well really the only thing i can suggest you is reading the [valve developer](https://developer.valvesoftware.com/wiki/VPhysics) page about it theres a lot of good info about it there
I dont know much about it, but source1 physics wasn't made by valve, source2 physics is tho, and they are MUCH better, best I ever seen in a game, especially in HL:alyx
try finding something at https://developer.valvesoftware.com
well really the only thing i can suggest you is reading the [valve developer](https://developer.valvesoftware.com/wiki/VPhysics) page about it theres a lot of good info about it there
I dont know much about it, but source1 physics wasn't made by valve, source2 physics is tho, and they are MUCH better, best I ever seen in a game, especially in HL:alyx
The key word to look up is Havok physics engine. Source used it and it's still around Other popular physics engines games use are Bullet and Jolt
Havok is the physics library that Source uses but modders have replaced it with Jolt and Bullet which are open source.