A technical sketch presented in the Feature Creatures session at SIGGRAPH 2004
The Tar Monster
Creating a Character with Fluid Simulation
| Mark Wiebe Frantic Films mwiebe @ franticfilms.com |
Ben Houston Exocortex Technologies, Inc ben @ benhouston3d.com |
|
Overview 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. In addition to using the liquid skin and localized morphing techniques described in this short sketch, we also made use of level set morphing (originally developed by David Breen and Ross Whitaker) in two shots. More information about how the high resolution level set morphing was achieved can be found in the forthcoming ACM Transactions on Graphics paper entitled "Hierarchical RLE Level Set: A Versatile and Compact Level Set Representation." What people are saying about the Tar Monster special effect: "Frantic did an amazing job on very short
order on the Tar Monster... it turned into the biggest and
most involved monster of them all." "We did some tests with other companies
and what [Frantic Films] did in terms of their flow dynamics.
From the get-go, Frantic was so much more impressive than
anybody else. They specifically had such a great grasp
on taking this character and making him as real as can be
in the live action world." "The National Research Council of
Canada has named [Frantic Films] one of Canada's Innovation
Leaders. [...] the honor was bestowed largely because of new
technology developed by Frantic for its FX work on the
Warner Bros. hit sequel Scooby-Doo 2: Monsters Unleashed.
The fluid simulation technology [...] was developed to
create the Tar Monster character by Frantic's R&D team,
including Ben Houston, Mark Wiebe and Christopher Batty. "Based on
[the fluid simulator's] strength, Frantic was able to win
the Tar Monster contract even while competing against the
major U.S.-based studio that was animating other
characters in Scooby Doo II." Related external sites:
Wiebe, M. & B. Houston. (2004) "The Tar Monster: Creating a Character with Fluid Simulation." Proceedings of the SIGGRAPH 2004 Conference on Sketches & Applications. ACM Press. [PDF] (Supplementary Materials [PDF])
@inproceedings{
author = {Mark Wiebe and Ben Houston},
title = {The Tar Monster: Creating a Character with Fluid Simulation},
booktitle = {Proceedings of the SIGGRAPH 2004 Conference on
Sketches \& Applications},
year = {2004},
location = {Los Angeles, California},
publisher = {ACM Press},
}
This research was supported in part by NRC IRAP Grant #482564. |
