Ice Age Giants: Filming animated creatures in the wild
During the last Ice Age the northern hemisphere was teeming with fabulous megamammals – terrifying sabre-toothed cats, huge woolly rhinos, bizarre glyptodonts – but they all disappeared as the planet moved into a new, warmer era.
I'm one of the producers on the new series Ice Age Giants, who along with the rest of the team, was tasked with bringing those long extinct animals back to life.
Step back in time to meet the Ice Age megamammals
The CGI brief was to create animals that looked as real as possible so that the animation could pass as natural history footage.
Having never worked on a creature animated show before, I was excited and curious about how it all worked.
We drafted a storyboard of what we wanted our animals to do, and set off to film the backplates - the 'real life' backgrounds that we drop our animated creatures into.
The shasta ground sloth has seven-inch long claws to defend itself
For the most part the backplates were shot where the animals once lived, so the sabre-toothed cat was shot in LA, the mammoths just outside San Francisco, the armadillo-like glyptodonts in Florida and the ground sloth in the Grand Canyon.
It's a complicated process, but the key things were to put the animal in context and try to film it as we would an animal in the wild.
All very well, but the animal in question wasn't actually there. This is when we realised that we, the production crew, would have to stand in.
As you can see in our video, we were given a ball by the animation team. One side was grey matte, the other silver mirror.
Mags filming the territory of the iconic sabre-tooth cat in Los Angeles
The ball was to be held in the approximate position of the head of the animal and we should carry it through the action sequence we were filming.
The silver ball would record the direction of the light so that when they came to build the animal, they could light it accordingly and it would fit in naturally to its surroundings.
So having recorded several vital details for the animation team – focal length, height of camera off ground, distance from animal etc, I found myself filming just below the iconic Griffiths Observatory in LA, as had James Dean before me.
Instead this time I was pretending to be the sabre-toothed cat, or smilodon - that's me in the clip.
Repeated takes of me holding a silver ball, slinking up to a ridge overlooking downtown LA, whilst a crane swung above me, were watched by many confused onlookers.
To add to my acting credits I can also claim to have been the startled shasta ground sloth in episode one.
By planning the sequence carefully and thinking about the animal’s behaviour, we were able to film movement that would let the animated animals interact with the environment – such as eating bushes, splashing water and kicking up dust and snow.
We returned the footage to the animation team at the post-production company The Mill (who have also worked on Doctor Who). They set to work on by far the most complicated process of all, building the animals.
See how the special effects and production teams create realistic Ice Age giants
From a concept drawing, they carefully constructed grey-scale drafts which we sent to our experts around the world for comment on shape, size, etc.
The animation team then rigged the creatures - meaning they prepare them for movement.
They build an internal skeleton, then overlay it with muscle and skin and then the figures were animated, creating creepily realistic movement.
The visual effects team's attention to detail was excellent – our sabre-toothed cats had ears that twitched when flies bothered them, and the paws of the cave lion splayed as it prepared to pounce.
They developed existing technology for Ice Age Giants, so that over three million hairs are visible per creature!
We were delighted with the results, as were our experts. The creature animation really took us back in time and brought these Ice Age giants to life!
Comments made by writers on the BBC TV blog are their own opinions and not necessarily those of the BBC.