Fantasia/2000: Blending Art and Technology

Fantasia/2000: Blending Art and Technology
(Continued from page 1)

Fantasia/2000 makes the whale's wonderous water world a reality. © Disney Enterprises Inc.

What a Whale of a Job!
The "Pines of Rome" segment combines CG whales and water surfaces with traditionally animated water, backgrounds and other effects elements. Blending the CG water surfaces with hand-painted backgrounds proved to be visually challenging.

Susan Thayer and Umakanth Thumrugoti came up with the idea of using a color modeling software tool for defining the color of the water surface. The art director would have one window with an image of the water surface, a second window with a curve in 3D space and a third window with red, green and blue sliders. The curve is used in the Renderman shader to assign a specific color to the water surface. This was implemented by Uma and Sergi Sagas.

The first CV (control vertices) on the curve relates to the closest point of the water surface and the last CV relates to the furthest point of the water surface. The X, Y and Z values of the CVs represent the red, green and blue colors. By moving the CVs on the curve, the art director can change the red, green and blue values of the associated point on the water surface. Alternately, one can assign a specific color to the water surface by adjusting the sliders in the third window. There is an immediate feedback in the image of the water surface with the new colors. Once the desired colors are assigned to the water surface, the application generates a curve that is used in the Renderman shader for defining the color of the water surface.

As a side note, Susan Thayer invented the water surface as a spring/mass mesh that was animated dynamically. When the whales break through the water surface, along the elliptical curve of the intersection between whales and the water surface, particles are generated and are given an initial velocity in the direction of the normal to the curve. The particle generation is adjusted in such a way that there are rings of particles formed around the intersection curves which expand in size as they radiate out. These particles were rendered and used as displacement maps in the shader for the water surface.

Note the Water...
In "Pomp and Circumstance," the director Francis Glebis wished to create a massive ocean storm. The desire was to create the impression of a realistic ocean surface, complete with blowing spray and a translucent quality.

The director pointed to various artists' paintings, including the marine paintings of Carl G. Evers. Normally in a traditionally animated film the ocean surface would be animated by hand, similar to the whale sequence in Pinnochio or the water animation in Fantasia's "The Sorcerer's Apprentice." Our main difficulty with this method was the inability to create the translucent look associated with a realistic water surface and yet, still have it blend in with the traditional look of this piece.

The solution was to paint the water surface exactly as the director wanted and then morph the paintings to create the animation.