Exploring the basic concepts of rendering, rasterization, and shading

Rendering is a process that takes 3D data models of the world around our camera as input and output images. It is an approximation to the physical process where images are formed in our camera in the real world. Typically, the 3D data models are meshes. In this case, rendering is usually done using ray tracing:

Figure 2.1: Rendering by ray tracing (rays are generated from camera origins and go through the image pixels for finding relevant mesh faces)

An example of ray tracing processing is shown in Figure 2.1. In the example, the world model contains one 3D sphere, which is represented by a mesh model. To form the image of the 3D sphere, for each image pixel, we generate one ray, starting from the camera origin and going through the image pixel. If one ray intersects with one mesh face, then we know the mesh face can project its color to the image pixel. We also need to trace the depth of...