9

RPF Files 631
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. For more
information, see Premultiplied Alpha (page 3–997).
Optional Channels group
For output RLA files, there are eight additional
channels that you can generate (and view in the
rendered fr ame window):
ZDepth—Displays Z-Buffer information in
repeating gradients from white to black. The
gradients indicate relative dept h of the object in
the scene.
Mater ial ID—Displays the Effects channel used
by materials assigned to objects in the scene.
The Effects channel is a material prop erty set in
the Material Editor and used during Video Post
compositing. Each Effects Channel ID is display ed
using a different random color.
Object ID—Displays the G-Buffer (page 3–946)
Object Channel ID assig ned to objects using the
Object Properties dialog. The G-Buffer ID is used
during Video Post compositi ng. Each G-Buffer ID
is displayed using a d ifferent random color.
UV Coordinates—Displays the range of UV
mapping coordinates as a color gradient. This
channel shows where mapping seams mig ht occur.
Note: UV Coordinates w ill not be displayed on
objects that have the UVW Map Modifier applied
unless a map has been applied that uses the
coordinates.
Nor mal—Displays the orientation of normal
vectors as a grayscale g r adient. Light gray surfaces
have normals pointing toward the view. Dark gray
surfaces have normals pointing away from the
view.
Non-Cla mped Color—Displays 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.
Coverage—This saves the coverage of the surface
fragment from which other G-buffer values
(Z Depth, Nor m a l, and so on) are obtained.
Z-Coverage values range from 0 to 255. To see Z
Coverage,rendertoanRLAfileafterfirstchecking
Z Coverage in the Setup subdialog, then choose
Z-Coverage in the rendered frame window’s
V iewing Channel drop-down list.
The Z-C overage feature is provided primari ly for
developers, and should aid in the antialiasing of
Z-buffers.
Descriptive Information group
This information is saved with the file.
Descr iption—You can enter descriptive text here.
Author—You can enter your name here.
RPF Files
RPF (Rich Pixel Format) is the format that
supp orts the ability to include arbitrary image
channels. While setting up a file for output, if you
select RPF Image File f rom the list, you’ l l go to
the RPF setup dialog. Once there, you can specify
what channels you want to wr ite out to the file.
RPFfilesreplaceRLAfilesastheformatof
choice for rendering animations requiring further