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632 Chapter 20: Managing Scenes and Projects
post-production or effects work. Many channels
available in RPF files are exclusive to t his format.
Tip: When you create a scene you plan to
render as an RPF file for use with the Autodesk
Combustion™product,turnonRenderOccluded
Objects (on the Object Pr operties dialog (page
1–117) ) for objects in the scene. This is important
if you want to use the Combustion G-Buffer
Extract feature. When Render O ccluded Objects is
enabled and you extract an object in Combustion,
the objects behind it are drawn correctly. If Render
Occluded Objects is disabled (the default), objects
behind the extracted object appear with black
holes where they were occluded.
Inter face
When RPF is the chosen output format, clicking
Render or Setup on the Render Output File dialog
(page 3–9) displaystheRPFImageFileFormat
dialog.
Standard Channels group
The standard channels are RGB color and the
alpha (transparency) channel.
B its per Channel—Choose 8, 16, or 32 Floating
Point as the number of bits per channel. Default=8.
Stor e Al pha Channel—Choose w hether to save the
alpha channel. Default=on.
Premultiply A lpha—When on, premultiplies the
alpha channel. Default=on.
Premultiplying saves computation time if you later
use this image in compositing. See Premultiplied
Alpha (page 3–997) for more information.
Optional Channels group
For output RPF files, there are additional channels
that you can generate (and view in the rendered
frame w indow):
ZDepth—Saves Z-Buffer information in repeating
gradients from white to black. The gradients
indicate relative depth of the object in the scene.
Material ID—Displays the Effects channel u sed
by materials a ssigned to objects in the scene.
The Effects channel is a material property set in
the Material Editor and used during Video Post
compositing. Each Effects Channel ID is displayed
using a different random color.
Object ID—Displays the G-Buffer (page 3–946)
Object Channel ID assig ned to objects u sing the
Object Prop erties dialog. The G-Buffer ID is used
during Video Post compositing. Each G-Buffer ID
is displayed using a different random color.
UV Coordina tes—Sav es the range of UV mapping
coordinates as a color gradient. This channel
shows where mapping seams might o ccur.
Note: UV Coordinates will not be displayed on
objects that have the UVW Map Modifier applied
unless a map has been applied that uses the
coordinates.
Nor mal—Saves the orientation of normal vectors
as a grayscale gradient. Light gray surfaces have
normals pointing toward the view. Dark gray
surfaces have normals pointing away from the
view.
Non-Clamped Color—Saves areas in the image
where colors exceeded the valid color range
and were corrected. The areas appear as
bright saturated colors usually around specular
highlights.