9

Bitmap 2D Map 1633
The reduced image "decals" on the sample
sphere. The d iffuse color is visible around the
image.
To use the al pha channel that is par t of the bitmap:
1.
On the Maps rollout, ass ign the map to the
Opacity component.
(You can assign a copy or instance of this map
to other components, such as Diffuse, as well.)
2. Click t he map button for the Opacity
component.
This lets you adjust the sett ings for the Opacity
map.
3. In the Bitmap Parameters rollout > Alpha
Source group, choose Image Alpha.
This option is not available if the bitmap does
not have an alpha channel.
4. In the Bitmap Parameters rollout > Mono
Channel Output group, choose Alpha.
This option is not available if the bitmap does
not have an alpha channel.
The bitmapped material w i ll now have the
transparency specified by the alpha channel.
This will appear in renderings. Transparency
does not appear in viewports or Act iveShade
renderings.
To create an al pha channel b ased on i ntensit y :
• In Bitmap Parameters rollout > Alpha Source
group , turn on RGB Intensity.
The software creates an alpha channel.
Full-intensit y areas of the image are opaque,
zero-intensity areas are transparent, and
intermediate colors become partially
transparent.
To use a completely opaque bitmap:
• In Bitmap Parameters rollout > Alpha Source
group, turn on None (opaque).
The software ignores the bitmap’s alpha
channel, if present, and does not create a new
one.
Interfa ce
Bitmap Parameters rollout
Bitmap—Selects the bitmap using the standard
file browser. After selection, the full path name
appearsonthisbutton.
Reload—Reloads the bitmap file using the same
name and path. You don’t need to use the file
browser to reload the bitmap after you’ve updated
it in your paint program.
Clicking reload for any instance of the map updates
the m ap in all sample slots and in the scene.
Filtering group
Filter ing (page 3–939) options let you select the
method of pixel ave raging used in antialiasing
(page 3–907) the bitmap.
Pyramidal—Requires less memory and is adequate
for most purposes.
Summed Ar ea—Requires much more memory, but
yields generally superior results.
None—Turns off fi ltering.