Rendering has meanings such as “to give,” “to make into a state,” and “to express,” and it is not a term limited to the field of computer graphics. It is also used in various contexts, such as sound rendering, video rendering, and web page rendering. Rendering can be thought of as expressing or transforming original data into a different state or format. In this chapter, we will explain the rendering process of generating 2D images from 3D information that describes synthetic scenes. In particular, we will focus on the intensity calculation of synthetic objects, beginning with the input information required for the calculation. We will cover global illumination techniques used to generate photorealistic images and precomputation-based methods for fast rendering. Furthermore, we will explain the rendering of light scattering effects to enhance realism. Finally, we will briefly introduce advanced rendering techniques.