9

RGB (SGI Image) Files 633
Coverage—
Saves the coverage of the surface
fragment from which other G-buffer values
(Z Depth, Normal, and so on) are obtained.
Z-Coverage values range from 0 to 255. To see Z
Coverage,rendertoanRLAfileafterfirstchecking
Z Coverage in the Setup subdia log, then choose
Z-Coverage in the rendered frame window’s
Viewing Channel drop-down list.
TheZ-Coveragefeatureisprovidedprimarilyfor
developers, and should aid in the antialiasing of
Z-buffers.
Node R ender ID—Saveseachobjectasasolidcolor
according to its G-Buffer Object channel (found
under Object Properties).
Co lor—Saves the color returned by the material
shader for the fr agment. This channel displays any
transparentfragmentasasolidcolor.
Tra nspare ncy—Saves transparency returned by the
material shader for the fragment. Any fragment
with an y degree of transparency will be rendered
as a solid g ray object.
Velocity—Saves the velocity vector of the fragment
relative to the screen in screen coordinates.
Sub-Pixel weight—Saves the sub-pixel weight of a
fragment. The channel contains the fractions of
the total pixel color contributed by the fragment.
The sum of all the fragments gives the final pixel
color. The weight for a given fragment takes into
account the coverage of the fragmen t and the
transparency of any fragments that are in front of
agivenfragment.
Sub-Pixel M ask—Saves the sub-pixel alpha mask.
Thischannelprovidesamaskof16bits(4x4)per
pixel, used in antialiased alpha compositing. This
mask is especially useful with the Combustion
compositing product.
Descriptive Information group
This information is saved w ith the file.
Descr iption—You can enter descriptive text here.
Author—You can enter your name here.
RGB (SGI Image) Files
The SGI™ Image File format is a bitmap file t ype
created by Silicon Graphics®. SGI Image File
support in 3ds Max lets you load and save files
in both 8- and 16-bit color depth, with alpha
channels, and RLE Compression.
Interfa ce
Clicking Render or Setup in the Render Output
File dialog (page 3–9) displaystheRGBImageFile
Format dialog.
Channel Bit Depth gro up
8Bit—SavestheRGBfileas8-bitcolor.
16 Bi t—SavestheRGBfileas16-bitcolor.
Use A lpha toggle
Use A l pha —Saves Alpha channels with the RGB
file.
TGA (Ta r ga ) Fi les
The Targa (TGA) format was developed by
Truevision for their video b o ards. The format
supp orts 32-bit t rue color ; that is, 24-bit color plus
an alpha channel, and is ty pical ly used as a true
color format.