Game physics

Computer animation physics or game physics involves the introduction of the laws of physics into a simulation or game engine, particularly in 3D computer graphics, for the purpose of making the effects appear more real to the observer. Typically, simulation physics is only a close approximation to real physics, and computation is performed using discrete values.

There are several elements that form components of simulation physics:

• Physics engine is program code that is used to simulate Newtonian physics within the environment.
• Collision detection is used to solve the problem of determining when any two or more physical objects in the environment cross each other's path.

Particle systems

For more details on this topic, see Particle system.

A common aspect of computer games that model some type of conflict is the explosion. Early computer games used the simple expediency of repeating the same explosion in each circumstance. However, in the real world an explosion can vary depending on the terrain, altitude of the explosion, and the type of solid bodies being impacted.

Depending on the processing power available, the effects of the explosion can be modeled as the split and shattered components propelled by the expanding gas. This is modeled by means of a particle system simulation. A particle system model allows a variety of other physical phenomena to be simulated, including smoke, moving water, precipitation, and so forth.

The individual particles within the system are modeled using the other elements of the physics simulation rules, with the limitation that the number of particles that can be simulated is restricted by the computing power of the hardware. Thus explosions may need to be modeled as a small set of large particles, rather than the more accurate huge number of fine particles.

Ragdoll physics

For more details on this topic, see Ragdoll physics.

This is a procedural animation and simulation technique to display the movement of a character when killed. It treats the character's body as a series of rigid bones connected together with hinges at the joints. The simulation models what happens to the body as it collapses to the ground.

More sophisticated physics models of creature movement and collision interactions require greater level of computing power and a more accurate simulation of solids, liquids, and hydrodynamics. The modeled articulated systems can then reproduce the effects of skeleton, muscles, tendons, and other physiological components.

Books

• Eberly, David H.; Ken Shoemake (contributor) (2003). Game Physics. Morgan Kaufmann. ISBN 978-1-55860-740-8. 
• Millington, David (2007). Game Physics Engine Development. Morgan Kaufmann. ISBN 978-0123694713. 

See also

• Cartoon physics
• Physics engine
• Physics game

References

External links

• Game physics resources on GameDev.net
• Online Physics Games at Phyfun Games
• Bullet Physics Engine is an open source physics engine free for commercial use, including PlayStation 3.
• DigitalRune Knowledge Base contains a comprehensive list of physics engines and links to game physics resources.