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1570 Chapter 16: Material Editor, Materials, and Maps
for reflections, but if they are very weak, the
viewer can often not really tell.
• For moderately blurry surfaces, set an even
lower Reflection Glossiness value and maybe
increase the Reflection Glossy Samples value.
Again, for improved performance turn on Fast
(interpolate).
• Forextremelyblurrysurfacesorsurfaces
w ith very weak reflections, try turning on
Highlights+FG Only.
A ty pical wooden floor could use Reflection
Glossiness of 0.5, Reflection Glossy Samples of 16,
Reflectiv it y of 0.75, a nice woo d texture for Diffuse
Color, perhaps a slight bump map. If bumpiness
should appear only in the lacquer layer, turn on
Special Purpose Maps rollout > Do Not Apply
Bumps To The Diffuse Shading.
Linoleum flooring could use the same settings
butwithadifferenttextureandbumpmap,and
probably with slightly lower Reflectivity and
Reflect ion Glossiness values.
Ceramics
Ceramic m aterials are glazed; that is, they’re
covered by a thin layer of transparent material.
They follow rules similar to the general materials
mentioned above, but choose By IOR (fresnel
reflections) and set IOR to about 1.4 and
Reflectivity to 1.0.
Set the Diffuse Color to a suitable texture or color,
such as white for white bathroom tiles.
Stone Materials
A stone object usually has a fairly matte finish, or
has reflections that are so blurry they are nearly
diffuse. You can simulate the “powdery” character
of stone with the Diffuse Roughness parameter;
try 0.5 as a starting point. Porous stone such as
brick would have a higher value.
Stone would have a very low Reflection Glossiness
(lower than 0.25) and one can most likely u se
Highlights+FG Only to good effect for very good
performance. Use a nice stone texture for Diffuse
Color, some kind of bump map, and perhaps a
map that varies the Reflection Glossiness va lue.
The Reflectivit y would be around 0.5-0.6 with
By IOR (fresnel reflections) off and 0 degree
reflect iv ity at 0.2 and 90 degree reflectivity at 1.0
Glass
Glass is a dielect ric, so By IOR (f resnel reflections)
should definitely be on. The IOR of standard glass
is 1.5. Set Diffuse Level to 0.0, Reflectivity to 1.0
and Tr ansparency to 1.0. This is enough to create
basic, completely clear refractive glass.
Ifthisglassisforawindowpane,turnThin-walled
on. If this is a s olid glass block, turn Thin-walled
off and consider if caustics are necessar y or not,
and set Refractive C austics according ly.
If t he g lass is frosted, set Refraction Glossiness
toasuitablevalue.TunetheRefractionSamples
for good quality or turn on Fast (interpolate) for
performance.
Colored glass
Forclearglass,usethetipsinthepreceding
section. Colored glass, however, is a different stor y.
Many shaders set the transparency at the surface of
the glass. And indeed this is what happens if one
simply sets a Refractive Color to some value, such
as blue. For glass with Thin-walled turned on this
works perfectly. But for solid glass objects this is
not an accurate representation of reality.
The scene in following illustration contains two
glass blocks of different sizes, a sphere with a
spherical hole inside it, and a glass horse.
Note: The spherical hole was created by inserting a
second sphere with its normals flipped inside the