All the "realistic" graphics engines are developed by large teams of developers. If you want to work on the Unreal, Unity, Frostbite, CryEngine, Source engine, or similar engines, you should study the available technology, and learn how it works, and then learn how to extend it in some interesting way. You can then use that as a demo/calling card for applying to work on those teams. And, believe me, good graphics programmers are REALLY HARD to find, so if you're good, you'll very likely get a job.
The Unreal Engine requires a simple (free) sign-up, and then you can download and build it yourself on your machine, with full source code. This is a great way of learning how a modern game engine works (with animated meshes, materials, lights, shadows, and all the rest.) If you then want to try something else, all the art path bits (how to import textures, how to animate meshes, and so forth) is already there, and you only need to replace the bits you think you can do differently.