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Bitmap 2D Map 1443
intermediate colors become partially
transparent.
To use a completely opaque bitmap:
• In Bitmap Parameters rollout > Alpha Source
group, turn on None (opaque).
Thesoftwareignoresthebitmap’salpha
channel, if present, and does not create a new
one.
Inter face
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
themapinallsampleslotsandinthescene.
Filtering group
Filtering (page 3–1033) options let you select the
method of pixel averaging used in
antialiasing
(page 3–1001)
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 filtering.
Mono Channel Output group
Some parameters, such as opacity or specular
level are a single value as opposed to a material’s
three-value color components. Controls in this
group determine the source of t he Output mono
channel in terms of the input bitmap.
RGB Intensity—Uses the intensity of the red, green,
and blue channels for mapping. The color of the
pixels is ignored and only the value or luminance
ofthepixelsisused.Thecolorsarecomputedas
gray values in the r ange between 0 (black) and 255
(white).
Alpha—Uses the intensity of the alpha channel
(page 3–1001)
for mapping.
RGB Channel Output group
The RGB Channel Output determines where the
output RGB part comes from. The con trols in this
group affect only maps for mater ial components
that display color: Ambient, Diffuse, Specular,
Filter Color, Reflection, and Refraction.
RGB—Displays the full color values of the pixels.
(Default)
Alpha as Gray —Displays tones of gray based on the
levels of the alpha channel.
Cropping/Placement group
Thecontrolsinthisgroupletyoucropthe
bitmap or reduce its size for custom placement.
Cropping a bitmap means to reduce it to a smaller
rectangular area than it originally had. Cropping
doesn’t change the sc ale of the bitm ap.