Fast Volume Effects

Category: Volume

Shader Family: Volume

Output: Color

When used with the Fast Light Effects shader, gives a volumetric effect to lights. Both the Fast_volume_effects and the Fast_light_effects shaders must be used for each light that is to receive volumetric effects. If no Fast_light_effects shader is used, the light will have no volumetric effects.

Fast_Volume_Effects

si_default

start	Specifies where the volumetric effect begins (completely transparent).
stop	Specifies where the volumetric effect ends (completely opaque).
rate	Specifies the transparency of the volumetric effect. 0 = completely transparent and will not obscure light; 1 = opaque.
transmit	Specifies the color of the volumetric effect that light rays are faded into.
light rays	Specifies whether or not light rays are also attenuated by the volumetric effect. When on, light illumination is subject to volumic attenuation; when off, lights can illuminate objects at any distance regardless of the volumetric effect.

Volumic

Lights

Creates a light list to specifiy which lights should produce the effect. For more information, see Using Light Lists [Direct Illumination].

Sampling

Feature Size	Controls the steps of a volume map. Use this to "smooth" the volumic effect.
Max Ray Length	Sets an upper limit on the distance that light rays travel in a volumic environment.

Smoke

Smoke	When on, it overlays a "smoky" effect over the volumetric effects.
Depth Fading	When on, it Switches on the calculation of depth fading in addition to the volumetric effects.
3D Smoke	Specifies the Z-depth of the smoke.
Scale	Specifies the size of the smoke.
Intensity	Specifies the thickness, or density, of the smoke.
Animation Speed	Specifies the distance smoke will travel over time.