Pixar has become one of the world’s most famous computer animation companies, with characters and objects constantly appearing more lifelike.
In its new Disney-Pixar flick Brave they managed to create extremely realistic hair, as their technology gets to grips with textures and fibres.
However, one area which has proved more difficult is knitwear.
Scientists at Cornell University have completed the incredibly complex feat of recreating knitting.
Traditionally, computer graphic artists simulate cloth by creating a thin sheet and then adding texture on top, but this doesn’t work for knitted garments.
To make the images more realistic computers have to be able to mimic the intertwining of the yarn, meaning they need to effectively learn how to knit.
Professor Steve Marschner, who led the research, said: “We are actually changing the shape of the yarn loops that make up the stitches, simulating how they wrap around other loops.”
But this is trickier than it sounds, as the images of the loops can’t slide out of place or they would unravel, much like what happens when stitches are dropped in real knitting.
Researchers found that the best way to create a knitted effect is to construct a 3D model of a single stitch, then combine multiple copies to form a mosaic-like mesh.
Each stitch will then be stretched and bent to fit the 3D surface.
This is no mean feat for computer graphic artists, who had to trawl through patterns from knitting books in order to painstakingly create accurate dresses, jumpers, scarves and even a tea cosy!
The research, which was supported by Pixar, the National Science Foundation, the John Simon Guggenheim Memorial Foundation and the Alfred P Sloan Foundation also made the technology able to simulate the effects of different needles, yarn or tension used by the knitter.
These parameters make it look far more realistic – especially to experienced knitters!
Article from Rowan.