Here are some screenshots of my 3D Engine (codename Metaverse) I made a few years ago (click to enlarge). It is written in Java and uses JOGL (JSR 231) as OpenGL binding and JInput to access the controllers.
These shots show the real time lighting and water rendering capabilities. They also show that you are the whole time on a real 3D planet (codename potato ;) ).
The next shows a 'test vehicle' to test model loading, animation, physics and collision detection of the Engine. You can use this vehicle to discover the planet - it makes even a lot of fun to drive through rough terrain and try to survive jumps from steep hills ;). The other screenshot shows the planet as wireframe.
The last two show the continuous triangulation of the terrain mesh and the space subdivision into a quad-tree (important for fast frustum culling and physics). The viewer is configured to be located inside the river bed.
You think that Java for 3D Graphics is like a penguin in hell? If you follow some rules to prevent stop the world garbage collections (full GCs) and prevent calls through the JNI where possible you can reach with the server (hotspot compiler) JVM performance comparable to C++ code.
The rendering performance is quite good. Even fast fly overs are rendered with 60+ fps (frames per second). If the camera stays still the renderer reaches 200+ fps on my notebook (ATI X1600) .
I have currently no time to continue with this project but if I think back how fun it was to work on that engine I would love to start hacking again immediately ;).