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1694 Chapter 16: Material Editor, Materials, and Maps
can assign vertex colors using the Ve r tex Pa int
Modifier (page 1–936),theAssign Vertex Colors
utility (page 2–1734),orthevertexcontrolsforan
editable mesh (page 1–1003), editable patch (page
1–975),oreditable poly (page 1–1029).
While vertex color assig nment is primar ily used
for special applications, such as game engines or
radiosity renderers, you can also use it to create
colorful, gradient surface effects. You can also
use it in desig n visual ization: Use the Ve r tex Pa int
Modifier (page 1–936) to paint your landscape
different colors to represent grass, shrubbery,
parking areas, etc., and then use Vertex Color
map to use the vertex coloring in your rendered
images. Incidentally, when you use the Te r rain
object’s (page 1–347) Color By Elevation function,
the software assigns a material that uses a Vertex
Color map as the diffuse component.
Tip: To view vertex colors in a viewport, right-click
the object, choose Properties from the quad menu,
and then turn on Vertex Channel Display in the
Display Properties group.
Procedure
To use the vertex color map:
1.
Assign vertex colors to an object.
2. Assign a material to the object, then assign
a Vertex Color map to the material’s diffuse
component.
3. Optionally, if manipulating the map channels
w ith the Channel Info utility (page 2–1738),
choose a map channel or sub-channel to render.
4. Render the scene.
Interfa ce
These parameters let you define which map
channel or sub-channel is to be rendered. One
application is to support usage of the Vertex Color
map in conjunction with the Channel Info utility
(page 2–1738).
The sett ings are interlinked; changing one
parameter will change the other two, as
appropriate.
Map Channel—Lets you specify which map channel
to use. Range=0 to 99. Default=0.
Notes regarding this setting:
• If you set Map Channel to a channel that doesn’t
contain any vertex coloring data, attempting to
render will generate a Missing Map Coordinates
error message. To resolve this, apply vertex
coloring to tha t channel.
• By default, the vertex coloring in map channel
1 is a color gradient derived fro m the UVW
texture coordinates by converting UVW values
to RGB values. Thus, at UV=0,0 (the lower-left
corner of the map), the coloring is black; at
UV=1,0, the coloring is red, and at UV=1,1
(the upper-right corner), the coloring is yello w
(red + green=yellow). You can change these
colors with a tool such as VertexPaint modifier
(page 1–936).
• Map Channel cannot b e set to a negative value,
thus the m ap doesn’t support rendering of the
vertex illumination (-1) or vertex alpha (-2)
channel.