The tar monster: creating a character with fluid simulation

Creating the Tar Monster in Scooby Doo 2 presented a unique challenge, because the desired effect of a continually flowing textured character with expressive features had never been done before. Starting from a fluid simulator as in [Enright et al. 2002], we developed the liquid skin technique which applies a fluid layer over an animated character. In addition, the facial animation was preserved by using localized morphing, whereby a specified portion of the simulation is made to match the Tar Monster geometry. The result is a character from whom fluid constantly emanates, with texture sliding down its body and fluid splashing during vigorous arm gestures. Similar previous work includes [Sumner et al. 2003], where the “TX” character is gradually liquefied. Our method, while producing a comparable result in that texture is applied to fluid flow on a character, uses quantities defined over the volume rather than particles for control and texture coordinates.