Why does the game consist of minimal triangles?

The smallest unit that makes up the game screen is a square dot called " pixel ", but the game using the 3DCG model is also formed by a myriad of extremely small triangles ( polygons ) other than this and why Vox explains whether triangles rather than squares like pixels are used.

Why video games are made of tiny triangles - YouTube


The screen that plays the open world action game " Red Dead Redemption 2 " released in 2018 is displayed, and the narration of "This is a wonderful action adventure game with more than 60 hours of play time" flows.

During the game you can also brush a horse, which makes the real expression that the dust is dancing is a game of Uri.

As in Red Dead Redemption 2, recent years' games have been given extremely detailed expressions up to every detail.

There are many popular games such as Fort Knight, PUBG, Rocket League ... ...

Each has a common point that it has thousands and tens of thousands of small triangles.

This triangle is a character in the game ... ...

It creates the whole field in the car and even in the game. However, innumerable small triangles that exist in the game can not be confirmed simply by playing the game normally. What is worrisome is that, "Why are triangles?"

I will go back to the Red Dead Redemption 2 game screen once more. Technically speaking, everything visible on the game screen is "square". To put it more precisely, all the game screens are made up of "pixels", and each pixel is an accurate representation of only one color. "Pixels constitute the game screen" is like an immutable rule in the game that has been constantly changing from the initial game.

For example, Pon which appeared in 1972 is expressed by connecting pixels. "It was just a square, two paddles and one ball were represented with the squares, and the fact that I move something and move according to it is felt like a very beautiful one "Brett Bibby, an engineer who develops the Unity engine, which is one of the most used game engines in the world, says.

A game engine like Unity is an integrated development environment that games developers have tools that can be used to build complex game environments.

For example, when you think that you want to create a field that will be the stage of Western play.

It is possible to start expressing the halls and banks just by making some boxes.

Bibby who connects cubes and quickly creates what looks like a field.

Regarding the task of building fields of such games, Bibby says, "It's like Lego, it's just like adding sense to the space, repeating this work and slowly developing it I will go forward. "

The 3DCG model so created must be displayed as pixels on the game screen. The process necessary for that is "rendering".

And for rendering, gaming machines and PCs have to perform a large number of mathematical tasks. In the past 20 years the number of pixels that can be displayed on the screen in one second continues to increase.

What is written as "GFLOPS" in the graph below is a standard measure showing the computing capacity of a computer, and it tells the number of calculations that can be executed every second. Since 'G' indicates virion (1 billion), it is likely to convey how many calculations are performed every second.

In other words, using a more powerful computer makes game rendering easier. Of course, game makers continue not only to rely on the performance of computers but also to devise more detailed expressions within the latest technology.

Therefore, in a game engine like Unity, it is required to minimize the number of calculations required to render a model such as a precise field, person, or car created. Triangle is what becomes important there.

A triangle is a way for a game engine to batch process pixels and is used to "perform more detailed processing on a computer".

From the computer's point of view, all of the processing done in the game ......

It is only an enumeration of such numbers. The game engine creates a series of instructions for the computer to convert 3DCG model to pixel.

"V" in the list of numbers processed by the computer means "vertices" and is the "point coordinates" that shape some form.

Imagine building a picture by connecting dots. If you do not know what shape you are making, it is common to connect points and dots with straight lines.

In the case of games, the computer creates solids by connecting points and points while performing thousands of processing per second. Therefore, it is not a straight line but a plane that connects points.

The game engine converts an object made as a curved surface to a plane so that rendering processing on each player 's computer or game machine is simplified.

And it seems that the best way to convert a curved surface to a flat surface is to use a triangle.

If you choose any three points in the space in front of you, whichever point you choose, the triangle consisting of three points constitutes a similar plane. However, it does not work with other shapes with vertices. For example, if there are four vertices, not only a rectangle but also a triangle like a pyramid will be able to be represented. Then mathematical calculation processing becomes more complicated, so even just grasping the number of pixels on the surface will require higher processing capability.

In other words, in order to process a 3D CG model rendered in a game with a smaller number of calculations, it is most efficient to express points by triangles.

With continued evolution of triangles and game technology, "Vox said game developers can develop more beautiful game screens".