The RenderMan Interface - Paul Bourke

4.2.10 Bound
The graphics state maintains a bounding box called the current bound. The rendering program
may clip or cull primitives to this bound.
RiBound ( RtBound bound )
This procedure sets the current bound to bound. The bounding box bound is specified
in the current object coordinate system. Subsequent output primitives should all lie
within this bounding box. This allows the efficient specification of a bounding box
for a collection of output primitives.
RIB BINDING
Bound xmin xmax ymin ymax zmin zmax
Bound [xmin xmax ymin ymax zmin zmax]
EXAMPLE
Bound [0 0.5 0 0.5 0.9 1]
SEE ALSO
RiDetail
4.2.11 Detail
The graphics state maintains a relative detail, a current detail, and a current detail range. The
current detail is used to select between multiple representations of objects each characterized
by a different range of detail. The current detail range is given by 4 values. These
four numbers define transition ranges between this range of detail and the neighboring
representations. If the current detail lies inside the current detail range, geometric primitives
comprising this representation will be drawn.
Suppose there are two object definitions, foo1 and foo2, for an object. The first contains more
detail and the second less. These are communicated to the rendering program using the
following sequence of calls.
RiDetail ( bound );
RiDetailRange ( 0., 0., 10., 20. );
RiObjectInstance ( foo1 );
RiDetailRange ( 10., 20., RI INFINITY, RI INFINITY);
RiObjectInstance ( foo2 );
The current detail is set by RiDetail. The detail ranges indicate that object foo1 will be drawn
when the current detail is below 10 (thus it is the low detail detail representation) and that
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