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1558 Chapter 16: Material Editor, Materials, and Maps
Max Distance—
Allows limiting refraction to a
certain distance.
Color at Max Distance—When on, the material
simulates physically correct absor ption. At the
distance specified by Max Distance, t he refracted
imagehasthecolorgivenbyColorAtMax
Distance, but the rays are not limited in reach. At
twice the distance, the influence of Color At Max
Distance is double, at half the distance ha lf, etc.
When off, transparency rays simply fade to
black. This is like s moked g lass and other hi g h ly
absorbent materials. Transparency just stops
at the specified distance. This has the same
performance advantage as using the Max Distance
forreflections:Tracingshorterraysismuchfaster.
Avai lable only when Max Distance is on.
Left: No limit (Max Distance=off); Center: Fade to black; Right:
Fade to blue
Max Trace Depth—When this trace depth is
reached, the material refracts black.
Cutoff Threshold—The level at which refraction is
rejected; that is, not traced. It’s a relative value: For
example, the default sett ing of 0.01 means that rays
that contribute less than 1 percent to the final pixel
are ig nored. A setting of 0.25 means that mental
raydiscardsraysthatcontributelessthanaquarter
of the value of the final pixel.
Advanced Reflectivity group
V isible area lights cause no Highlights—When
on, mental ray area lights (Omni (page 2–1298)
and Spotlight (page 2–1299))withtheShow
Icon In Renderer property on create no specular
highlights. Default=on.
TheShowIconInRenderercheckboxisfoundon
the light’s Area Light Parameters rollout. When
on, the light is visible and reflects in any glossy,
reflective objects. If both the reflection of the
visible area light and the highlight is rendered,
the light is added twice, causing an un realistic
brightening effect. When on, this sw itch causes
visiblearealightstolosetheirhighlightsand
instead only appear as reflections. Note that this
does not apply to the Highlights+FG Only mode,
which doesn’t actually reflect anything.
Skip r eflecti ons on ins ide (except tota l inter nal
reflection)—
Most reflections inside transparent
objects are very faint, except in the special case that
occurs at certain angles k now n as total internal
reflection (TIR). When on, this option saves
rendering time by ignoring the weak reflections
completely but retaining the TIRs. Default=on.
Advanced Transparenc y Options group
The options give you control over some of the
deepest details of the Arch & Design material.
Glass/Translucency treat objects as...—
• Solid—The object behaves as if it is made of a
solid, transparent substance.
•
Thin-walled—The object behaves as if made of
wafer-thin sheets of a transparent material.
For more information, see Solid vs. Thin-Walled
(page 2–1567).
Left:Solid;Right:Thin-walled