Brightness and Contrast work just like the contrast and brightness on a television.
Each procedural texture works by varying a value between 0.0 and 1.0. This means that if you added a procedural texture and set the low color to black and the high color to white you would get a blend, black to white. So using the above example a brightness of 0.0 sets the texture to go black to white. If the brightness is lowered then the combiner get darker and will become more black. Conversely, if the Bias is raised the combiner get lighter and tend towards being white. As far as the Gain is concerned this controls the point at which the combiner starts to darken and starts to lighten (in other words the width of the light to dark transition). At a value of 0.0 the combiner will start black and vary continually until it becomes white. As the gain is lowered this transition spreads so that over the combiner's range it will only go from dark grey to light gray. If the Gain is raised the transition get smaller so that the fade black to white happens quicker until at the very highest values it is a discrete step. By varying the Brightness and Contrast a full range of effects can be created provided an infinite range of procedural textures. The table bellow shows just some of the effects of the Gain and Bias when using the Enhance:DT Noise - fBm Texture.
|Bias 0%||Bias 25%||Bias 50%||Bias 75%||Bias 100%|