Symbol Mapper: Pre-process Group

Depending on your settings, Symbol Mapper can change which characters display in a given space according to that location’s underlying brightness values, with larger characters sometimes providing more apparent brightness in a space. (Spoiler: You can best see this behavior with Random Seed set to 0, Symbol Limit at 64, and All Characters checked, or you can select one of the Density presets.) The Pre-process group offers two controls that change the brightness of the underlying source content, Brightness and Contrast, and thus can influence which symbols get mapped into the Symbol Mapper effect.

Brightness values can range from -150 to 150. The following image shows an example of raising the default Brightness value of 0 to 100. Note that we also have Glow Intensity set to 100 (not shown) to accentuate the impact of changing the Brightness. You’ll observe how the characters selected by Symbol Mapper change based solely on underlying brightness values.

For a slightly different look at how Symbol Mapper makes these choices, let’s run the Contrast control from its lowest (-100) to highest (100) value.

At -100, Symbol Mapper fills the preview with glowing white dollar symbols. This may seem counter-intuitive, but keep in mind that Brightness is at 100. Contrast at -100 presents a uniform gray across the screen while, at 100, Contrast pushes everything toward lights and darks.