9.5.2

910 • CHAPTER 18
THE SHADERS • 911
Fire
The wall of ame stretches innitely in the U direction. Good ame materials
can be created by using this shader both in the Alpha channel and the
Transparency channel.
This shader simulates a wall of re, whose color you can dene using the gradient. The Fire shader
has an alpha channel that you can use in the Material editor on the Alpha page. U Frequency and
V Frequency determine the neness of the structure. Thus U=1 and V=1 results in regular ames,
U=1 and V=0.25 gives rather elongated ames. T Frequency affects the speed of the icker, i.e.
how quickly the ames change — the higher the value, the faster the icker. Turbulence determines
how violently the ames break up in a notional wind. A setting of 2 doubles the wind; a setting of 0
suppresses all wind.
Flame
This shader simulates a single ame, whose color you can dene using the gradient. The Flame shader
has an alpha channel that you can use within the Material editor on the Alpha page. T Frequency
is a scaling factor that affects the speed of icker, i.e. how quickly the ame changes. Turbulence
determines how violently the ames break up in a notional wind. A setting of 2 doubles the wind; a
setting of 0 suppresses all wind.