1) Environment Artist
3D Environment Artists are 3D Modelers who specialize in creating indoor and outdoor settings for films or video games.
They are responsible for background visuals with which characters and objects will interact, such as buildings, roads, flora, furniture, drapes, etc.
For films or TV shows, environments are often built digitally when it is not possible or practical to film in real life (e.g. outer space, historical recreations, fantasy lands). Actors may be recorded against a green screen and their surroundings replaced by computer-generated environments built by 3D Environment Artists.
In video games, these virtual environments have an additional layer of complexity. They must function and react according to the laws of physics and within the rules of the game universe. So characters must not be able to walk through walls, objects must react to gravity, etc (unless these are unique features of the game universe).
2) Look Development Artist
Look Development Artis is part of the pre-production phase where a show or movie’s overall artistic & scene styles are established.
In this process, an artist may decide if the look will be realistic, stylized, or both. Flashy or minimalist. Festive or bleak. But this is not exactly the full scope of look development. Those kinds of questions are typically answered during a pitch meeting and involve a lot of higher-ups to decide the “big picture” of the design. Look development is done during very early production by asking the question of how stylized, flashy etc. the final design should be.
For instance, Brave(Pixar) and Cloudy with a Chance of Meatballs(Sony Picture Animations) are both stylized animations but differ heavily in execution.
You can effectively tell each movie apart if you compare their animation styles and how the lighting, colour schemes, and all that other stuff lines up.
A common misconception for look development is to make everything appealing and cute. While that is desirable in animation, it is not uncommon that a well-made prop is removed or revised if it does not fit a scene.
3) Lighting Artist
A 3D Lighting Artist is a member of a larger team of 3D artists who specialize in lighting the final scene(or render) in a style that blends properly with the 3D project. This can include lighting for video games, movies, instruction videos, or architecture mockups.
Once productions reach a certain size, the level of quality and short deadlines makes it infeasible to hire only 3D generalists to produce full projects.
At this point, studios tend to diversify their CG workforce into separate branches.
These branches usually include(but aren’t limited to) dedicated modellers, riggers, animators, texture artists, and lighting artists.
A 3D Lighting Artist will have knowledge of all kinds of lights (or their equivalent in whichever software they use). And most lighting artists develop a professional process in deciding when to use them to their full potential to light their scenes to the specifications of any 3D project.
Light artists will also pair this information with knowledge about lighting set-ups in real-world areas to create a similarly realistic to the scene to whatever they are working on.
These two things, combined with many hours of practice, make a specialized lighting artist incredibly valuable beyond just a general 3D/CG artist.