9

Baked Texture Elements 149
Blend Map
A blend map is like a complete map , except that all
itscomponents,notjustshadows,areoptional.
Component Options (Selected Eleme nts Unique
Settings)
For a blend map, you can choose not to render any
of the following components:
•Lighting
•Diffusecolor
• Specular color
•Reflections
•Shadows
•Ambientcolor
•Self-illuminationcolor
•Refractions
Alpha M ap
An alpha map saves only the a lpha channel of the
rendered object.
Component Options (Selected Eleme nts Unique
Settings)
There are no unique settings for a n a lpha map.
Ambient Occlusion (MR) Map
Useanambientocclusionmapwhenyouwant
the surface informa tion to describe how much
ambient light the surface can receive. The ambient
occlusion map considers the obstruction of
the light by surface contours and surrounding
objects. By using the ambient occlusion map
when rendering, you do not need to set up special
lighting , replace materials on the objects, or
usewithglobaloverridesbecausetheambient
occlusion map already accounts for these sett ings.
You can use ambient occlusion maps with or
without a Projection modifier and for man y
different purposes. Use them to mask layers in
Adobe Photoshop, for items such as painted edits
and texture maps. Also use them as dirt maps, or
asmasksforreflectionsorspecularlight.
Note: By default, the shader used by the
Ambient Occlusion bake element excludes
the low-resolution object from the ambient
occlusion calculations whenever performing
projection-mapped texture baking. However, if
the Projection Mapping option Include W orking
Model is enabled, then the occlusion rays will
include the working model. In this case, project ion
rays also include the working model. No undesired
blank areas appear on the map, because there are
no cases where a projection ray p a sses though the
lo-res model to hit a point on the high-res model
that is completely occluded by the low res.
Note: This map is available only when the mental
ray renderer is active.
Original scene surrounded by rendered-to-texture ambient
occlusion maps of the floor object
Top left: Samples=8; Spread=0.8
Top right: Samples=32; Spread=0.8
Bottom left: Samples=16; Spread=0.5
Bottom right: Samples=16; Spread=0.99