Abstract: We describe an algorithm for rendering animated smoke particle systems in a cartoon style. This style includes outlines and cel-shading. For efficient self-shadowing effects, we introduce nailboard shadow volumes that create complex shadows from few polygons. Including shadows, the renderer draws only three polygons per particle and entirely avoids the latency of depth buffer readback.We combine the renderer with a fast simulator that generates the phenomenology of real smoke but has artistically controllable parameters. Together they produce real-time interactive smoke animations at over 30 fps. Thus our algorithm is well-suited to applications where interactive performance and expressive power are preferred to realism; for example, video games and rapid development of animation.