The All Spark Cube is the largest 3D LED cube made by hobbyists. Containing exactly 4096 tricolor LEDs, it is able to produce over 256 colors at 60hz.
Adaptive Computing, the company that creates software that runs on super computers, commissioned several employees and volunteers to spend the summer designing and creating the cube. It is used at trade shows to visually demonstrate how their software can intelligently orchestrate node access in large linux clusters.
There are 2 revisions of hardware.
Revision 1 used 16 arduino megas (1 per panel) to drive each led. It worked well but had limitations in framerate.
Revision 2 currently uses 4 fpga accelerators to drive 4 panels each, and is able to produce over 60 fps
The cube is controlled using a client / server application written in python. It uses thrift to send color commands over standard tcp protocols to a small computer running linux. The computer then connects to the fpga over usb to control the LEDs.
Using this thrift API it's possible to refresh the entire cube in a single API call, or just select certain LEDs to change. For example, one might clear the entire cube before starting a new animation, or they may just update a few LEDs to update an already running animation.