The case when physics is actually fun

Many people spend their free time with playing video games, but most of video games must follow laws of physics and that’s why video games usually must be created by people who know a little bit of physics.

Basic code of any video game in most of cases contains simulations of Newtonian physics within the environment, and collision detection, it solves the problem of determining when any two or more physical objects in the environment cross each other’s path.  A package with such code usually called “physics engine”. It simulate walking or running or driving of characters based on Newton’s laws. In addition, it simulate supporting effects such explosion, or destroying objects around or any other influence on a media by the character.

For example, many video games contain effects like explosion, and realistic simulation of such effects is actually a big challenge for physics engine. Early computer games used the simple expedient of repeating the same explosion in each circumstance. However, in the real life an explosion can be different depending on the terrain, altitude of the explosion, and the type of exploded materials. Nowadays, the effects of the explosion can be modeled as a system of many particles propelled by the expanding gas. A particle system model allows a variety of other physical phenomena to be simulated, including smoke, moving water, precipitation, and so forth.

Picture1
Fig.1 A particle system used to simulate a bomb explosion, created in particleIllusion[1]
Another simulation connected with many particles is simulation of cloth. System of particles and springs based on the Hooke’s law can be used to simulate complex motion of non-rigid materials such as cloth. Fig. 2 illustrates a network of particles and springs that form the basis for a waving flag simulation. Such a flag may appear on top of a castle in an adventure game. Or perhaps the robes of a wizard character would be modelled in this way to achieve a realistic flowing motion as the wizard ran or waved his arms while casting a spell.

Picture2.png
Fig.2 Cloth simulations[2]
Another realistic simulation in games is using a ragdoll physics. One of the applications of this technique can be simulation of death of a character. Early video games used manually created animations for characters’ death sequences. As computers increased in power, it became possible to do limited real-time physical simulations. A ragdoll is a system of multiple rigid bodies connected together by a system of constraints that restrict how the bones may move relative to each other.  The Jurassic Park licensed game Jurassic Park: Trespasser exhibited ragdoll physics in 1998 but received very polarised opinions; most were negative, as the game had a large number of bugs. It was remembered, however, for being a pioneer in video game physics.[3]

All examples discussed above rely on Newton’s laws of motion.  However, sometimes games take into account rules of non-classical (quantum) physics. One of the examples can be Quantum MiniGolf[2]created by one of the our colleagues. In this game a ball can be at several places at once, it can diffract around obstacles and interfere with itself. So, the ball acts as a wavepacket. And it’s a nice example of quantum physics in games.

And there are a lot of other examples of physics in games, like nice gravity simulations in Mario Galaxy series, or cool characters mechanic in Grant Theft Auto series. And thanks to people who work on physics engines we have realistic video gameswhich helps us to immerse deeper into this virtual world.

By Andrii Volkovskyi, PhD student at TU Munich

References:

[1]  https://en.wikipedia.org/wiki/ParticleIllusion

[2] David M Bourg 2004 Phys. Educ. 39 401

[3] Wyckoff, Richard (May 14, 1999). “Postmortem: DreamWorks Interactive’s Trespasser”. Game Developer.

[4] http://quantumminigolf.sourceforge.net

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s