1.1 What is modelling?

Example: Games

“Many games consist of characters moving in a world where the laws of nature may be slightly different, but similar to those in this universe. These characters jump, walk, crawl, slide, throw, shoot, ride, glide, and fly just like we do. By pressing buttons or turning game sticks, the character performs at will of the player. This happens in an iterative process that is actually no more than a large fictional model with real-time input.

A good example of this is the action of jumping: the player presses a button and the vertical speed of the game character increases. How? Pressing the button causes a change in the value for the force in the y-direction. As known, this causes acceleration, change of velocity, and change of position. This involves a number of variables such as the mass of the character, the size of the friction, the magnitude of the acceleration, and so on. Adjusting these values causes a change in the velocity and height of the jump, which are crucial for the gameplay. The programming of movements therefore consists for a large part of applying the same models as those treated in high school in physics lessons.

Luckily a programmer does not have to do everything himself, because so-called ‘engines’ have been developed through the years, which carry out a large part of the calculations at the background. Within these engines is often a ‘physics engine’, which is actually a huge simulator that performs complex calculations. One can imagine that, for example, with a splintering piece of wood it is almost impossible to simulate the movement of all loose pieces. The physics engine has an algorithm for this. The programmer can set various parameters to render the wood splinters as realistic as possible. To be able to use these parameters efficiently, understanding of how the engine works is indispensable. The basis for this is understanding how modelling is applied in physics.”

Sven Boers, Game developer at Sneaky Mammoth