Autodesk 12812-051462-9011 User Guide 3 - Page 1476

Link To Light Links the noise effect to its light object, rather than to world coordinates. Usually you want noise to look like fog or dust motes in the atmosphere, in which case, as the light moves, the noise should remain with the world coordinates. For certain special effects, however, you might want the noise linked to the light's coordinates. In these cases, turn on Link to Light. Type Choose one of three types of noise to apply. ■ Regular The standard noise pattern. ■ Fractal An iterative fractal noise pattern. ■ Turbulence An iterative turbulence pattern. Invert Reverses the noise effect. Dense fog becomes translucent and vice versa. Noise Threshold Limits the noise effect. When the noise value is above the Low threshold and below the High threshold, the dynamic range stretches to fill 0-1. This makes for a smaller discontinuity (first order instead of 0 order) at the threshold transition and thus produces less potential aliasing on page 7904. ■ High Sets the high threshold. Range=0 to 1.0. ■ Low Sets the low threshold. Range=0 to 1.0. Uniformity Acts like a high-pass filter: the smaller the value, the more the volume is transparent with discrete blobs of smoke. By around -0.3 or so your image begins to look like specks of dust. Because the fog becomes thinner as this parameter gets smaller, you'll probably need to increase the density or the volume will start to disappear. Range=-1 to 1 Levels Sets the number of times the noise is iteratively applied. This parameter is animatable. Enabled only for Fractal noise or Turbulence. Range=1 to 6, including fractional values. Size Determines the size of the tendrils of smoke or fog. Smaller values give smaller tendrils. Volume Light Environment Effect | 6731