8

908 Chapter 8: Modifiers
texture map appears in the scene with the correct
scaling.
There are two parts to the equation in order for
real-world mapping to work. First, the correct
style of UV texture coordinates must be assigned
tothegeometry.Basically,thesizeoftheUVspace
needs to correspond to the size of the geometry.
Therefore, a new switch, called
Real-World Map
Size
, has been added to many of the dialogs
and rollouts w here you can generate texture
coordinates. Any dialog or rollout in which you
have the option to turn on
Generate Mapping
Coords
,alsohasaswitchwhereyoucanturnon
Real-World Map Size .
Note: There are a few primitive objects that do not
have a Real-World Map Size switch. These are
Torus Knot, Hedra, Prism and RingWave.
The other part of the equation is i n the material
editor. When you create a material and use a 2D
texture map, you now see a new switch in the
Coordinates rollout called
Use Real-W orld Scale .
When this switch is turned on, the default, the
Width and Height spinners are enabled that let
you specify the horizontal/vertical offsets and size
of the texture map in current
display units (page
3–891)
.
Note: Autodesk VIZ scenes with objects using
real-world mapping coordinates will display
differentlywhenopenedin3dsMax. Thisis
because real-world mapping coordinates is not the
default method of generating mapping coordinates
in 3ds Max.
Pr ocedur es
To apply the UV W M ap modif ier :
1.
Assign a mapped material to an object.
2. On the Modify p anel, choose UVW
Map from the Modifier List.
3. Adjust the mapping parameters.
By default, the UVW Map modifier uses planar
mapping on map channel 1. You can change the
type of mapping and the map channel to suit
your needs. There are seven types of mapping
coordinates, ninety-nine map channels, tiling
controls, and controls to size and orient the
mapping gizmo in the UVW Map modifier.
Note: If a UVW Map modifier is applied to
multiple objects, the UVW Map gizmo is
definedbytheselection,andthemappingthat
results is applied to all the objects.
TousemultipleUVWchannelsinthesameobject:
1.
Assign Map channel 1 to an object. You can do
this by either tur ning on Generate Mapping
Coordinates in the Parameters rollout of
anyprimitive,orbyassigningaUVWMap
modifier with channel 1 chosen.
Generate Mapping Coordinates uses map
channel 1 by default.
2. Assign a UVW Map modifier (or a second one,
if you’re using the first to assign channel 1) .
Choose channel 2 for this modifier.
Both coordinate channels are now assigned
to the geometry. The next step is to assign a
mapped material that uses b oth channels.
3. Createamaterialwithtwomaps.Youcando
this using a Composite map, or a Blend material
with two maps, or you can have one map
assigned to Diffuse and a nothe r assigned to
Bump. Perhaps the easiest way to see the effect
is to composite two maps, with the second map
containing an alpha channel.
4. Go to the level of one of the maps and, in the
Mapping list, choose E xplicit Map Channel 2.
The other map is already assigned channel 1
by default.
5. Assign the mapped material to the object.
You can switch between viewing the maps in
the viewport using the Show Map In Viewport