The art of doing animation is simply transforming vertex positions over time. In this sample, we do this by adjusting the model matrix every single frame. We spawn another thread that periodically calls back to the event dispatch thread to redraw applet. If we can keep a high enough framerate, it results will look smooth. This is rather important, because otherwise, these applets are really no better than static images. In fact, I could probably make a rather convincing argument that they are worse.