PHYSICS SIMULATION IN 3D

GAMES

An Introduction to Physics Engines

Michael SundqivstTV10S1M3

Overview – what is a physics engine?

Collision types Rigid body dynamics Soft body dynamics Fluid dynamics Views for the future Summary

What is a physics engine? Simulates real-world physics Knows generally about physics but

isn’t pre-programmed for any game

Advantages:Saves timeQuality of animation

Weaknesses:Processor usageToo big for certain projectsScope

Collision types

Two methods of detecting collisions:

Bounding-box:Two meshes, one for viewing and one

for calculating physics (collision geometry)

Broad phase collision detection Finite-element:

3-dimensional volumetric tesselationUsed by a solver to model stress

Rigid Body Dynamics

Solid, non-deformable object Enables rolling physics Forces that affect movement:

Gravity – falling speedMass – force required to move the

object

Examples: rolling balls, solid items http://www.youtube.com/watch?v=

MNhDCk2rD0Y

Soft Body Dynamics

Physical simulation of deformable objects

Tries to contain original shape (unlike fluids)

Generally only visually plausible emulations

Uses: destructible materials, plasticity and melting, hair, fur, simulated organs

http://www.youtube.com/watch?v=qdusMZlBbQ4

Fluid Dynamics

Interaction of liquids and gases with surfaces defined by boundary conditions

Made of numerous particles, usually acting within a grid

Common uses: liquids, smoke, fire, explosions, gases

http://www.youtube.com/watch?v=x_IwYVLNiOs

Views for the future

More processing power = better quality

Even more realistic engines Growing usage on mobile devices Visually stunning games