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196 Chapter 11: Space Warps and Particle Systems
Procedure
Example: To animate par ticle color ing using the
Mapping operator:
1.
Open the Material Editor
,andcreatea
material that uses Gradient Ramp as the Diffuse
map.
2. On the map’s Gradient Ramp Parameters
rollout, make sure Gra
dient Type is set to
Linear.
3. Create a colorful gradient. The Mapping
operator uses the colors in left-to-right order as
the U value increases
from 0.0 to 1.0.
4. Add a Particle Flow So
urce object to the scene.
5. Open Particle View.
6. In Event 01, click the
Speed operator and set
Speed to 100.
7. In Event 01, click Display and set Type to
Geometr y.
8. Add a Material Static operator to Event 01, and
then click the opera
tor in the event.
9. Drag the material yo
u created f rom its Material
Editor sample slot to the button (labeled
“None ”) on the Material Static parameters
rollout in Particl
eView.
10. Add a Mapping opera
tor to Event 01, and then
click the operator in the event.
11. On the Mapping rollout in Particle View, turn
on Show Map In Viewport.
12. Go to frame 100 and
turn on Auto
Key .
13. On the Mapping rollout in Particle View, set
Map Values > U=1.0.
14. For Sync By, choose Particle Age.
15. Turn off Auto Key, and click
Play Animation
.
As each particle is born and falls, its U mapping
coordinate gradually changes from 0.0 to
1.0, while its color changes to match the
corresponding position across the Gradient
Ramp map.
To vary the effect, try changing the Gradient
Type sett ing, and animate the V and W values
as well. O r, for more s ophisticated effects,
assign animation controllers such as Noise
Float to the Mapping coordinate values, or
w ire them to other changing parameters in t he
scene (Animation menu > Wire Parameters >
Parameter Wire Dialog).
Tip: In the Material Editor, it’s easier to see the
resultoftheGradientTypechoiceifyouset
Sample Type to Cube.
Interfa ce
The user interface appears in the parameters panel,
on the right side of the Particle View dialog.
Map Values group
U/V/W—Set t he coordinates on the m ap from
which the particle color is taken. One pixel from
this location is used to color the entire particle.
In general, U and V represent the horizontal a nd
vertical dimensions, respectively, beginning at the