by being able to model things, you'd already set yourself apart from the endless stream of artists running our of school each year. you wouldn't believe the amount of applications we reject, simply because people are too addicted to zbrush.
Essentially the same as what you can do in Maya and 3ds Max where you can render out the floor shadow separately? I believe, the last time I did it, you're able to toggle the model off so only the shadow is seen? It's just to make it easier to composite everything together in Photoshop. Ideally with renders from Marmoset…