Getting started with coordinate systems

Like many files, most model files are binary files. When a game engine, such as Unity, needs to render a model, the data of the model, such as the vertex array of the model and the index of the vertex array, will be extracted and processed through the render pipeline of the game engine.

Note

You can find more information about the render pipeline in computer graphics at https://www.khronos.org/opengl/wiki/Rendering_Pipeline_Overview.

A graphics render pipeline mainly includes two functions: one to convert the 3D coordinates of an object into 2D coordinates in the screen space and the other to color each pixel of the screen. Finally, the 3D model is rendered on the 2D screen.

In the process of the render pipeline, a lot of coordinate system conversion work will be involved, as you can see in Figure 7.1. So, it's an important topic and we will introduce information about coordinate systems in this section:

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