extrareading.txt

If you'd like to read about some collision topics, here are some links:
(some can be found in the README.txt document)

A Real-Time Physics Simulator for Jenga
https://iypt.ru/wp-content/uploads/2019/08/A-Real-Time-Physics-Simulator-for-Jenga%E2%84%A2.pdf
Paper discussing collision detection, resolution, engines, and an alternative to resting contacts.

Designing with Physics: Bend the Physics Engine to Your Will
https://gdcvault.com/play/1021921/Designing-with-Physics-Bend-the
Talk by Bennett Foddy about collision detection, resolution, mass ratios, and constraints of engines.

MyPhysicsLab
https://www.myphysicslab.com/index-en.html
A ton of different physics simulations to play with, often having the logic and math explained below.

Github Issues Thread on Complementary Problem solvers (LCPs, MCPs, MLCPs, etc)
https://github.com/RobotLocomotion/drake/issues/1772
A long discussion on various solvers for Complementary Problems. Geometric Tool's implementation of
Lemke's algorithm was enough for this use case, but this source lists quite a few more solvers.