Lighting for Realistic Visuals: 3D animation is supposed to feel real or as close to reality as possible, and for that, how you manipulate light in images plays a considerable role. To get the best look and feel out of a 3D animation video, animators and designers have to carefully decide the best lighting settings for each frame, one by one. This requires both skills, and a creative vision to create a visually stunning experience for viewers.
Compositing and Special Fx: The combining of different visual elements from various sources into one place to create the illusion that they are part of the same scene is called compositing. If your 3D animation requires such an effect or any other special visual effect that merges different source files into one image, then it is part of the production process. This includes effects such as explosions and morphing illusions and is mostly done when merging live-actions scenes with digital environments.