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Thursday 22 December 2016

XROMM and Biomechanics Studies Benefit Animators

Some of the latest research occurring in biomechanics could be of great benefit to animation - especially VFX where recreations of creatures is often focused around being as realistic as possible.

I had the great honour of visiting the Royal Veterinary College last week and a piece of imaging technology that caught my eye was the XXROMM machine - a camera that films x-ray images. It has some limitations, only shooting a confined area means it's only able to capture small animals in full. However the images of these animals are very illuminating.

Here is a partridge scrambling up an incline under X-ray (XROMM)

As I've mentioned before, birds' wing bones are often hard to locate (due to the feathers) so to get a clear look at them is very insightful. It's also interesting to see and try to understand how their legs work too - the first joint (femur) is often hidden and, although the overall leg construction is similar to mammal quadruped hind limbs, it does not adhere to the same constrained linkage - which often keeps the femur and foot more or less parallel to each other.

I hope to write more about how bird legs work as well as how and why they evolved soon. But I digress. I was particularly intrigued by the implication of the advanced use of these machines -  by using twos XROMMs at different vantage points it is possible to 3D track animal bones as they move.

The study mentioned in the video above looked into the mobility of two different suborders of turtles  - those with their hips fused to their shells (Pleurodira) and turtles' who's hips are free to move (Cryptodira).


As you can see, the study quite conclusively shows that the turtles who's hips are free to move, use this ability to increase the range of movement from their hind limbs and therefore have a much better walking performance. Which is interesting in itself, but for me, the ability to watch how bones work in an animal while they move is truly fascinating. The article can be found here.

As 3D animators working with an animation rig we are generally trying to animate from the bones outward - the muscles, skin and fur usually being added by other departments. So the idea that we may be able to finally see what these bones are up to in real creatures under all that soft tissue could mean a much greater understanding of animal locomotion and an advancement in terms of realism in their movements.

A library of XXROMM movies can be found here.