A Technique for Art Direction of Physically Based Fire Simulation

Abstract

This paper presents a new approach to the art direction of individual flames in a physically based fire simulation. Fire, due to its warm colors and constant movement, often becomes the main attraction to the viewer's eye in a scene. Therefore, being able to control a fire simulation to obtain a desired look or shape is crucial if simulation is to be used to create a fire effect. Our technique provides control over this chaotic natural phenomenon at a fine level, enabling the artist to add character to flames and create highly stylized visuals. The fire system itself is a fully physics-based two-gas system, where flames are advected along convection currents generated by combustion. Our method provides artistic control of these convection currents, using a set of imported curves drawn by an artist. A full description of the implementation and performance of the fire system, and our control method is presented. The technique is illustrated with examples of highly stylized flame artwork rendered using our system.