We present a simple, linear 3D cellular automata approach for animating the melting process of solid volumetric models. Accurate modelling of object melting usually requires complicated physical simulations of heat transfer and phase transition from solid to liquid. Instead, we propose a simplified model to describe the melting behaviors of highly viscous objects, such as wax, lava, plastic, metal and chocolate. We simulate the process by which a volumetric solid transforms into a viscous liquid as the amount of heat it accumulates on its surface reaches a certain temperature. We then animate smooth fluid behavior using a cellular automata. The dynamic volume data is rendered directly on texture mapping hardware to achieve an interactive speed.