The rules of physics in video games

Our world is full of surprises. Nevertheless, if we drop an object from the third floor, we expect it to fall down because of gravity and would feel unsettled if we saw it going upwards. We would even imagine being in a totally different world.

The same thing happens in video games. No matter if we are playing in a dystopic or fantasy scenery, we expect even that fictitious world to be affected by the usual reliable rules.

That is why games must have physics in their design, but at which degree? Moreover, is that Newton, quantic, or instead video game physics?


Video game physics: a sense of real

How do sea waves move and smoke rises in the air? What is the effect of inertia on passengers when the train they travel in stops abruptly? Our brains have an expectation of what happens when things fall, collide, or burst into flame, and it is the job of physics programmers to mimic real life as closely as possible. They implement code for systems that describe explosions, determine bullet trajectories, detect collisions, or control flowing fluids.

Another significant concern is the animation of the characters. The programmers use the “ragdoll physics” to simulate what happens to a body – no matter if it belongs to a human being or an unusual living creature – when it hits the ground or is struck by an utmost force. They give characters bones and joints programmed to respond to multiple kinds of impacts and simulate all possible reactions. 


The enhanced physics of video games

We have seen how important it is to include physics elements into the virtual world to give a feel of authenticity, but of course, people do not play video games for realism, do they? The core task of a physics programmer is not to respect physics rules, but to use them to intensify the player’s involvement in the game’s action. Just to give an example, a driving game like Grand Theft Auto wouldn’t be so appealing if the experience of driving in the game reproduced exactly the constraints and rules of driving in real life. In virtual reality, you can have incredibly grippy tires, take turns dangerously fast, even fly over the traffic. 

In this case, physics programmers are writing code that sets new rules with different parameters, but there are still rules. 

Sometimes the fun of video-games relies on augmented physics. Programmers can spice up scenes by juggling with gravity, velocity, trajectory, momentum, and collisions. Some characters can jump really high, and weapons can be incredibly powerful. Different weights in similar objects give unexpected results and need strategic decisions.

Physics in video games should increase the fun, not eliminate it!


What’s a physics programmer good at?

Physics programmers write the code that governs the physics of video game. They create software that describes – among others -what happens when objects crash or collide, or how light rays are reflected. Their work requires strong expertise of both physics and programming, but also a comprehension of games engines and platforms. They must understand the different programming requirements and constraints of games consoles, PCs, handhelds, and mobiles. A taste of gameplay is crucial, too, to imagine what can surprise and entertain the players. And, as usual in creative teams, they must be able to develop innovative systems and share ideas with other members of the production pipeline.