What does Unity3D NOT do for you? What else do I need in the game creation process?

I’m in the process of creating a game, and up until now, I have been working on a project in Java for about a month. I know a good deal of Java, and I’ve gotten everything in my game working up until the 3D modeling implementation of it. I’m learning 3DS Max to create rough 3D models, and I don’t really care if the models look good, as long as I create a working game. I read a lot on the Java 3D API on collision detection, AI, animation, scene graphs, and many other things. At first I was under the impression that I would create 3D models and import them into my Java program, and everything else would be handled with Java coding. I have just discovered Unity 3D and I can see that the whole process will be much simpler with its use, but I’m entirely unsure of my Java codes role in the whole design. I understand that I import models from 3DS Max into my Unity Scene, but I don’t know what comes next. Should all the animations be done in 3DS Max? And what functionality does my Java code play in Unity? In other words, what is Unity’s core function in a game-making process, and what other sections are needed, at the very basic level of a game?
Thank you for your time.

Your java will not do anything in unity, you will be starting again. If you want to do 3d, with shaders, shadows etc then you have no option but use an existing engine like unity. I would get into it, C# is alot nicer IMO and you’ll pick it up instantly coming from java.

Animations are usually made with the model, I use a Mac so I’m not sure about 3dsmax but I export animations as FBX with the model / bones. The Unity animation controllers can take it from there.

I HIGHLY suggest getting into Unity, it will extend your horizon immensely, especially in the 3d department of your game.