3D animators create moving images using digital models, or digital environments, depending on their specialty. Some animators focus solely on creating models of humans, animals, and other objects that would appear on the screen and rigging those models, while other 3D animators focus on the environmental aspects that the video needs like backgrounds and background animation like crowds and precipitation. Once the animator has created the 3D models, they polish them with details like textures, hair, skin, etc.
Animators that focus on environmental aspects like land, buildings, and other backgrounds create worlds that can then be utilized similarly to shooting on a set, where the camera follows the characters through this world depending on where the creators want it to go. In addition to looking more realistic than 2D, 3D environments are much easier to scale when it comes to using them in videos and games and pointing a camera in them.
Large projects like feature films and cartoons that may reuse the environments would require substantial world-building on the animator's part, while small projects like commercials may not require as large of a 3D environment that needs to be created and animated.
3D animators must work closely with different people on the video. In addition to working with the director and writer to ensure that their animations are consistent with both of their visions, the animator must also work with voice actors and music directors (depending on the size and budget of the project) when creating animated scenes.
3D animators need to lip-sync character models to voice direction so that the voiceover matches with the model's mouth frames. Depending on how many animators have been brought onto the project, this can be a secondary role. When music directors are also working with the director and animator, characters and environments need to be synced and adjusted according to the director's vision as well as the direction of the music and other audio cues to create a cohesive video.
Rigging the character models is also an important job for 3D animators, if they are working on a small project that didn't hire additional talent to rig the models so that they look more life-like and consistent with the environmental design.