on the appearance of translucent - harvard...
TRANSCRIPT
On the Appearance of Translucent EdgesIoannis Gkioulekas (Harvard), Bruce Walter (Cornell), Edward Adelson (MIT), Kavita Bala (Cornell), Todd Zickler (Harvard)
Different materials can look the same
albedo
first moment
second moment
Different geometries look different
albedofirst momentsecond momentdensity
refractive indexview anglelight angle
refractive index
view angle
light angle
absorption
scattering
density
phase function
albedo
η1
η2
view angle
light angle
η2 > η1
We examine sidelit, geometric edges…
opaque material familiar stepedge shape
translucent material oddlooking shape
…of translucent materials…
…which look different from opaque ones…
What do ideal translucent edges look like?four qualitatively distinct regions
local extremaaway from
edge
reflection boundary
refractioninternal reflection
view rays
light ray
intensity
lowflux area
highflux area
flux
single midorder highorder
single midorder
intensity
flux
phase functions
1 23 45 67 8
scattering events
Realworld edges look (something) like this
silicone 1
silicone 2
soap
wax
wax
paraffin
glycerinesoap
wax real edges are not ideal
00.050.10.2
bevel
Applications• features for material recognition and inference• image priors for translucent materials• edge detection on translucent objects• shapefromshading for translucent objects
Dataset
45,000 rendered edge profiles for different materials and geometries
http://vision.seas.harvard.edu/translucentedges
…and are important for human perception
fine geometric details
other features