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Sampling (mental ray Ren derer) 1005
effect is somewhat like the falloff of a soft-edged
spotlight.
ThedefaultSampleRangevalueis4.TheSample
Range value can be any floating-point number
from 0 to 20. Values of 2 to 5 are recommended.
Values below 3 can produce coarse-edged shadows.
You c an reduce this effect by increasing the map
size.
Va lues greater than 5 can produce streaking and
moiré patterns. You can reduce this effect by
increasing the m ap size or the Bias v alue.
Rendering time increases exponentially as the
Sample Range value increases.
S ampl ing (menta l ra y R end erer )
Sampling is an antialiasing technique. It provides
a "best guess" color for each rendered pixel. The
mental ray renderer (page 3–78) first samples the
scene color at locations within the pixel or along
the pixel’s edge, then uses a filter to combine the
samples into a single pixel color.
(In 3 ds Max, this technique is called
"supersampling." Because the mental ray
renderer performs sampling on a scene basis,
in the Material Editor, you don’t need to turn
on supersampling for materials rendered using
mental ray.)
Scene rendered with low sampling is jagged and inaccurate.
Sampling range: 1/64 to 1/4
Same scene rendered with higher sampling shows smooth
edges.
Sampling range: 1 to 16
The mental ray renderer provides five filter
methods: Box, Gauss, Triangle, Mitchell, or
Lanczos. Box, the default, is a lso t he quickest.
Mitchell is often the most accurate. The Box filter
combines samples evenly, without weighting them.
Eachoftheotherfiltersusesaparticularcurveto
weight samples before combining them.
Curves used to weight samples (these are approximate)