See how Dreamworks has developped its charactersof Rise of The Guardians, Sandman from concept art to the final CG animated model.
DreamWorks Animation’s adventure, Rise of the Guardians, has different characters - the Sandman, Jack Frost, Santa Claus, the Tooth Fairy, the Easter Bunny and the evil Boogeyman - had their own unique power and therefore required distinct effects personalities.
Head of Effects Yancy Lindquist Said The Guardian of Dreams, Sandy (the Sandman) does not speak at all during the movie but instead conjures up his thoughts, and dreams, via golden sand objects and ‘sand streams’. These range from dinosaurs, to unicorns, airplanes and candy canes - all needing to be crafted by the effects department.
After some early R&D, the process of creating the sand shapes involved conceptualizing the shapes, then modeling an enclosed version using sub-division surfaces that would phase volumetrically. That would then be filled in with points inside Side Effects Houdini. One particular challenge with the sand shapes arose when the shapes moved into another shape, which the effects team found hard to achieve via fluid simulations alone, and so several techniques were ultimately relied upon.
“For example, in the movie there is a sand unicorn that a child is dreaming about,” notes Lindquist. “That involved binding the points to the deforming unicorn, then when that needed to break apart and start flowing, we’d pull that apart with a combination of particle and fluid simulation. We let the fluid simulation pull it along, and then when we finally get to the other shape we would then use a little bit of particle sim to pull it closer. We’d then do a little trick as the particles get really close where they would start filling in the shape. From that we were able to get sims that felt natural. We even had some flocking simulations in there.”
A number of ‘sand tools’ were developed to help artists achieve the desired look. “The workflow inside Houdini is based around dropping down operators to perform tasks,” explains Lindquist. “We could configure them in different ways to achieve various effects.” The sand effects were rendered in Mantra, with the DreamWorks Animation-developed OpenVDB format relied on to create high resolution sand volumes.