9

Reflection and Refraction Maps 1695
Sub Channel—
Lets you can specify that t he map
will use either the Red, Green, or Blue sub-channel
of the specified map channel, or all sub-channels.
Channel Name—After assigning the material with
the Vertex Color map to an object with named
map or vertex-color channels (see Channel Info
Utility (page 2–1738)), you can click Upd ate, and
then, from this drop-down list, choose a named
map channel from the object.
Update—Refreshes the contents of the Channel
Name drop-down list. Use Update after applying
the material to an object, or after adding channels
to the object.
Note: There could be conflicts if one material
w ith a Vertex Color map is assigned to objects
w ith different named Map Channels, w here one
channel’s name may be displayed in preference to
another’s.
R ef lecti on a nd R ef r acti on
These maps, grouped as "Other" in the
Material/Map Browser (page 2–1412),aremaps
that create reflections and refractions. Each of the
following maps has specific uses:
Flat Mirror (page 2–1695): Generates reflect ions
for flat surfaces. You assign it to faces rather than
to the object as a whole.
Raytrace (page 2–1698):Createsaccurate,fully
raytracedreflectionsandrefractions.
Reflect/Refract (page 2–1699): Generates
reflections or ref ractions automatically, based on
surrounding objects a nd the environment.
Thin Wall Refraction (page 2–1703): Generates
refractions automatically, simulating objects and
the environment seen through a refractive materia l
such as glass or water.
Fla t M ir r or M ap
Material Editor > Maps rollout > C lick a Map button. >
Material/Map Browser > Flat Mirror
Flat mirror map reflects the ice-cream shop’s interior.
The Flat Mirror (page 3–942) map produces a
material that reflects surrounding objects when
it is applied to a collection of coplanar faces.
You assign it as a material’s reflection map (page
2–1508).
Reflect/Refract maps don’t work well for flat
surfaces because each face reflects part of the
environment based on w here its surface normal
points. Using this technique, a large flat face can
reflect only a small part of the environment. Flat
Mirror automatically generates a reflection that
encompasses a larger part of the environment, to
better simulate a mirror-like surf ace.
Rules f or Using Flat Mir ror
Flat Mirror cannot generate reflections correctly
unless you observe these rules:
• Assign Flat Mirror to selected faces only.
Therearetwowaystodothis.Youcanmake
the Flat Mir ror material a sub-mater ia l of a
Multi/Sub -O b ject (page 2–1594) material, or
you can use the Apply To Faces With ID cont rol.