

I remember first becoming fascinated with physics when I went to Six Flags Great America back in 8th grade. I remember waiting in line for this one rotational cart ride with my one friend, and we began talking about how all these roller-coasters and rides supposedly "worked".  This one old man heard our conversation, turned around, looked us in the eye and screamed "You gotta use physics!" That was my starting point

Anyway, I am currently interested in getting some kind of degree in Physics at UW-Madison because I love to think of all the applications involved in video games and simulations! I am currently reading John Taylor's Classical Mechanics.

I discovered that many games rely on a Physics-based, computer animation technique called  Ragdoll Physics.

One important thing to mention before discussing more on physics is the idea of animation. More recent Game engines (from the late-1990's to present day) utilize a skeletal system for their characters, where the animators create, place, and link "bones" on their characters that can be posed and constrained. These bones are joined together in such a way that the animators can create animations by moving/rotating these bones individually while recording an animation. This mathematical process uses the kinematic equations to find the joint angles between interconnected segments (bones) and the pose/configuration among these bones; this is called "Inverse Kinematics." I haven't yet learned the mathematical formulations for inverse kinematics, although I will definitely touch up on this again in the future! It involves Jacobians!

Ragdoll Physics is a type of physics system that utilizes "Procedural Animations", which are real-time, generated animations of characters in a gaming world that are played when objects interact with their skeletal structure. For example, if the player gets hit by a ball, the player's character may animate (or respond) differently each time the ball is thrown at him/her. This is incredibly useful because it sometimes allows developers to eliminate tons of predefined animation sequences that are hard-coded into the game and that are often repeated again and again. Ragdoll physics offers more animation diversity!

Here is a Wikipedia article on Ragdoll physics if people are interested, or if you like Wikipedia. I love watching the videos/simulations that Wikipedia users provide, and this is definitely an interesting page. It links to other kinds of topics too.

https://en.wikipedia.org/wiki/Ragdoll_physics

Here is a short video on the history of Ragdoll Physics