VFX used in ‘I Am Legend’

The biggest challenge was simply entering into a production that had suddenly been fast-tracked. The team didn’t benefit of the normal pre-production and development lead-time needed for this type of vfx work involving creature design. “The project was green-lit without a completed script and, as a result, without a fully-fleshed out concept of what the creatures should be,” Sirrs observes. “We found ourselves still redesigning creatures during post-production to match the continually evolving nature of the film — obviously not an ideal place to be at the same time as trying to get finished shots out of the door.”During principal photography, the vfx approach dramatically evolved. Originally, the creatures — called the Infected — were to be created via prosthetic make-up effects. But due to a lack of development time, the finished make-up didn’t correspond to Lawrence’s vision. As a result, the director chose to cancel the make-up effects effort and switch entirely to CG animation — a decision that obviously had a huge impact on Imageworks’ schedule and resources. “Primarily, the switch was related to the fast-track nature of the project mentioned above,” Sirrs comments. “The original plan was to use digital creatures only for wider shots, in large numbers or for impossible stunts. However, even with juggling the production schedule around, it become apparent that we would begin shooting the creature scenes before the creatures themselves were fully designed and suitable prosthetics created for the actors. There was an attempt to simplify the look/concept of the creatures to keep in line with the original plan, but this ultimately proved to be visually unsatisfactory. Which left us with the digital option — make all the creatures digital and buy ourselves time to finish designing, without impacting the production schedule. Easier to say than do from a vfx perspective, but really the only option that made sense when looking at the production as a whole. And, on the plus side, it freed us up to design the aspects of the creatures that would have been difficult or impossible to do practically.”