For shots involving the practical A.X.L the puppeteers and their rigs were removed, while accessories such as eye shields, spinning teeth and laser projectors were added. Subtle reworking of expressions and eyeblinks, along with gags like sparks for his “chewing” actions also helped give the puppet life and character.
Like the practical puppet, the CGI dog consisted of hundreds of parts. Some needed to be rigid and pivot as though attached to some underlying mechanics. Other parts such as his neck shields needed to bend and twist. The Cutting Edge artists matched what was observed from the practical shots, but took some creative steps in the robotics design to get the greater range of motion without intersections.
Cutting Edge VFX Supervisor Rangi Sutton explains, “We were cutting between the puppet and our CGI A.X.L., so not only did our movement need to look like it came from the same source, our lighting and materials needed to be spot on or that slight-of-hand would be obvious to the audience.”
With the assistance of Queensland University of Technology and Logemas Motion Capture Technology, the team conducted motion capture trials with a greyhound. The movements gave them a 3D captured motion of a dog, to study behaviour over seven actions such as running, jumping, and chasing. This provided a base reference for A.X.L.’s movement that could be analysed in 3D.
“The mocap was very useful reference, but ultimately it was our animation team who brought A.X.L. to life in our sequences. The audience had to feel warmly towards this creature, which could otherwise come across as a monster… it needed a lot of refinement in it’s acting ,” said Sutton.
In a key sequence, a fully CGI A.X.L. is covered in drones, which in turn were attached by wires to the ceiling. The team had to simulate the wire systems attached to him responded in a dynamic way without becoming a tangled mess.