Collidable Representation


Poly Soup

Sphere intersection test

Sphere intersecting other sphere test

Separating axis theorem

GJK Algorithm

Paper Bullet Problem (Tunneling)

Performance Optimizations

Collision Queries


Shape Casting


Collision Filtering

Collision Materials

Ordinary Differential Equations (ODEs)

Common ODE methods

Plastic vs. Elastic Collisions

Newton's law of restitutaion for instantaneous collisions with no friction

Penalty Forces

Coming to Rest


Torque and Force


The collision/physics step

Updates every frame:

  1. Forces and Torques integrated by time step Δt
  2. Collision Detection library checks for new contact
  3. Resolve/Handle Collisions
  4. Constraints Resolved by the Constraint Solver

Attaching physics to a game object

Game Object Diagram

Game-Driven vs. Physics-Driven


Powered Constraint

Rag Dolls

Fixed Bodies

Physics Simulation Update Frame Steps

Bullet Ray Casting / Bullet Traces

Collision vs. Visible Geometry


Destructable Objects

Camera collision

Some tricks/things to keep in mind when implementing a third person camera, to avoid the camera hitting things or going inside things

Current Areas of research for physics in games