Category
Background: How the area behind the model appears, such as graduated colors or clouds.
Cubical Maps: Maps a photo image.
Foreground: How the area in front of the model appears, such as snow or fog.
HDRI:
Images: Applies an image as the model background. The graphic can be in .bmp, *.jpg, *.tif, or *lwi format. *Plain: Applies a plain color as the model background.
Tone: Brightens the model or moves the perspective up or down.
Environment: This field depends on the category.
Plain: several colors will appear.
Edit Environment: Opens the Environments Editor. See Editing Environments.