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1314 Chapter 16: Material Editor, Materials, and Maps
The IOR con trols how severely the material
refracts transmitted light. Left at 1.0, the IOR
of air, the object behind the transparent object
does not distort. At 1.5 the object behind distorts
greatly, like a glass marble. At an IOR slightly less
than 1.0, the object reflects along its edges, like a
bubble seen from under water. Default=1.0.
Common IORs (assuming the camera is in air or a
vacuum) are:
Material IOR Value
Vacuum
1.0 (exactly)
Air
1.0003
Water
1.333
Glass 1.5 (clear glass) to 1.7
Diamond
2.417
In the physical world, the IOR results from the
relative speeds of light through the transparent
mater ial and the medium the eye or the camera is
in. Typically this is related to the object’s density;
the higher the IOR, the denser the object.
You can also use a map to control the index of
refraction. IOR maps always interpolate between
1.0 (the IOR of air) and the setting in the IOR
parameter. For example, if the IOR is set to 3.55
and you use a black-and-white Noise map to
control IOR, the IORs rendered on the object will
be set to va lues between 1.0 and 3.55; the object
will appear denser than air. If, on the other hand,
your IOR is set to 0.5, then the same map values
will render between 0.5 and 1.0, as if the camera
were under water and the object was less dense
than the water.
HerearesomemoreIORvaluesforvarious
mater ials:
Material IOR Value
Carbon Dioxide, Liquid
1.200
Ice
1.309
Material IOR Value
Acetone
1.360
Ethyl Alcohol
1.360
Sugar Solution 30%
1.380
Alcohol
1.329
Flourite
1.434
Quartz, Fused
1.460
Calspar2
1.486
Sugar Solution 80%
1.490
Glass, Zinc Crown
1.517
Glass, Crown
1.520
Sodium Chloride
1.530
Sodium Chloride (Salt) 1
1.544
Polystyrene
1.550
Quartz 2
1.553
Emerald
1.570
Glass, Light Flint
1.575
Lapis Lazuli
1.610
Topaz
1.610
Carbon Bisulfide
1.630
Quartz 1
1.644
Sodium Chloride (Salt) 2
1.644
Glass, Heavy Flint
1.650
Methylene Iodide
1.740
Ruby
1.770
Sapphire
1.770
Glass, Heaviest Flint
1.890
Crystal
2.000
Chromium Oxide
2.705
Copper Oxide
2.705
Amorphous S elenium
2.920
Iodine Crystal
3.340