Tuesday 12 January 2016

Walking (and making) the dinosaur



I was fortunate enough to work on a fascinating project last year led by Dr. Bill Sellers from the University of Manchester and which was published as a Peer-J preprint just before Christmas. The full preprint is available here: https://peerj.com/preprints/1584/

Dr. Sellers has been working on the biomechanics of dinosaurs and other tetrapods for several years and has developed an application called GaitSym that calculates walking or running gaits, testing walk cycles until the program finds the most efficient which can help form a hypothesis to be formed on how an animal might have moved around. GaitSym requires 3D skeletal data in the form of scans or models that are then rigged with muscles that allow the simulation to calculate the forward dynamics.

Dr Sellers then built a new version of GaitSym that allows people to control dinosaurs themselves. By replacing the algorithms that calculate forward dynamics with an external control system, in this case a Kinect for Xbox wired up to a Windows PC, a person standing a few feet away can control the rigged dinosaur on the screen, enabling it to walk, run or dance.

Triceratops skeleton rigged with virtual muscles in GaitSymKinect.
Image courtesy of Dr. William Sellers.

The software created by Dr. Sellers that allows people to control these dinosaur skeletons is called GaitSymKinect. The dinosaur skeletons are rigged as we think they would be in life and GaitSymKinect translates the movements of the user into movement for the dinosaurs, allowing a person to make Tyrannosaurus rex do the Charleston, or a Triceratops gallop. The system was tested last year at the Cheltenham Science Festival and is now freely available, along with the dinosaur skeletons to go with it, follow this link here: http://www.animalsimulation.org/files/84eab05587dbe0bdcd72eb098a692afe-7.html

My part was to create the dinosaur skeletons to be used in GaitSymKinect whilst also making them suitable for being made freely available for 3D printing and just about anything else a 3D mesh can be used for. The skeletons were created to be as accurate as possible whilst not representing an actual specimen; scans, photogrammetry and the literature were all sources referred to when creating the skeletons. They are not detailed down to the smallest foramen in order to keep the polygon count as low as possible but they are accurate and would be useful for adapting to specific specimens if required and were created in Maxon Cinema 4D R16 and zBrush 4R7.

Six complete skeletons were created: Tyrannosaurus, Gorgosaurus, Triceratops, Edmontosaurus, Brachiosaurus and Edmontia. The final skeletal models are ideal for biomechanical work, adding to artworks and of course 3D printing. All this and they are free, released under CC-BY The dinosaurs skeletons modelled are shown below. If you do use them for anything, it’d be great if you could show us what you’ve done with them.


The six dinosaur skeletons built as 3D meshes and available for free download.
Clicking should embiggen.


References:


Sellers WI, Pond SB. (2015) Kinect controlled dinosaur simulations for education and public outreach. PeerJ PrePrints 3:e1979 https://doi.org/10.7287/peerj.preprints.1584v1