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Arch & Design Mater ial (mental ray) – Tips & Tricks 1569
Perf or mance Featu res
Finally, the Ar ch & Design material contains a large
set of built-in functions for optimal performance,
including but not limited to:
• Advanced importance sampling with ray
rejection thresholds
• Adaptive glossy sample count
• Interpolated glossy reflection/refraction with
detail enhancements
• Ultra-fast emulated glossy reflections
(Highlights+FG Only mo de)
• The option to ignore internal reflections for
glass objects
• The choice between traditional transparent
shadows, suitable for objects such as a window
pane, and refractive caustics, suitable for solid
glass objects, on a per-material basis.
Arch & Design Material (mental
ray) – Tips & Trick s
This topic contains information to help you more
effectively use the Arch & Design material (page
2–1549) for mental ray.
See also
Arch & Design Material (mental ray) – Overview
(page 2–1562)
Arch & Design Material (mental ray) (page 2–1549)
Fi n al G a the r Perf o rm ance
The final gather algorithm in mental ray 3.5 is
vastly improved from earlier versions, especially
in its adaptiveness. This means you can often use
much lower ray counts and much lower densities
than in previous versions of mental ray.
In many cases, you can render st i ll images with
suchextremesettingsas50raysandadensity
of 0.1. If this causes “oversmoothing” art ifacts,
you can use the built-in ambient occlusion (page
2–1555) to solve those problems.
When using final gather together w ith GI
(photons), make sure the photon solution is
fairly smooth by first rendering with Final Gather
disabledfirst. Ifthephotonsolutionisnoisy,
increase the photon search radius until it “calms
down,” and then enable Final Gather.
Qui ck G ui de t o S o me Common M a t er i a ls
Following are some quick rules of thumb for
creating various materials. Each assumes the basic
default settings as a starting point.
General Rules of Thumb for Glossy Wood,
Flooring, etc.
These are the k ind of “hybrid” materials you mig ht
require for architectural renderings; lacquered
wood, linoleum, etc.
For these materials, set BRDF to Custom
Reflectivit y Function; that is, you’ll define a
custom BRDF curve. Start out with 0 degree
reflectivity of 0.2, 90 degree reflectiv ity of 1.0, and
apply a suitable texture map to the Diffuse Color.
Set Reflectiv ity b etween 0.6 and 1.0.
How glossy is the material? Are reflections clear or
blurry? Are they strong or weak?
• For clear, fairly strong reflections, keep
Reflection Glossiness at 1.0.
• For slightly blurry but strong reflections,
set a lower Reflection Glossiness value. If
performance becomes an issue try turning on
Fast (interpolate).
• For slightly blurry but also very weak
reflections, you can “cheat” by applying a
lower Reflect ion Glossiness value for broader
highlights while setting Reflection Glossy
Samplesto0.Thisshootsonlyonemirrorray