Belle. Jasmine. Ariel. What did they all have in common? Aside
from a freakishly small waist, each of the Disney heroines also had giant, perfect eyes
with expressions ranging from wide-eyed excitement, to narrow-eyed
suspicion. Enough's enough, said computer graphics experts at Disney Research Zurich and ETH Zurich.
If they can figure out a way to enable people to "feel" 3D objects, and 3D-print interactive teddies, surely they can give Disney
characters some important expressive abilities. So that is what
they set out to do, with a complex setup of cameras and some
willing human subjects.
In a paper describing the experiments entitled High-Quality
Capture of Eyes, the team points that despite the human eye
being "one of the central features of individual appearance", and
obviously one that is most expressive, "its shape has so far been
mostly approximated in our community with gross
simplifications".
In their new approach -- as described in the paper and presented
at SIGGRAPH Asia 2014 last week -- the team used multiple cameras
and different lighting to capture all the intricacies of the human
eyeball -- the texture variations, colourings, veins and
refractions that make it such a dynamic feature, changing every
millisecond according to the environment.
They write: "We propose a novel capture system that is capable
of accurately reconstructing all the visible parts of the eye: the
white sclera, the transparent cornea and the non-rigidly deforming
coloured iris."
Each part behaves differently and reflects light differently, so
the team decided they must be dealt with individually. The process
also means a break away from the perfection of heroines of old.
Eyes are asymmetrical and contain imperfections, the team points
out. And most importantly, every person's eyes are totally
different from another's.
To get enough data, the team used six cameras, including 100mm
macro lenses focussed on the iris. Flash lighting using different
levels of brightness and coloured LEDs were chosen to get different
effects reflecting off the cornea, and actors were asked to lie on
the floor wearing a headset during the process. Eleven poses were
used all together, and the whole thing took about 20 minutes to
complete. Images were stitched together to begin to form the basis
of the eye movement -- for instance, the team found ten images was
enough to get the information to replicate iris deformation, while
140 were needed in total. A facial scanning system designed to
reconstruct skin was used to generate the eye model.
The main achievement has been to model how the iris responds to
light, which is probably the most obvious change to the eye we all
notice day to day. The team is now working on other changes to the
sclera and cornea.
The technology could help bring characters to life in games and
on film, potentially using the voice actors as models to bring more
of their character into the medium.
The Zurich group is duly proud of the progress, saying: "We
believe that the findings of this paper will alter our community's
current assumptions regarding human eyes, and our work has the
potential to significantly impact the way that eyes will be
modelled in the future."
"Generically modelled eyes may be sufficient for background
characters, but it now takes significant effort to manually create
realistic eyes for heroes and other leading characters," commented
coauthor on the paper, computer graphics PhD student Pascal Bérard.
"Our reconstruction technique can greatly reduce the time spent and
help increase the realism of the eye."
Source Article from http://www.wired.co.uk/news/archive/2014-12/08/disney-research-realistic-eyeballs http://cdni.wired.co.uk/620x413/s_v/shutterstock_186641597.jpg
Disney Research delivers hyper-realistic animated eyeballs
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