6.6  Interior

Introduced in POV-Ray 3.1 is an object modifier statement called interior. The syntax is:

INTERIOR:
    interior { [INTERIOR_IDENTIFIER] [INTERIOR_ITEMS...] }
INTERIOR_ITEM:
    ior Value | caustics Value | dispersion Value | 
    dispersion_samples Samples | fade_distance Distance | 
    fade_power Power | fade_color <Color>
    MEDIA...

Interior default values:

ior                : 1.0
caustics           : 0.0
dispersion         : 1.0
dispersion_samples : 7
fade_distance      : 0.0 
fade_power         : 0.0
fade_color         : <0,0,0>

The interior contains items which describe the properties of the interior of the object. This is in contrast to the texture and interior_texture which describe the surface properties only. The interior of an object is only of interest if it has a transparent texture which allows you to see inside the object. It also applies only to solid objects which have a well-defined inside/outside distinction.

Note: the open keyword, or clipped_by modifier also allows you to see inside but interior features may not render properly. They should be avoided if accurate interiors are required.

Interior identifiers may be declared to make scene files more readable and to parameterize scenes so that changing a single declaration changes many values. An identifier is declared as follows.

INTERIOR_DECLARATION:
    #declare IDENTIFIER = INTERIOR |
    #local IDENTIFIER = INTERIOR

Where IDENTIFIER is the name of the identifier up to 40 characters long and INTERIOR is any valid interior statement. See "#declare vs. #local" for information on identifier scope.