animals: https://www.ibiblio.org/e-notes/Splines/animation.html
fractal terrain: https://www.ibiblio.org/e-notes/Splines/terra/subdivision2d.htm
fire: https://www.ibiblio.org/e-notes/webgl/models/fire.html
clouds: http://mrdoob.com/lab/javascript/webgl/clouds/