This brings up the "Transparency type" selection menu for the viewer that has the following controls:
Screen-door
This option when selected uses a fill pattern to simulate transparency effects (fastest, least photo-realistic)
Alpha blending
Alpha blending option produces more realistic transparency effects (slowest, most photo-realistic). Alpha blending types are as follows:
Additive
Additive blending option adds the transparent object to the colors already in the frame buffer.
Delayed additive
Renders opaque objects first and transparent objects last.
Sorted delayed additive
Draws opaque objects first followed by transparent objects, then sorts the transparent objects by their distance from the camera and draws them from back to front.
Multiplicative
Combines source and destination colors and alpha factor to produce transparency effects.
Delayed multiplicative
Renders opaque objects first and transparent objects last.
Sorted delayed multiplicative
Draws opaque objects first, then transparent. Transparent objects are sorted by their distance from the camera and drawn from back to front.