Physics Simulation Morten Paluteder

What is physics simulation?

● Imitate the laws of reality ● Computer animation, film, industrial design, video games, science

The physics

● Mechanics ● Kinematics & kinetics ● Newton's laws of motion ● Forces, force fields, friction

Physics engine

● Middle man between hardware and software ● Real-time vs high-precision ● Scientific engines ● Game engines

Rigid body

● All the bodies that are not deformable ● Resistant body ● Translation, rotation

Rigid body collisions

● Different implementations ● Rigid body as a set of particles ● Detect particles collision ● When two particles collide, apply force

Soft body

● Deformable objects ● Maintain some kind of shape ● Multiple methods ● Simulate cloth ● Fracture, cutting, tearing ● Collisions – discrete, continuous

Crashes

PhysX

● Owned by Nvidia ● Free SDK on Windows ● Physic Processing Unit (PPU) ● Unreal Engine, Unity, Torque

● PhysX Flex

Havok

● Owned by Intel ● Over 500 titles ● Second life

PhysX vs Havok

● The big two ● Havok a bit more on consoles ● PhysX free on Windows

Bullet

● Free and open source ● Collision detection, rigid and soft body dynamics ● 15 games (GTA4&5) ● 10 Hollywood movies ● Blender, Poser and other 3D tools

Bullet Physics in Blender

Ragdoll physics

● Series of animations ● Death sequences, falling ● Gameplay element

Bunnyhopping

● Originates from Quake Engine ● Unnaturally fast movement ● Air strafing ● Quake acceleration & friction ● Competitiveness

More

Adventure of a ball Flappy Bird Cabbage Frozen Snow

Links & References

David M. Bourg, Bryan Bywalec 2013: Physics for Game Developers, 2nd edition GPU Gems 3 https://flafla2.github.io/2015/02/14/bunnyhop.html