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146 Chapter 17: Rendering
\3dsmax8\plugcfg folder is where the Target Map
Slot assignments are stored.
Creati ng and Using Nor ma l B ump
Maps
Normal bump mapping is a way of adding
high-resolution detail to low-polygon objects. It
is especially useful for real-time display devices
such as game engines, and it can also be used in
rendered scenes and animations.
A normals map is a three-color map, unlike the
grayscale maps used for regular bump mapping
(see
Bump Mapping (p age 2–1347) ). The red
channel encodes the left-rig ht axis of normal
orientation, the green channel encodes the
up-down axis of normal orientation, and the blue
channel encodes vertical depth.
Basic Workflow
3ds Max prov ides a number of different ways
to create and use normal bump mapping, but
the most straightforward and simplest workflow
involves these steps:
1. Create a detailed, high-resolution model.
2. Create a simpler, low-resolution model.
The low-resolution model should have
thegeneralshapeandoutlinesofthe
high-resolution model, and typically it should
be a bit sm al ler, so that projected detail in t he
high-resmodelwillappeartobeaboveits
surface.
3. Select the low -res model.
4. Choose Rendering > Render to Texture.
The Render To Texture dialog appears.
5. On the Objects To Bake rollout, in the
Projection Mapping group, click Pick.
Aselectiondialogappears.
6. Cho ose the hig h-res object, and then click Add.
3dsMaxappliesa
Projection modifier (page
1–760)
to the low-res object.
7. In the Projection Mapping group, turn on
Enable.
Note: At this stage, often you will click Options
to display the
ProjectionOptionsdialog(page
3–160)
,whichhasavarietyofsettingsforhow
to generate the projection.
8. On the Output rollout, add a N ormalsMap
element (see
Baked Texture Elements (page
3–142)
). Assig n Bump as its target map slot.
9. IntheSelectedElementsUniquesettingsgroup,
turn on Output Into Normal Bump.
10.Click Render.
3dsMaxrenderstheNormalsmap,which
stores normals data from the high-res object.
As for other kinds of texture baking, it creates
a Shell mater ial and applies that to the low-res
object, with the Normals m ap assigned as the
bump component.
Components of Nor mal B ump Ma pping
In the 3ds Max interface, controls for normal
bump maps appear in three locations:
• The Rende r To Te x t u r e d i a log
Specifically, normal projection controls are
found on the
Objects To Bake rollout (page
3–153)
and the Output rollout (page 3–155) .
•The
Project ion mo difier (page 1–760)
You can apply a Projection modifier yourself, or
let Render To Texture do so automatically.
•The
Normal Bump map type (page 2–1541)
Render To Texture creates this automatically if
youturnonOutputIntoNormalBump(step
9, above).