The cloud node was my first attempt at writing an Irrlicht ISceneNode, it was also my first real attempt at writing my own C++ classes too, I hadn’t RTFM at the time either so the code is a bit sloppy, but the effect is still good.
The idea is that clouds are made of millions of particles, far more than you could ever draw at once on a low end machine. I decided to make a cloud node which draws only the bare minimum of quads and recursively adds additional levels of detail as you approach it, kind of like a fractal. It does have a maximum depth level which is usually set to a sensible value.
The code for CCloudSceneNode is available from IrrExt’s SVN repository, or see a video of it in action below: