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80 Chapter 17: Rendering
•Outputditheringoptionsaren’tsupported
(in Main menu > Customize > Preferences >
Preference Settings dialog > Rendering panel >
Output Dithering group).
• Thementalrayrendererdoesnotfullysupport
G-buffer options in p ost processing and image
file output. T he mental ray renderer generates
all required G -buffer channels, but do es not
include transpar ency information. If two
transparent objects overlap each other, the
mental ray render generates information only
for the frontmost object.
• When you use a bitmap as an environment (that
is, as a background), the mental r ay renderer
will sample it and filter it. This can result in
unwanted blurring. To prevent background
blurring, render the scene against a solid-color
background, and then composite the rendered
scene with the background image.
• Sometimes when you render objects that
have zero thickness, or an Extrude modifier
w ith zero thickness, the mental ray renderer
generates rendering artifacts that appear as
streaks. In some cases, you can fix this by
turningonForce2-SidedintheRenderScene
dialog’s Common Parameters rollout. If the
streaks persist, give the object or the Extrude
modifier a nonzero thickness.
See also
Sampling Quality Rollout (mental ray Renderer)
(page 3–98)
Camera Effects Rollout (mental ray Renderer ) (page
3–101)
Caustics and Global Illumination Rollout (mental
ray Renderer) (page 3–106)
Final Gather Rollout (mental ray Renderer) (page
3–111)
Shadows and Displacement Rollout (mental ray
Renderer) (page 3–114)
Rendering Algorithms Rollout (mental ray
Renderer) ( page 3–116)
Translator Options Rollout (mental ray Renderer)
(page 3–119)
Distributed Bucket Rendering Rollout (mental ray
Renderer) ( page 3–124)
Procedures
To us e the menta l ray r enderer :
1.
Choose Rendering menu > Render . The Render
Scene dialog displays.
2. On the Common panel, open the Assign
Renderer rollout, then click the “...” button for
the Production renderer.
AChooseRendererdialogisdisplayed.
3. OntheChooseRendererdialog,clicktoselect
mental ray Renderer , and then click OK.
Now when you render, the Render Scene dialog
appears with the mental ray controls. You can
choose to render the scene w ith the built-in mental
ray renderer, or simply to tr anslate the scene and
save it in a .mi f ile (page 3–972) that you c an render
later , perhaps on a different system. Controls for
choosing whether to render, save to a .mi file, or
both, are on the Translator O ptions (page 3–119)
rollout.
To make the menta l r ay R ender er the def au lt
render er for new scenes:
• After you make the mental ray renderer the
active production renderer, click Save As
Defaults on the Assign Renderer rollout.
Getting Good R esults with mental
ray Rendering
Although the mental ray renderer is relatively
easytouseonceyou’vesetitupcorrectly,there
are several "gotchas" t hat you might encounter