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1444 Chapter 16: Material Editor, Materials, and Maps
Placing a bitmap lets you scale the map and place
it anywhere within its tile. Placing can change
thebitmap’sscale,butshowstheentirebitmap.
The four values that specif y the placement and
size of the cropping or placement region are all
animatable.
Cropping and placement settings affect the bitmap
only as it’s used for t his map and any instances of
themap.Theyhavenoeffectonthebitmapfile
itself.
Apply—Turn on to use the cropping or placements
settings.
View Image—Displays a rendered frame window
(page 3–5)
that shows the bitmap surrounded by
aregionoutline.Theregionoutlinehashandles
at its sides and corners. When cropping is on,
dragg ing the handles changes the size of the crop
area. You can also d rag within t he region area to
move it.
The frame window has U/V and W/H
(width/height) spinners on its toolbar. Use these to
adjust the location and size the image or crop area.
When Place is turned on, dragging the region
area handles changes the scale of the bitmap (hold
down CTRL to preserve the bitmap’s aspect r atio),
and drag ging the image changes its location within
thetilearea.
When Crop is turned on, the UV or XY button at
the right of the rendered frame window toolbar lets
you s witch b etween using UV or XY coordinates
in the toolbar spinners. Also, you can zoom out by
pressing SHI FT +Z and zo om in by pressing Z.
Cr o p —Makescroppingactive.
Place—Makes placement active.
U/V—Adjusts the bitmap location.
W/H—Adjusts the width and height of the bitmap
or crop area.
Jitter Pl acement—Specifies the amount of random
offset. At 0, there is no random offset. Range =
0.0 to 1.0
WhenPlaceisturnedon,thesizeandposition
specified by the spinners or editing window are
ignored. The software then chooses a random size
andtilepositionfortheimage.
Alpha Source group
Controls in this group determine the s ource of the
Output alpha channel in terms of the input bitmap.
Image Alpha—Uses the image’s alpha channel
(disabled if the image has no alpha channel).
RGB Intensity—Converts the colors in the bitmap
to grayscale tonal values and uses them for
transparency. Black is transparent and white is
opaque.
None (O paque)—Does not use transparency.
Premultiplied Alpha—Determines how alpha is
treated in the bitmap. When turned on, the
default,
premultiplied alpha (page 3–1091) is
expected in the file. When turned off, the alpha is
treated as non-premultiplied, and any RGB values
are ignored.
Tip: If you apply an alpha image as a Diffuse map,
for example, and it doesn’t decal correctly, the
bitmap file pr obably contains non-premultiplied
alpha; the RGB va lues are maintained separately
from the alpha values. To correct this, turn off
Premultiplied Alpha.
Time rollout