I completed a months work on Tim Burton’s Sweeney Todd in which time I worked on lookdev and lighting of digital cockroaches that infest Mrs Lovett’s pie shop.

The cockroaches needed to be done completely digitally as there are no animal trainers that can work insects reliably! They are seen scurrying around the kitchen worktop, diving into pies and generally making Mrs Lovett’s life harder.

I used a combination of HDR images gathered on set and reflection cards (on which I painted custom highlight shapes) to get the reflection in the exoskeleton and wings looking realistic. I also used sub-surface scattering to accurately simulate the translucent nature of the thinner areas of the roaches. To give a softer ambient look, and to replicate the varying bounce light from the work top they walk on, I used a technique whereby pointclouds are generated from a rough model and a projection of the photographed plate. This allows the area light to have colour information that fits the scene; when the roach is walking near a white object, like the flour used for baking, it recieves more bounce light. This is an approxiation of global illumination - but much faster, and is suitable for production rendering.