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Photons/Samples Sets how many photons are used to compute the intensity
of the global illumination. Increasing this value makes global illumination
less noisy but also more blurry. Decreasing this value makes global illumination
more noisy but less blurry. The larger the Samples value, the greater the
rendering time.
Use Radius Determines the size of photons. When on, the spinner value sets
the size of photons. When off, each photon is calculated to be 1/10 of the
radius of the full scene.
Radius Specifies the area within which photons will be used when illuminance
is computed.
Max Depth Limits the combination of reflection and refraction. Reflection
and refraction of a photon stop when the total number of both equals the
Max Depth setting. For example, if Max Depth equals 3 and the trace depths
each equal 2, a photon can be reflected twice and refracted once, or vice versa,
but it can’t be reflected and refracted four times.
Max Reflections Sets the number of times a photon can be reflected. At 0,
no reflection occurs. At 1, the photon can be reflected once only. At 2, the
photon can be reflected twice, and so on.
Max Refractions Sets the number of times a photon can be refracted. At 0,
no refraction occurs. At 1, the photon can be refracted once only. At 2, the
photon can be refracted twice, and so on.
Final Gather
Calculates global illumination.
Mode Controls the final gathering dynamic settings.
■ On. Turns on the global illumination in final gather.
■ Off. Turns off the calculation of global illumination in final gather.
■ Auto. Indicates that the final gather should be dynamically enabled or
disable at render time based on the skylight status.
Rays Sets how many rays are used to compute indirect illumination in a final
gather. Increasing this value makes global illumination less noisy, but also
increases rendering time.
Radius Mode Determines the radius mode for final gather processing. Settings
are On, Off, or View.
■ On. Specifies that the setting means the Max Radius setting is used for final
gather processing. The radius is specified in world units, and defaults to
10 percent of the maximum circumference of the model.
1676 | Chapter 18 R Commands