Just move your mouse in the box below and you'll see the shading change. Your mouse simulates the sun.
Like the sphere WebGL demo, the shaders in this demo have been slightly edited, because WebGL uses different coordinate systems and precision modifiers have been added. You can use the WebGL version, or the original shader files (on the previous page). The WebGL version is also public domain.
Tested under Firefox 25, don't know if any other browser works.