
Viewer can be changed between 2D and PD.
Background color can be change if 2D mode. Look at Control
panel, [Properties] - [Settings] - [Background color].
Look at Effects.

Show shadow
Shadow is shown behind character. It is not exactly the same as
UO.

Shadow only
When Show shadow is checked, this button gets available.
Shadow is shown without character.

This feature is useful to turn it into real shadow.
Shadow in UO is some transparent. So you can make it transparent
with an image editorial software.
UOC color code
UOC
standard is the color standards suggested by Milano, popular among
Japanese UO players. By this button, explanations on the color
buttons can be changed between hexadecimal and UOC.

Hiding
Character gets hiding color. The color is not exactly the same
as UO.

Mask Saying (Mask Speech)
Hide speech. Speech data isn't reset.

Silhouette
Character becomes Silhouette.

Ghost
Character becomes ghost. Outfit data is not reset.