The guinea pigs look and move so realistically. How was that achieved?
The directing duo, Neo, were very certain about the style they wanted to achieve. The guinea pigs had to look like real guinea pigs, but with human characteristics-and the viewer had to be comfortable about the fact that they were watching small animals in a model world. To achieve the brief, we dealt with the two main issues separately. To have the guinea pigs act in a more human environment-shopping malls, taxis and in the street-actors were dressed in oversized guinea pig costumes and shot on location, which formed the body elements. Real guinea pigs were then shot on greenscreen, dressed with green collars, and sections from this footage were matched to the body action. Once the heads approximately matched the bodies, time was spent retiming, tracking and keying the heads so as to make the blend and movement as seamless as possible.
What was the most difficult effect to pull off?
The marriage of the guinea pigs heads to the human bodies was a large focus for us-if that didn't work, the commercial wouldn't have the right message. The styling of the bodies by the directors, agency and art department helped immensely. Adding the real heads successfully was then down to a mixture of compositing techniques-adding extra fur, retiming movement, stabilizing and retracking, and adding additional shadows and lighting. Some detail in the real-world locations had to be removed and replaced with model detail that matched the guinea pigs' scale, further enhancing the illusion.
What other techniques did you use to make the settings more realistic?
We built many of the city models that appear in the laboratory using 3D Studio Max, and all the real exteriors and props had to be simplified to achieve a more model-like environment for the guinea pig test world. Stills of toy trees and model cars were used to strip in fake detail, and a shallow depth of field effect applied to the model world, thus enhancing its smallness.