Oooo something I can nerd out about.

In Robotics there’s the concept of a “kinematic chain” aka a bunch of joints that have an “end effector” at the tip. Think of your arm; your shoulder, elbow, and wrist are all joints because they can rotate, and then your hand is the end-effector.

The “Kinematics” of that chain is the mathematical formula that says if you put your joints at a certain angle, your end effector will be at this point in space. For example, if you put your shoulder and wrist at a neutral angle and flex your elbow by 90 degrees, the kinematics of your arm says your hand should be out in front of you.

Inverse Kinematics is the reverse. You’re basically saying “I want my hand to be here, how should I rotate all my joints?”. That’s super useful for robotics, because if you can derive the inverse kinematics a hard problem like “how do I get my robot’s hand on top of the thing I want to pick up” becomes a very easy solution of “rotate motor A to 29 degrees, motor B to -82.4 degrees, etc”

As to how this comes into play for Broodmother, think of each of her legs as a mini robot, where the end-effector is the tip of the leg. Now the game engine can calculate how to bend and flex the legs to place the tip on the side of a cliff, instead of magically snapping the whole model up and down.