Friday 2 January 2015

LAIKA: 3D Printing & Rapid Prototyping

        Through the technique of rapid prototyping, LAIKA manage to achieve the best of both worlds in their animation: the quirky charm and individuality of stop motion, with the greater range of facial expression and emotion provided by computer animation.

        While rapid prototyping employs the same principles of replacement animation that have been used in stop motion for decades, the increased number of replacement mouths and brows means that the characters Norman (Paranorman) and Eggs (The Boxtrolls) have up to 1.4 million potential expressions. This allows for greater emotional depth and subtle differentiation between the replacements, as tiny twitches of a lip or cheek can be picked up in the 3D prints which would be difficult for hand sculpted faces to achieve. The illusion of an underlying musculature helps to draw a naturalistic performance from the puppets.


        Other techniques have been tried and tested to achieve the same level of naturalism. Mackinnon and Saunders created 40 intricate mechanised heads for Corpse Bride, which with the turn of an Allen key would allow a character to smile, frown or lip synch with a high degree of  depth and subtlety. Both methods are innovative, both allow the animators greater freedom than hand sculpted replacements, and both have their advantages. The mechanised heads wouldn't impose on the animators the restrictions caused by facial expressions needing to be predetermined and printed prior to animation; they could be animated on set. The rapid prototypes, on the other hand, arguably have more range, as they aren't constricted by the underlying mechanical structure; one-of-a-kind facial expressions could be designed and printed specifically for individual shots, and used just once throughout production (for example vibrations reverberating through a character's 'flesh').


       To create this vast library of replacements, hand sculpted models of the puppets are made and digitally scanned, so that they can be brought into programs such as Maya and ZBrush. A stop motion animator and a CG animator will then work alongside one another to compile a library of expressions that can then be printed and delivered to the set. In the case of The Boxtrolls, 52,000 different facial parts were printed.


        One challenge of this technique is that the facial expressions needed to be chosen and decided upon weeks before the puppets are animated on set, meaning that the animators must separate facial and body animation. The animators initially found this counter intuitive, as the facial animation could not easily be altered to match any spontaneous nuances in the body animation. 

        Other technical problems inherent in this process include variations in the printed faces based on changes in humidity, deterioration in the printer heads due to the sheer volume of material being printed, and inconsistencies in the colours of the prints (the facial components were printed in colour rather than being painted later on). 


"There was no going back to hand sculpting faces. This afforded us to tell unbelievable stories to tell greater emotional range and more subtle character animation than we ever had in stop motion alone."
Brian McLean, LAIKA's director of rapid prototyping

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