Weighing a staggering 70 tonnes and measuring 37 metres long, the Titanosaur is the largest creature ever to have walked the Earth. Its heart alone had a six-foot circumference and weighed over 200 kilograms.

More than 200 bones belonging to the creature were recently discovered in Patagonia, after a farmer stumbled across a 2.4 metre-long femur. The subsequent archaeological dig, and research to determine the creature’s weight and size, was documented in an hour-long show on BBC One last night, presented by David Attenborough.

The programme showed how 3D scanning was used to create digital models of the 101 million-year-old bones and create a life-sized fibre glass model, which was assembled in a warehouse in Argentina.

Design studio Hello Charlie created a ghostly CG Titanosaur for the programme, which appeared in several scenes with Attenborough and was used to illustrate the dinosaur’s anatomy and how its organs functioned. The studio also created a model showing how the creature might have looked in the flesh and a moving baby Titanosaur which was pictured inside an egg.

The skeletal model was based on 3D scans of bones discovered at the dig site and others belonging to closely related animals. With 65 to 75% of the Titanosaur’s skeleton recovered in Patagonia, experts were able to create incredibly detailed scans accurate up to 0.01mm.

“We received the full CGI data of the actual scanned bones,” explains Hello Charlie’s Andy Power, who worked on the CG build, lighting and animation. “These scans were incredibly detailed – so detailed in fact that the quantity of data was beyond what conventional CGI systems can handle. We had to intelligently reduce this information in the model without compromising the integrity,” he says.

CG models of soft tissue elements such as skin, muscles and internal organs were based on consultations with experts in evolutionary biology and biomechanics, who provided input throughout the process, says Power.

Hello Charlie also consulted with expert illustrators and studied rare skin samples to determine what the creature might have looked like from the outside. “Although bones reveal an enormous amount about the creature, there is no way of knowing what living dinosaurs exactly looked like,” explains Power. “Our CGI build was based on the illustrations of specialist paleo-artists, information from the comparative anatomy scientists and source material in the form of embryo titanosaur skin found at another Argentinian dig site, [which was] then refined based on further input from the scientific experts,” he adds. “Every rigorous measure was taken to ensure that the CGI representations of the creature were accurate based on current, collective, scientific understanding.”

In its skeletal form, the creature has a ghostly appearance – but it’s also incredibly detailed. Gavin Lamb, who worked on the VFX concept, design and direction, describes it as a “stylised apparition” and says the aim was to avoid anything gory or sensationalist when showing how the dinosaur’s internal organs would have worked.

“We wanted [the scenes] to have a scientific integrity combined with a feeling of magical wonder,” he says. “Also, as the sequences with David Attenborough were to be filmed in a vast empty warehouse with very little natural light, we liked the idea of the graphics illuminating both David and the scene,” he adds.

After devising a storyboard with director Charlotte Scott, Hello Charlie travelled to Patagonia with Attenborough and the production team to supervise the filming of VFX scenes. “Working from a script we were aware of the structure the sequences would take and what the final shots needed to show. We also built a basic CGI scale model of the scene to test our shots in context,” says Lamb.

“At the location, we carefully mapped the dimensions, placed tracking markers around the space and photographed every surface for reference. We also provided markers for each of the key anatomical features, such as the head, heart and lungs, for David Attenborough to use for eye-line reference – these were helium filled balloons, tied to measured string and weighted down in position.”

One of the most challenging elements of the project was building a baby Titanosaur, which was shown inside an egg (below). To create it, the team scaled down an adult model and adjusted proportions in line with the dinosaur’s likely stage of development. The model was then re-skinned and rigged and other details such as eyes, eyelids, claws and an egg tooth applied. 

Remnants of fossil embryo skulls and bones helped the team establish the infant dinosaur’s proportions, while the skin texture was based on photographs of a rare portion of a fossilised baby Titanosaur, found by a palaeontologist in Argentina, explains Power.

“The movement of the baby dinosaur needed to be convincingly erratic and organic, this was achieved by interpreting specially recorded motion capture data,” he adds. “To accurately represent the movement of the nictitating membrane that slides across the eye, we were advised to base the movement on that of reptiles. We encased the CGI model within an outer sac, and used cloth dynamics to both stretch the sac over the embryo and follow its movements. The finished CGI renders included a combination of depth particles, refraction techniques and carefully placed lighting, with additional effects added in post. The CGI was then carefully composited into shots with David Attenborough.”

UK viewers can watch the show on iPlayer here.

Credits (VFX)

Concept, Design and Direction: Gavin Lamb
CGI Build, Lighting and Animation: Andy Power
Lead Compositor and VFX: Tom Lee
Producer: Alex Briggs
Creative Director: Paul Tigwell
Client: BBC Earth and PBS co-production ‘Attenborough and the Giant Dinosaur’