Lexhag VFX used Houdini to create CG simulations to completely cover lead actor, Tim Key, in a swarm of bees for Baby Cow’s six-part comedy series, The Witchfinder. The series, which aired on BBC Two in February, follows a failing Witchfinder Tim Key as he takes a suspected Witch played by Daisy Donnelly across 1640s East Anglia to a trial that could change his fortune forever.

The season finale was heavily reliant on covering Tim Key in bees from head to toe. For obvious reasons, this wasn’t achievable practically so we created this as a visual effect, using Houdini to simulate tens of thousands of bees wrapped around a human figure.

The first part of the process was digitally tracking Tim Key’s performance in a process called Matchmove. For this, we generated an exact likeness of Tim in the form of a digital double based on set measurements and photographs. This double was manipulated much like a puppet to exactly match Tim’s movement during his performance. We used this movement as a ‘base’ in Houdini and wrapped it in bees with their motion simulated.


Unlike traditional animation, each bee on the suit was not hand-animated. Instead, Houdini gave each bee a number of variables such as leg movement, body wobble and wing flutter which was randomised and simulated over the course of each shot. This gave the effect that each bee was an independent ‘particle’ (much like the real thing) and produced a random fluid effect of bees crawling over each other.

We used a similar technique to produce bees flying around in a swarm. With both of these CG passes (bee suit and swarm) supplied to comp, we were able to add final effects such as motion blur and grading to bed everything into the scene and produce the final results seen in the show.