2008

Map Channel
Left: Scene uses different map channels to place different copies of the same maps in
different locations.
Right: The three maps used to create the streets and the traffic markers painted on
them
When you turn on Generate Mapping Coordinates for an object, the
coordinates use map channel 1. You can assign new map channels with new
mapping coordinates by applying a
UVW Map modifier on page 1849 to the
object. Map channel values can range from 1 to 99.
A map channel associates a map with an object's mapping coordinates.
Texture-baked maps on page 6169 also use map channels.
For
NURBS on page 2152 surface sub-objects, you can assign a map channel
without applying UVW Map. The surface sub-object has a different set of
mapping coordinates for each map channel you use.
A map's map channel value identifies which of an object's mapping coordinates
to use. Different map channels allow maps for the same object to use different
coordinates. For example, you might use one channel for
diffuse mapping
on page 5364 and a different one for bump mapping on page 5382 . Map channels
also let different maps use different coordinates within a
compound material
on page 5544 , a compositor map on page 5756 , or a multi/sub-object on page
5558 material.
Different map channels can have different U and V tiling values, different U
and V offsets, and so on. In the UVW Map modifier, you can also set different
map channels to have different mapping types (planar, cylindrical, spherical,
and so on).
If you apply a map that uses a certain map channel to an object that has no
mapping coordinates for that channel, the map doesn't appear on the object.
7836 | Glossary