9

Fire Environment Effect 281
Note:
100 percent transparent objects that
intersect the effect become partially visible.
To use p articles with Fire, consider using 3D
particles instead of opacity-mapped particles.
Motion group
Use the parameters in the Motion group to animate
the churning and rise of flames.
Phase—Controls the rate of change for the fire
effect. Turn on Auto Key and change the phase
value at different times.
Phase value can have several meanings, depending
on the state of the Explosion check box.
• If you clear Explosion, Phase controls the
churningofthefire. Thefasterthevalue
changes,themorefuriouslythefireburns.If
the Phase function curve is a line, you get a
steady burning fire.
• If you turn on Explosion, Phase controls the
churningofthefireandtheexplosiontiming,
using values between 0.0 to 300.0. The Phase
function curve for a typical explosion starts
steep and flattens out.
Phase values control explosion timing in the
following way:
Value Ex plosion Effect
0–100
Explosion begins and bu ilds to peak density
at 100.
100–200
Explosion burns. Effect turns to smoke if
Smoke is turned on.
200–300
Explosionclearsandiscompletelygoneat300.
>300
No effect.
Phase Function Cur ve Sample
Explosion effect at Phase=50, 100, 150, 200, and 250
Drif t—Sets how flames are rendered along the Z
axisofthefireapparatus.Thevalueistheamount
of rise in units.
Low values give a slow-burning cool fire.
High values give a fast-burning hot fire.
For the best fire effects, drift should be a multiple
of the height of the fire apparatus.
You can also animate the location and size of the
fire apparatus and most of the fire parameters. For
example, a fire effect can animate color, size, and
density.
Explosion group
Use the parameters in the Explosion group to
automatically animate explosions.
Explosion—Animates size, density, and color
automatically based on the animation of the Phase
value.
Smoke—Controlswhetherornottheexplosion
creates smoke.
When on, fire colors change to smoke between
Phase values 100 to 200. Smoke clears between
Phase values 200 to 300. When off, fire colors
remain at ful l density between Phase values 100
to 200. Fire fades away between Phase values 200
to 300.
Fury—Varies the churning effect of the Phase
parameter.
Values greater than 1.0 cause faster churning.
Values less than 1.0 cause slower churning.